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Hung SY, Chung HY, Luo ST, Chu YT, Chen YH, MacDonald IJ, Chien SY, Kotha P, Yang LY, Hwang LL, Dun NJ, Chuang DM, Chen YH. Electroacupuncture improves TBI dysfunction by targeting HDAC overexpression and BDNF-associated Akt/GSK-3β signaling. Front Cell Neurosci 2022; 16:880267. [PMID: 36016833 PMCID: PMC9396337 DOI: 10.3389/fncel.2022.880267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/27/2022] [Indexed: 11/18/2022] Open
Abstract
Background Acupuncture or electroacupuncture (EA) appears to be a potential treatment in acute clinical traumatic brain injury (TBI); however, it remains uncertain whether acupuncture affects post-TBI histone deacetylase (HDAC) expression or impacts other biochemical/neurobiological events. Materials and methods We used behavioral testing, Western blot, and immunohistochemistry analysis to evaluate the cellular and molecular effects of EA at LI4 and LI11 in both weight drop-impact acceleration (WD)- and controlled cortical impact (CCI)-induced TBI models. Results Both WD- and CCI-induced TBI caused behavioral dysfunction, increased cortical levels of HDAC1 and HDAC3 isoforms, activated microglia and astrocytes, and decreased cortical levels of BDNF as well as its downstream mediators phosphorylated-Akt and phosphorylated-GSK-3β. Application of EA reversed motor, sensorimotor, and learning/memory deficits. EA also restored overexpression of HDAC1 and HDAC3, and recovered downregulation of BDNF-associated signaling in the cortex of TBI mice. Conclusion The results strongly suggest that acupuncture has multiple benefits against TBI-associated adverse behavioral and biochemical effects and that the underlying mechanisms are likely mediated by targeting HDAC overexpression and aberrant BDNF-associated Akt/GSK-3 signaling.
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Affiliation(s)
- Shih-Ya Hung
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
- Division of Colorectal Surgery, China Medical University Hospital, Taichung, Taiwan
| | - Hsin-Yi Chung
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Sih-Ting Luo
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Yu-Ting Chu
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Yu-Hsin Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Iona J. MacDonald
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Szu-Yu Chien
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Peddanna Kotha
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Liang-Yo Yang
- Department of Physiology, School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
- Laboratory for Neural Repair, China Medical University Hospital, Taichung, Taiwan
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Nae J. Dun
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, United States
| | - De-Maw Chuang
- Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States
| | - Yi-Hung Chen
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
- Chinese Medicine Research Center, China Medical University, Taichung, Taiwan
- Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan
- *Correspondence: Yi-Hung Chen,
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Liang SL, Tong YS, Hwang LL, Huang YZ, Chen CY. CART Peptides Differently Regulate Firing Rates and GABAergic Synaptic Inputs of DMV Neurons Innervating the Stomach Antrum and Cecum of Adult Male Rats. Neuroendocrinology 2022; 112:555-570. [PMID: 34348334 DOI: 10.1159/000518690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/23/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIM Central administration of cocaine- and amphetamine-regulated transcript peptides (CARTp) alters gastrointestinal motility and reduces food intake in rats. Since neurons in the dorsal motor nucleus of the vagus (DMV) receive GABAergic and glutamatergic inputs and innervate the smooth muscle of gastrointestinal organs, we hypothesized that CARTp acts on the DMV or presynaptic neurons. METHODS We used 3,3'-dioctadecyloxa-carbocyanine perchlorate (DiO) retrograde tracing with electrophysiological methods to record DMV neurons innervating the stomach antrum or cecum in brainstem slices from adult rats. RESULTS DiO application did not change the electrophysiological properties of DMV neurons. CART55-102 had no effect on the basal firing rates of neurons in either the stomach antrum-labeled group (SLG) or cecum-labeled group (CLG). When presynaptic inputs were blocked, CART55-102 further increased the firing rates of the SLG, suggesting a direct excitatory effect. Spontaneous inhibitory postsynaptic currents (sIPSCs) occurred at a higher frequency in SLG neurons than in CLG neurons. CART55-102 reduced the amplitude and the frequency of sIPSCs in SLG neurons dose-dependently, with higher doses also reducing spontaneous excitatory postsynaptic currents (sEPSCs). Higher doses of CART55-102 reduced sIPSC and sEPSC amplitudes in CLG neurons, suggesting a postsynaptic effect. In response to incremental current injections, the SLG neurons exhibited less increases in firing activity. Simultaneous applications of current injections and CART55-102 decreased the firing activity of the CLG. Therefore, stomach antrum-projecting DMV neurons possess a higher gating ability to stabilize firing activity. CONCLUSION The mechanism by which CARTp mediates anorectic actions may be through a direct reduction in cecum-projecting DMV neuron excitability and, to a lesser extent, that of antrum-projecting DMV neurons, by acting on receptors of these neurons.
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Affiliation(s)
- Shu-Ling Liang
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Yong-Sheng Tong
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Ling-Ling Hwang
- Department of Physiology, Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ying-Zu Huang
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
- Department of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Yen Chen
- Division of Gastroenterology and Hepatology, Taipei Veterans General Hospital, Faculty of Medicine, Institute of Emergency and Critical Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Chen YH, Chen YC, Hwang LL, Yang LY, Lu DY. Deficiency in Androgen Receptor Aggravates Traumatic Brain Injury-Induced Pathophysiology and Motor Deficits in Mice. Molecules 2021; 26:molecules26206250. [PMID: 34684832 PMCID: PMC8537172 DOI: 10.3390/molecules26206250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 11/16/2022] Open
Abstract
Androgens have been shown to have a beneficial effect on brain injury and lower reactive astrocyte expression after TBI. Androgen receptors (ARs) are known to mediate the neuroprotective effects of androgens. However, whether ARs play a crucial role in TBI remains unknown. In this study, we investigated the role of ARs in TBI pathophysiology, using AR knockout (ARKO) mice. We used the controlled cortical impact model to produce primary and mechanical brain injuries and assessed motor function and brain-lesion volume. In addition, the AR knockout effects on necrosis and autophagy were evaluated after TBI. AR knockout significantly increased TBI-induced expression of the necrosis marker alpha-II-spectrin breakdown product 150 and astrogliosis marker glial fibrillary acidic protein. In addition, the TBI-induced astrogliosis increase in ARKO mice lasted for three weeks after a TBI. The autophagy marker Beclin-1 was also enhanced in ARKO mice compared with wild-type mice after TBI. Our results also indicated that ARKO mice showed a more unsatisfactory performance than wild-type mice in a motor function test following TBI. Further, they were observed to have more severe lesions than wild-type mice after injury. These findings strongly suggest that ARs play a role in TBI.
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Affiliation(s)
- Yu-Hsin Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; (Y.-H.C.); (Y.-C.C.); (L.-L.H.)
| | - Yen-Chou Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; (Y.-H.C.); (Y.-C.C.); (L.-L.H.)
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; (Y.-H.C.); (Y.-C.C.); (L.-L.H.)
| | - Liang-Yo Yang
- Department of Physiology, School of Medicine, College of Medicine, China Medical University, Taichung 40402, Taiwan
- Laboratory of Neural Repair, Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
- Correspondence: (L.-Y.Y.); (D.-Y.L.); Tel.: +886-422-053-366 (ext. 1615) (L.-Y.Y.); +886-422-053-366 (ext. 2253) (D.-Y.L.)
| | - Dah-Yuu Lu
- Department of Pharmacology, School of Medicine, China Medical University, Taichung 404333, Taiwan
- Department of Photonics and Communication Engineering, Asia University, Taichung 404333, Taiwan
- Correspondence: (L.-Y.Y.); (D.-Y.L.); Tel.: +886-422-053-366 (ext. 1615) (L.-Y.Y.); +886-422-053-366 (ext. 2253) (D.-Y.L.)
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Li TL, Lee YH, Wu FH, Hwang LL. Orexin-A directly depolarizes dorsomedial hypothalamic neurons, including those innervating the rostral ventrolateral medulla. Eur J Pharmacol 2021; 899:174033. [PMID: 33727058 DOI: 10.1016/j.ejphar.2021.174033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 02/10/2021] [Accepted: 03/10/2021] [Indexed: 02/04/2023]
Abstract
The dorsomedial hypothalamus (DMH) receives dense orexinergic innervation. Intra-DMH application of orexins increases arterial pressure and heart rate in rats. We studied the effects of orexin-A on DMH neurons, including those innervating the medullary cardiovascular center, the rostral ventrolateral medulla (RVLM), by using whole-cell recordings in brain slices. In the presence of tetrodotoxin, orexin-A (30-1000 nM) depolarized 56% of DMH neurons (EC50 82.4 ± 4.4 nM). Under voltage-clamp recording, orexin-A (300 nM) induced three types of responses characterized by different current-voltage relationships, namely unchanged, increased, and decreased slope conductance in 68%, 14%, and 18% of orexin-A-responsive neurons, respectively. The reversal potential of the decreased-conductance response was near the equilibrium potential of K+ and became more positive in a high-K+ solution, suggesting that K+ conductance blockade is the underlying mechanism. In a low-Na+ solution, unchanged-, increased-, and decreased-conductance responses were observed in 56%, 11%, and 33% of orexin-A-responsive neurons, respectively, implying that a non-selective cation current (NSCC) underlies orexin-A-induced responses in a small population of DMH neurons. KBR-7943 (70 μM), an inhibitor of Na+-Ca2+ exchanger (NCX), suppressed orexin-A-induced depolarization in 7 of 10 neurons. In the presence of KBR-7943, the majority of orexin-A-responsive neurons exhibited decreased-conductance responses. These findings suggest that NCX activation may underlie orexin-A-induced depolarization in the majority of orexin-responsive DMH neurons. Of 19 RVLM-projecting DMH neurons identified by retrograde labeling, 17 (90%) were orexin-A responsive. In conclusion, orexin-A directly excited over half of DMH neurons, including those innervating the RVLM, through decreasing K+ conductance, activating NCX, and/or increasing NSCC.
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Affiliation(s)
- Tzu-Ling Li
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Yen-Hsien Lee
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, Hsinchu, Taiwan.
| | - Feng-Hsu Wu
- Division of General Surgery, Department of Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Dai YWE, Lee YH, Li TL, Hwang LL. Mechanisms of orexin 2 receptor-mediated depolarization in the rat paraventricular nucleus of the hypothalamus. Eur J Pharmacol 2020; 869:172802. [DOI: 10.1016/j.ejphar.2019.172802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 12/18/2022]
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Chen CY, Liao PL, Tsai CH, Chan YJ, Cheng YW, Hwang LL, Lin KH, Yen TL, Li CH. Correction to: Inhaled gold nanoparticles cause cerebral edema and upregulate endothelial aquaporin 1 expression, involving caveolin 1 dependent repression of extracellular regulated protein kinase activity. Part Fibre Toxicol 2019; 16:43. [PMID: 31739798 PMCID: PMC6862802 DOI: 10.1186/s12989-019-0329-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
It was highlighted that the original article [1] contained the wrong Fig. 1.
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Affiliation(s)
- Ching-Yi Chen
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.,School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Po-Lin Liao
- School of Pharmacy, Taipei Medical University, Taipei, Taiwan.,Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Chi-Hao Tsai
- Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Yen-Ju Chan
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Wen Cheng
- School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Ling-Ling Hwang
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Kuan-Hung Lin
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taiwan
| | - Ting-Ling Yen
- Department of Medical Research, Cathay General Hospital, Taipei, 22174, Taiwan
| | - Ching-Hao Li
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan. .,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Chen CY, Liao PL, Tsai CH, Chan YJ, Cheng YW, Hwang LL, Lin KH, Yen TL, Li CH. Inhaled gold nanoparticles cause cerebral edema and upregulate endothelial aquaporin 1 expression, involving caveolin 1 dependent repression of extracellular regulated protein kinase activity. Part Fibre Toxicol 2019; 16:37. [PMID: 31619255 PMCID: PMC6796418 DOI: 10.1186/s12989-019-0324-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 09/27/2019] [Indexed: 01/13/2023] Open
Abstract
Background Gold nanoparticles (Au-NPs) have extensive applications in electronics and biomedicine, resulting in increased exposure and prompting safety concerns for human health. After absorption, nanoparticles enter circulation and effect endothelial cells. We previously showed that exposure to Au-NPs (40–50 nm) collapsed endothelial tight junctions and increased their paracellular permeability. Inhaled nanoparticles have gained significant attention due to their biodistribution in the brain; however, little is known regarding their role in cerebral edema. The present study investigated the expression of aquaporin 1 (AQP1) in the cerebral endothelial cell line, bEnd.3, stimulated by Au-NPs. Results We found that treatment with Au-NPs induced AQP1 expression and increased endothelial permeability to water. Au-NP exposure rapidly boosted the phosphorylation levels of focal adhesion kinase (FAK) and AKT, increased the accumulation of caveolin 1 (Cav1), and reduced the activity of extracellular regulated protein kinases (ERK). The inhibition of AKT (GDC-0068) or FAK (PF-573228) not only rescued ERK activity but also prevented AQP1 induction, whereas Au-NP-mediated Cav1 accumulation remained unaltered. Neither these signaling molecules nor AQP1 expression responded to Au-NPs while Cav1 was silenced. Inhibition of ERK activity (U0126) remarkably enhanced Cav1 and AQP1 expression in bEnd.3 cells. These data demonstrate that Au-NP-mediated AQP1 induction is Cav1 dependent, but requires the repression on ERK activity. Mice receiving intranasally administered Au-NPs displayed cerebral edema, significantly augmented AQP1 protein levels; furthermore, mild focal lesions were observed in the cerebral parenchyma. Conclusions These data suggest that the subacute exposure of nanoparticles might induce cerebral edema, involving the Cav1 dependent accumulation on endothelial AQP1.
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Affiliation(s)
- Ching-Yi Chen
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.,School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Po-Lin Liao
- School of Pharmacy, Taipei Medical University, Taipei, Taiwan.,Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Chi-Hao Tsai
- Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Yen-Ju Chan
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Wen Cheng
- School of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Ling-Ling Hwang
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Kuan-Hung Lin
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei city, Taiwan
| | - Ting-Ling Yen
- Department of Medical Research, Cathay General Hospital, Taipei, 22174, Taiwan
| | - Ching-Hao Li
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan. .,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Chen PY, Chen CH, Chang CK, Kao CF, Lu ML, Lin SK, Huang MC, Hwang LL, Mondelli V. Orexin-A Levels in Relation to the Risk of Metabolic Syndrome in Patients with Schizophrenia Taking Antipsychotics. Int J Neuropsychopharmacol 2018; 22:28-36. [PMID: 30204875 PMCID: PMC6313111 DOI: 10.1093/ijnp/pyy075] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 09/01/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The role of orexin-A in regulating metabolic homeostasis has been recognized, but its association with antipsychotic-induced metabolic abnormalities remains unclear. We investigated the association between orexin-A levels and metabolic syndrome in patients with schizophrenia treated with clozapine or less obesogenic antipsychotics compared with nonpsychiatric controls. METHODS Plasma orexin-A levels and metabolic parameters were determined in 159 patients with schizophrenia: 109 taking clozapine; 50 taking aripiprazole, amisulpride, ziprasidone, or haloperidol; and 60 nonpsychiatric controls. RESULTS Orexin-A levels were significantly higher in the group taking less obesogenic antipsychotics, followed by the clozapine group and the controls (F=104.6, P<.01). Higher orexin-A levels were correlated with better metabolic profiles in the patient groups but not in the controls. Regression analyses revealed that the patients with higher orexin-A levels had significantly lower risk of metabolic syndrome (adjusted odds ratio [OR]=0.04, 95% CI: 0.01-0.38 for the 2nd tertile; OR=0.04, 95% CI: 0.01-0.36 for the 3rd tertile, compared with the first tertile), after adjustment for age, sex, smoking history, types of antipsychotics (clozapine vs less obesogenic antipsychotics), duration of antipsychotic treatment, and disease severity. CONCLUSIONS Our results revealed that the orexin-A level was upregulated in patients with schizophrenia treated with antipsychotics, especially for the group taking less obesogenic antipsychotics. Furthermore, higher orexin-A levels were independently associated with better metabolic profiles. These observations suggest that an upregulation of orexin-A has a protective effect against the development of metabolic abnormalities in patients with schizophrenia receiving antipsychotic treatment.
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Affiliation(s)
- Po-Yu Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan,Department of Psychiatry, Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan,Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
| | - Chun-Hsin Chen
- Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taiwan,Department of Psychiatry, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chin-Kuo Chang
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom,Department of Health and Welfare, University of Taipei, Taipei, Taiwan
| | - Chung-Feng Kao
- Department of Agronomy, College of Agriculture & Natural Resources, National Chung-Hsing University, Taichung, Taiwan
| | - Mong-Liang Lu
- Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taiwan,Department of Psychiatry, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ku Lin
- Department of Psychiatry, Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan,Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taiwan
| | - Ming-Chyi Huang
- Department of Psychiatry, Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan,Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taiwan,Psychiatric Research Center, Taipei Medical University Hospital,Correspondence: Ming-Chyi Huang, MD, PhD, Department of Psychiatry, Taipei City Psychiatric Center, Taipei City Hospital, 309 Song-de Road, Taipei 110, Taiwan (); and Ling-Ling Hwang, PhD, Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan ()
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan,Correspondence: Ming-Chyi Huang, MD, PhD, Department of Psychiatry, Taipei City Psychiatric Center, Taipei City Hospital, 309 Song-de Road, Taipei 110, Taiwan (); and Ling-Ling Hwang, PhD, Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan ()
| | - Valeria Mondelli
- Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom
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Huang SC, Li TL, Lee YH, Dai YWE, Chen YC, Hwang LL. Role of the orexin 2 receptor in palatable-food consumption-associated cardiovascular reactivity in spontaneously hypertensive rats. Sci Rep 2018; 8:12703. [PMID: 30140065 PMCID: PMC6107633 DOI: 10.1038/s41598-018-30970-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/31/2018] [Indexed: 01/19/2023] Open
Abstract
Hypertensive subjects often exhibit exaggerated cardiovascular reactivity. An overactive orexin system underlies the pathophysiology of hypertension. We examined orexin's roles in eating-associated cardiovascular reactivity in spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats. Results showed eating regular chow or palatable food (sucrose agar) was accompanied by elevated arterial pressure and heart rate. In both SHRs and WKY rats, the cardiovascular responses associated with sucrose-agar consumption were greater than that with regular-chow consumption. Additionally, SHRs exhibited greater cardiovascular responses than WKY rats did to regular-chow and palatable food consumption. Central orexin 2 receptor (OX2R) blockade attenuated sucrose-agar consumption-associated cardiovascular response only in SHRs. In both SHRs and WKY rats, OX2R blockade did not affect regular-chow consumption-associated cardiovascular responses. Greater numbers of c-Fos-positive cells in the rostral ventrolateral medulla (RVLM) and of c-Fos-positive orexin neurons in the dorsomedial hypothalamus (DMH) were detected in sucrose agar-treated SHRs, compared to regular chow-treated SHRs and to sucrose agar-treated WKY rats. Central OX2R blockade reduced the number of c-Fos-positive cells in the RVLM only in sucrose agar-treated SHRs. We concluded that in SHRs, orexin neurons in the DMH might be overactive during eating palatable food and may further elicit exaggerated cardiovascular responses via an OX2R-RVLM pathway.
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Affiliation(s)
- Shang-Cheng Huang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Tzu-Ling Li
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yen-Hsien Lee
- Cheng-Jian Biomedical Company Limited, Taipei, Taiwan
| | - Yu-Wen E Dai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Chun Chen
- School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Lin CS, Hsieh PS, Hwang LL, Lee YH, Tsai SH, Tu YC, Hung YW, Liu CC, Chuang YP, Liao MT, Chien S, Tsai MC. The CCL5/CCR5 Axis Promotes Vascular Smooth Muscle Cell Proliferation and Atherogenic Phenotype Switching. Cell Physiol Biochem 2018; 47:707-720. [DOI: 10.1159/000490024] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/27/2018] [Indexed: 11/19/2022] Open
Abstract
Background/Aims: Hyperlipidemia induces dysfunction in the smooth muscle cells (SMCs) of the blood vessels, and the vascular remodeling that ensues is a key proatherogenic factor contributing to cardiovascular events. Chemokines and chemokine receptors play crucial roles in vascular remodeling. Here, we examined whether the hyperlipidemia-derived chemokine CCL5 and its receptor CCR5 influence vascular SMC proliferation, phenotypic switching, and explored the underlying mechanisms. Methods: Thoracoabdominal aorta were isolated from wild-type, CCL5 and CCR5 double-knockout mice (CCL5–/–CCR5–/–) fed a high-fat diet (HFD) for 12 weeks. Expression of the contractile, synthetic, and proliferation markers were assayed using immunohistochemical and western blotting. The effects of CCL5 and palmitic acid on cultured SMC proliferation and phenotypic modulation were evaluated using flow cytometry, bromodeoxyuridine (BrdU), and western blotting. Results: Wild-type mice fed an HFD showed markedly increased total cholesterol, triglyceride, and CCL5 serum levels, as well as significantly increased CCL5 and CCR5 expression in the thoracoabdominal aorta vs. normal-diet-fed controls. HFD-fed CCL5-/-CCR5-/- mice showed significantly decreased expression of the synthetic phenotype marker osteopontin and the proliferation marker proliferating cell nuclear antigen, and increased expression of the contractile phenotype marker smooth muscle α-actin in the thoracoabdominal aorta vs. wild-type HFD-fed mice. Human aorta-derived SMCs stimulated with palmitic acid showed significantly increased expression of CCL5, CCR5, and synthetic phenotype markers, as well as increased proliferation. CCL5-treated SMCs showed increased cell cycle regulatory protein expression, paralleling increased synthetic and decreased contractile phenotype marker expression. Inhibition of CCR5 activity by the specific antagonist maraviroc or its expression using small interfering RNA significantly inhibited human aortic SMC proliferation and synthetic phenotype formation. Therefore, CCL5 induces SMC proliferation and phenotypic switching from a contractile to synthetic phenotype via CCR5. CCL5-mediated SMC stimulation activated ERK1/2, Akt/p70S6K, p38 MAPK, and NF-κB signaling. NF-κB inhibition significantly reduced CCR5 expression along with CCR5-induced SMC proliferation and synthetic phenotype formation. Conclusions: Hyperlipidemia-induced CCL5/CCR5 axis activation serves as a pivotal mediator of vascular remodeling, indicating that CCL5 and CCR5 are key chemokine-related factors in atherogenesis. SMC proliferation and synthetic phenotype transformation attenuation by CCR5 pharmacological inhibition may offer a new approach to treatment or prevention of atherosclerotic diseases associated with hyperlipidemia.
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Li TL, Chen JYS, Huang SC, Dai YWE, Hwang LL. Cardiovascular pressor effects of orexins in the dorsomedial hypothalamus. Eur J Pharmacol 2017; 818:343-350. [PMID: 29104046 DOI: 10.1016/j.ejphar.2017.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 10/27/2017] [Accepted: 11/01/2017] [Indexed: 10/18/2022]
Abstract
Orexins are important regulators of cardiovascular functions in various physiological and pathological conditions. The dorsomedial hypothalamus (DMH), an essential mediator of cardiovascular responses to stress, contains dense orexinergic innervations and receptors. We examined whether orexins can regulate cardiovascular functions through their actions in the DMH in anesthetized rats. An intra-DMH injection of orexin A (30pmol) produced elevation of arterial pressure and heart rate. Orexin A-sensitive sites were located within or immediately adjacent to the DMH and larger responses were induced at the compact part of the dorsomedial hypothalamic nucleus. Orexin A-induced responses were attenuated by intra-DMH pretreatment with an orexin receptor 1 (OX1R) antagonist, SB-334867 (15nmol) (17.7 ± 2.8 vs. 5.2 ± 1.0mmHg; 54.6 ± 10.0 vs. 22.8 ± 7.4 beats/min). Intra-DMH applied [Ala11,D-Leu15]-orexin B (300 pmol), an orexin receptor 2 (OX2R) agonist, elicited cardiovascular responses mimicking the responses of orexin A, except for a smaller pressor response (7.4 ± 1.7 vs. 16.4 ± 1.8mmHg). In a series of experiment, effects of orexin B (100pmol) and then orexin A (30pmol), were examined at a same site. Two patterns of responses were observed in 12 intra-DMH sites: (1) both orexin A and B (9 sites), and (2) only orexin A (3 sites) induced cardiovascular responses, respectively suggesting OX1R/OX2R-mediated and OX1R-predominant mechanisms. In conclusion, orexins regulated cardiovascular functions through OX1R/OX2R- or OX1R-mediated mechanisms at different locations in the DMH.
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Affiliation(s)
- Tzu-Ling Li
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Jennifer Y S Chen
- School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Shang-Cheng Huang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Yu-Wen E Dai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan; Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei 110, Taiwan.
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12
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Tung LW, Lu GL, Lee YH, Yu L, Lee HJ, Leishman E, Bradshaw H, Hwang LL, Hung MS, Mackie K, Zimmer A, Chiou LC. Orexins contribute to restraint stress-induced cocaine relapse by endocannabinoid-mediated disinhibition of dopaminergic neurons. Nat Commun 2016; 7:12199. [PMID: 27448020 PMCID: PMC4961842 DOI: 10.1038/ncomms12199] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 06/10/2016] [Indexed: 12/31/2022] Open
Abstract
Orexins are associated with drug relapse in rodents. Here, we show that acute restraint stress in mice activates lateral hypothalamic (LH) orexin neurons, increases levels of orexin A and 2-arachidonoylglycerol (2-AG) in the ventral tegmental area (VTA), and reinstates extinguished cocaine-conditioned place preference (CPP). This stress-induced reinstatement of cocaine CPP depends on type 1 orexin receptors (OX1Rs), type 1 cannabinoid receptors (CB1Rs) and diacylglycerol lipase (DAGL) in the VTA. In dopaminergic neurons of VTA slices, orexin A presynaptically inhibits GABAergic transmission. This effect is prevented by internal GDP-β-S or inhibiting OX1Rs, CB1Rs, phospholipase C or DAGL, and potentiated by inhibiting 2-AG degradation. These results suggest that restraint stress activates LH orexin neurons, releasing orexins into the VTA to activate postsynaptic OX1Rs of dopaminergic neurons and generate 2-AG through a Gq-protein-phospholipase C-DAGL cascade. 2-AG retrogradely inhibits GABA release through presynaptic CB1Rs, leading to VTA dopaminergic disinhibition and reinstatement of cocaine CPP. Stress is a major cause of relapse to cocaine seeking behaviour. Tung et al. show that orexin mediates stress-induced reinstatement of cocaine seeking behaviour in mice by endocannabinoid-dependent disinhibition in the ventral tegmental area.
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Affiliation(s)
- Li-Wei Tung
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Guan-Ling Lu
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yen-Hsien Lee
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, No. 250 Wuxing Street, Taipei 11031, Taiwan
| | - Lung Yu
- Institute of Behavioral Medicine, College of Medicine, National Cheng Kung University, No.1, University Road, Tainan City 70101, Taiwan
| | - Hsin-Jung Lee
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Emma Leishman
- Gill Center and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana 47405, USA
| | - Heather Bradshaw
- Gill Center and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana 47405, USA
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, No. 250 Wuxing Street, Taipei 11031, Taiwan.,Department of Physiology, College of Medicine, Taipei Medical University, No. 250 Wuxing Street, Taipei 11031, Taiwan
| | - Ming-Shiu Hung
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - Ken Mackie
- Gill Center and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana 47405, USA
| | - Andreas Zimmer
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Lih-Chu Chiou
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei 100, Taiwan.,Department of Pharmacology, College of Medicine, National Taiwan University, Taipei 100, Taiwan.,Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 100, Taiwan.,Research Center for Chinese Medicine &Acupuncture, China Medical University, Taichung 40447, Taiwan
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Dai YWE, Lee YH, Chen JYS, Lin YK, Hwang LL. Expression of the M3 Muscarinic Receptor on Orexin Neurons that Project to the Rostral Ventrolateral Medulla. Anat Rec (Hoboken) 2016; 299:660-8. [PMID: 26910770 DOI: 10.1002/ar.23329] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 12/10/2015] [Accepted: 12/22/2015] [Indexed: 11/11/2022]
Abstract
Activation of central cholinergic receptors causes a pressor response in rats, and the hypothalamus is important for this response. Projections from hypothalamic orexin neurons to the rostral ventrolateral medulla (RVLM) are involved in sympatho-excitation of the cardiovascular system. A small population of orexin neurons is regulated by cholinergic inputs through M3 muscarinic acetylcholine receptor (M3 R). To elucidate whether the M3 R on orexin neurons is involved in cardiosympathetic regulation through the RVLM, we examined the presence of the M3 R on retrograde-labeled RVLM-projecting orexin neurons. The retrograde tracer was unilaterally injected into the RVLM. Within the hypothalamus, retrograde-labeled neurons were located predominantly ipsilateral to the injection side. In the anterior hypothalamus (-1.5 to -2.3 mm to the bregma), retrograde-labeled neurons were densely distributed in the paraventricular nuclei and scattered in the retrochiasmatic area. At -2.3 to -3.5 mm from the bregma, labeled neurons were located in the regions where orexin neurons were situated, that is, the tuberal lateral hypothalamic area, perifornical area, and dorsomedial nuclei. Very few retrograde-labeled neurons were observed in the hypothalamus at -3.5 to -4.5 mm from the bregma. About 19.5% ± 1.6% of RVLM-projecting neurons in the tuberal hypothalamus were orexinergic. The M3 R was present on 18.7% ± 3.0% of RVLM-projecting orexin neurons. Injection of a muscarinic agonist, oxotremorine, in the perifornical area resulted in a pressor response, which was attenuated by a pretreatment of atropine. We conclude that cholinergic inputs to orexin neurons may be involved in cardiosympathetic regulation through the M3 R on the orexin neurons that directly project to the RVLM.
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Affiliation(s)
- Yu-Wen E Dai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yen-Hsien Lee
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jennifer Y S Chen
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Yen-Kuang Lin
- Biostatistic Center, Taipei Medical University, Taipei, Taiwan
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Lee HJ, Chang LY, Ho YC, Teng SF, Hwang LL, Mackie K, Chiou LC. Stress induces analgesia via orexin 1 receptor-initiated endocannabinoid/CB1 signaling in the mouse periaqueductal gray. Neuropharmacology 2016; 105:577-586. [PMID: 26907809 DOI: 10.1016/j.neuropharm.2016.02.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/01/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
Abstract
The orexin system consists of orexin A/hypocretin 1 and orexin B/hypocretin 2, and OX1 and OX2 receptors. Our previous electrophysiological study showed that orexin A in the rat ventrolateral periaqueductal gray (vlPAG) induced antinociception via an OX1 receptor-initiated and endocannabinoid-mediated disinhibition mechanism. Here, we further characterized antinociceptive effects of orexins in the mouse vlPAG and investigated whether this mechanism in the vlPAG can contribute to stress-induced analgesia (SIA) in mice. Intra-vlPAG (i.pag.) microinjection of orexin A in the mouse vlPAG increased the hot-plate latency. This effect was mimicked by i.pag. injection of WIN 55,212-2, a CB1 agonist, and antagonized by i.pag. injection of the antagonist of OX1 (SB 334867) or CB1 (AM 251), but not OX2 (TCS-OX2-29) or opioid (naloxone), receptors. [Ala(11), D-Leu(15)]-orexin B (i.pag.), an OX2 selective agonist, also induced antinociception in a manner blocked by i.pag. injection of TCS-OX2-29, but not SB 334867 or AM 251. Mice receiving restraint stress for 30 min showed significantly longer hot-plate latency, more c-Fos-expressing orexin neurons in the lateral hypothalamus and higher orexin levels in the vlPAG than unrestrained mice. Restraint SIA in mice was prevented by i.pag. or intraperitoneal injection of SB 334867 or AM 251, but not TCS-OX2-29 or naloxone. These results suggest that during stress, hypothalamic orexin neurons are activated, releasing orexins into the vlPAG to induce analgesia, possibly via the OX1 receptor-initiated, endocannabinoid-mediated disinhibition mechanism previously reported. Although activating either OX1 or OX2 receptors in the vlPAG can lead to antinociception, only OX1 receptor-initiated antinociception is endocannabinoid-dependent.
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Affiliation(s)
- Hsin-Jung Lee
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Lu-Yang Chang
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yu-Cheng Ho
- Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shu-Fang Teng
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ling-Ling Hwang
- Department of Physiology, Taipei Medical University, Taipei, Taiwan
| | - Ken Mackie
- Gill Center and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Lih-Chu Chiou
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan; Research Center for Chinese Medicine & Acupuncture, China Medical University, Taichung, Taiwan.
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15
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Abstract
In current health examination setting, people frequently undergo heart rate variability (HRV) analysis and colonoscopy on the same day. However, it remains unclear whether the bowel preparation before colonoscopy affects HRV. This study aimed to evaluate the association between HRV and bowel preparation.We conducted a cross-sectional observational study of 1755 people from January 2012 to December 2013 in Taipei, Taiwan. The participants, aged 45 to 65 years, received health examinations that included a physical examination, blood tests, and an HRV analysis. Among these people, 1099 additionally received a colonoscopy on the same day and underwent bowel preparation 1 day before the colonoscopy. The association between HRV and bowel preparation was derived by a multivariable linear regression with adjusted confounding factors.Bowel preparation was associated with a lower standard deviation of the normal-to-normal intervals (SDNN), the root mean square of the successive differences (RMSSD), low-frequency power (LF), and high-frequency power (HF) (all P < 0.0001). After adjusting confounding factors, bowel preparation remained correlated with lower SDNN, RMSSD, LF, and HF (all P < 0.0001). Higher serum phosphorus and lower serum potassium levels were noted in the bowel preparation group (P < 0.0001), and an association between lower HRV and higher serum phosphorus and lower serum potassium levels was only noted in the bowel preparation group.Bowel preparation was significantly associated with lower HRV. The underlying mechanism may be related to an electrolyte imbalance. Cautions may be needed when interpreting HRV reports for people receiving bowel preparations before colonoscopy.
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Affiliation(s)
- Shang-Cheng Huang
- From the Department of Family Medicine and Community Health, Tri-Service General Hospital, National Defense Medical Center (SCH, WHF, CCW, WLC, TWK, YWC); Department of Graduate Institute of Medical Sciences College of Medicine, Taipei Medical University (SCH); Department of Physiology College of Medicine, Taipei Medical University (LLH); and School of Public Health, National Defense Medical Center, Taipei, Taiwan (CMC)
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Lee YH, Tsai MC, Li TL, Dai YWE, Huang SC, Hwang LL. Spontaneously hypertensive rats have more orexin neurons in the hypothalamus and enhanced orexinergic input and orexin 2 receptor-associated nitric oxide signalling in the rostral ventrolateral medulla. Exp Physiol 2015; 100:993-1007. [PMID: 26096870 DOI: 10.1113/ep085016] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 06/17/2015] [Indexed: 01/24/2023]
Abstract
NEW FINDINGS What is the central question of this study? Our previous study demonstrates that elevated orexin 2 receptor (OX2R) activity within the rostral ventrolateral medulla (RVLM) contributes to hypertension in spontaneously hypertensive rats (SHRs), and a lower OX2R protein level was detected in their RVLM. The present study aims to explore the mechanisms underlying elevated orexinergic activity in the RVLM of SHRs, compared with their normotensive counterparts, Wistar-Kyoto rats. What is the main finding and its importance? Increased orexinergic input into the RVLM and enhanced OX2R responsiveness in the RVLM, which was mainly mediated by augmented OX2R-neuronal nitric oxide synthase signalling, may underlie the elevated OX2R activity within the RVLM of SHRs. Our previous study showed that elevated orexin 2 receptor (OX2R) activity within the rostral ventrolateral medulla (RVLM) contributes to hypertension in spontaneously hypertensive rats (SHRs). Herein, we investigated the mechanism(s) underlying the elevated OX2R activity. The following results were found. (i) More hypothalamic orexin A-immunoreactive (OXA-IR) cells existed in SHRs than in Wistar-Kyoto (WKY) rats at either 4 (2217 ± 43 versus 1809 ± 69) or 16 weeks of age (1829 ± 59 versus 1230 ± 84). The number of OXA-IR cells that project to the RVLM was higher in 16-week-old SHRs than in WKY rats (91 ± 11 versus 52 ± 11). (ii) Higher numbers of OXA-IR and RVLM-projecting OXA-IR cells were found in the dorsomedial and perifornical hypothalamus of 16-week-old SHRs. (iii) Spontaneously hypertensive rats had higher levels of orexin A and B in the hypothalamus and higher levels of orexin A in the RVLM than did WKY rats. (iv) Unilateral intra-RVLM application of OX2R agonist, orexin A or [Ala(11), d-Leu(15)]-orexin B (50 pmol) induced a larger pressor response in SHRs than in WKY rats. (v) Intra-RVLM pretreatment with a neuronal nitric oxide synthase (NOS) inhibitor, 7-nitro-indazole (2.5 pmol), or a soluble guanylate cyclase inhibitor, methylene blue (250 pmol), reduced the intra-RVLM [Ala(11), d-Leu(15) ]-orexin B-induced pressor response in both WKY rats and SHRs. In contrast, an inducible NOS inhibitor, aminoguanidine (100 pmol), was ineffective. (vi) Neuronal NOS was co-expressed with OX2R in RVLM neurons. In conclusion, increased orexinergic input and enhanced OX2R-neuronal NOS signalling may underlie elevated OX2R activity in the RVLM and contribute to the pathophysiology of hypertension in SHRs.
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Affiliation(s)
- Yen-Hsien Lee
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Min-Chien Tsai
- Department of Physiology and Biophysics, Graduate Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Tzu-Ling Li
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Wen E Dai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shang-Cheng Huang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Liu SW, Liu YL, Hwang LL, Wang SC, Kuo HW, Wu SL, Dai YWE, Liu SC, Ho IK, Chen ACH, Hsiao CF, Tsou HH. Chemokine IP-10 is correlated with cardiac responses and status of infection with HIV and HCV in methadone maintenance patients. Int J Cardiol 2015; 194:36-8. [PMID: 26011262 DOI: 10.1016/j.ijcard.2015.05.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 05/09/2015] [Indexed: 10/23/2022]
Affiliation(s)
- Sheng-Wen Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Yu-Li Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan.
| | - Ling-Ling Hwang
- Graduate Institute of Medical Sciences and Department of Physiology, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan
| | - Sheng-Chang Wang
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Hsiang-Wei Kuo
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Shiow-Ling Wu
- Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan
| | - Yu-Wen E Dai
- Graduate Institute of Medical Sciences and Department of Physiology, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan
| | - Shu Chih Liu
- Center for Neuropsychiatric Research, National Health Research Institutes, Miaoli, Taiwan
| | - Ing-Kang Ho
- Center for Drug Abuse and Addiction, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
| | - Andrew C H Chen
- Department of Psychiatry, The Zucker Hillside Hospital, North Shore-Long Island Jewish Medical Center Health System, Glen Oaks, NY, USA; The Feinstein Institute for Medical Research, Hofstra North Shore-LIJ School of Medicine at Hofstra University, Manhasset, NY, USA
| | - Chin-Fu Hsiao
- Division of Clinical Trial Statistics, Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan
| | - Hsiao-Hui Tsou
- Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan; Graduate Institute of Biostatistics, College of Public Health, China Medical University, Taichung, Taiwan.
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Lee YH, Dai YWE, Huang SC, Li TL, Hwang LL. Blockade of central orexin 2 receptors reduces arterial pressure in spontaneously hypertensive rats. Exp Physiol 2013; 98:1145-55. [DOI: 10.1113/expphysiol.2013.072298] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Chang CC, Lee PS, Chou Y, Hwang LL, Juan SH. Mediating effects of aryl-hydrocarbon receptor and RhoA in altering brain vascular integrity: the therapeutic potential of statins. Am J Pathol 2012; 181:211-21. [PMID: 22720799 DOI: 10.1016/j.ajpath.2012.03.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 03/14/2012] [Accepted: 03/19/2012] [Indexed: 12/13/2022]
Abstract
We have demonstrated previously that focal adhesion kinase (FAK)/RhoA alteration by the aryl-hydrocarbon receptor (AhR) agonist 3-methylcholanthrene (3MC) is involved in the antimigratory effects of 3MC in human umbilical vascular endothelial cells. Here, we identified that signaling properties and molecular mechanisms of RhoA/β-catenin were both implicated in alterations to blood-brain barrier integrity. The mechanisms of action were the down-regulation of integrin, the extracellular matrix, and adherens junction stability. PTEN phosphorylation by 3MC-mediated AhR/RhoA activation increased the proteasomal degradation of β-catenin through PKCδ/pGSK3β-mediated β-catenin phosphorylation; the crucial roles of AhR/RhoA in this process were verified by using gain- or loss-of-function experiments. The decrease in β-catenin led to decreased expression of fibronectin and α5β1 integrin. Additionally, protein interactions among FAK, VE-cadherin, vinculin, and β-actin were simultaneously decreased, resulting in adherens junction instability. Novel functional TCF/LEF1 binding sites in the promoter regions of fibronectin and α5/β1 integrin were identified by electrophoretic mobility shift and chromatin immunoprecipitation assays. The results indicate that the binding activities of β-catenin decreased in mouse cerebrovascular endothelial cells treated with 3MC. In addition, simvastatin and pravastatin treatment reversed 3MC-mediated alterations in mouse cerebrovascular endothelial cells by RhoA inactivation, and the in vitro findings were substantiated by an in vivo blood-brain barrier assay. Thus, endothelial barrier dysfunction due to 3MC occurs through AhR/RhoA-mediated β-catenin down-regulation, which is reversed by simvastatin treatment in vivo.
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Affiliation(s)
- Chih-Cheng Chang
- Graduate Institute of Medical Sciences, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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20
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Tuan TF, Chung CT, Tsou HH, Chen FW, Lin HL, Lai YK, Lee WS, Chao YS, Hwang LL, Chen CT. Putative tumor metastasis-associated genes in human gastric cancer. Int J Oncol 2012; 41:1068-84. [PMID: 22664961 DOI: 10.3892/ijo.2012.1502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 05/11/2012] [Indexed: 01/06/2023] Open
Abstract
Gastric cancer is one of the leading causes of cancer mortality and its malignancy, resulting from disseminated cancer cells of diffuse type, is clinically manifested as metastases to the liver and peritoneum. The aim of the present study was to identify putative tumor metastasis-associated genes in human gastric cancer cells of diffuse type. An MKN45 cell line constitutively expressing green fluorescent protein (MKN45-GFP) was established and selected using the Transwell® system for invasive sublines MKN45-GFP-4, MKN45-GFP-10 and MKN45-GFP-12. MKN45-GFP-10 and MKN45-GFP-12 are highly invasive compared to the others. The mRNA levels were measured with cDNA microarrays and correlated with their invasion abilities in these sublines. Many of the genes identified with a positive or negative correlation are associated with angiogenesis, cell cycle, cytoskeleton and cell motility, protease and cell adhesion, as well as cellular signal transduction. In particular, novel genes without known functions were also noted. RT-PCR and western blot analyses were applied to verify the expression of selective genes. Following orthotopical intraperitoneal implantation, MKN45-GFP-12 demonstrated significantly higher in vivo tumor malignancies than parental MKN45-GFP in ascites induction and liver -invasion in mice. We have identified putative gastric tumor metastasis-associated, as well as novel genes. These genes and their protein products are to be further explored for their functional roles associated with tumor metastasis. The molecular profiles of these identified genes, gene transcripts and proteins in the patient specimens are likely to be useful biomarkers for diagnostic, therapeutic and/or prognostics. Most importantly, they may be used as molecular targets for the discovery of antitumor drugs against human gastric cancer metastasis.
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Affiliation(s)
- Tsung-Fan Tuan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan, R.O.C
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Kuo MY, Ou HC, Lee WJ, Kuo WW, Hwang LL, Song TY, Huang CY, Chiu TH, Tsai KL, Tsai CS, Sheu WHH. Ellagic acid inhibits oxidized low-density lipoprotein (OxLDL)-induced metalloproteinase (MMP) expression by modulating the protein kinase C-α/extracellular signal-regulated kinase/peroxisome proliferator-activated receptor γ/nuclear factor-κB (PKC-α/ERK/PPAR-γ/NF-κB) signaling pathway in endothelial cells. J Agric Food Chem 2011; 59:5100-5108. [PMID: 21480623 DOI: 10.1021/jf1041867] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Previous studies have shown that vascular endothelium-derived matrix metalloproteinases (MMPs) contribute to the destabilization of atherosclerotic plaques, a key event triggering acute myocardial infarction. In addition, studies have reported that the PKC-MEK-PPARγ signaling pathway is involved in oxidized low-density lipoprotein (oxLDL)-induced expression of MMPs. Ellagic acid, a phenolic compound found in fruits and nuts, has potent antioxidant, anti-inflammatory, and anticancerous properties. However, the molecular mechanisms underlying its antiatherogenic effects remain to be clarified. This study aimed to assess whether the effects of ellagic acid on the fibrotic markers MMP-1 and MMP-3 are modulated by the PKC-ERK-PPAR-γ signaling pathway in human umbilical vein endothelial cells (HUVECs) that have been exposed to oxLDL. It was found that ellagic acid significantly inhibited oxLDL-induced expressions of MMP-1 and MMP-3. Pretreatment with ellagic acid and DPI, a well-known ROS inhibitor, attenuated the oxLDL-induced expression and activity of PKC-α. In addition, ellagic acid as well as pharmacological inhibitors of ROS, calcium, and PKC strongly suppressed the oxLDL-induced phosphorylation of extracellular signal-regulated kinase (ERK) and NF-κB activation. Moreover, ellagic acid ameliorated the oxLDL-induced suppression of PPAR-γ expression. In conclusion, the data suggest that ellagic acid elicits its protective effects by modulating the PKC-α/ERK/PPAR-γ/NF-κB pathway, resulting in the suppression of ROS generation and, ultimately, inhibition of MMP-1 and MMP-3 expression in HUVECs exposed to oxLDL.
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Affiliation(s)
- Mei-Ying Kuo
- Department of Physical Therapy and Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan
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Hu CB, Chen CP, Yeh TK, Song JS, Chang CY, Chuu JJ, Tung FF, Ho PY, Chen TW, Lin CH, Wang MH, Chang KY, Huang CL, Lin HL, Li WT, Hwang DR, Chern JH, Hwang LL, Chang JY, Chao YS, Chen CT. BPR0C261 is a novel orally active antitumor agent with antimitotic and anti-angiogenic activities. Cancer Sci 2010; 102:182-91. [DOI: 10.1111/j.1349-7006.2010.01744.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Chen CP, Hu CB, Yeh KC, Song JS, Yeh TK, Tung FF, Hwang LL, Tseng HY, Huang YC, Shy HS, Hsieh SH, Shen CC, Wang HS, Hsieh HP, Liou JP, Chao YS, Chen CT. Antiangiogenic activities and cisplatin-combined antitumor activities of BPR0L075. Anticancer Res 2010; 30:2813-2822. [PMID: 20683017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND Antimitotic tubulin-binding BPR0L075 is structurally analogous to the vascular-disrupting combretastatin A-4. MATERIALS AND METHODS In vitro/in vivo models of endothelial cells cultures, Matrigel plug assay, tumor-bearing nude mice, and murine leukemia cells-inoculated mice were utilized to evaluate BPR0L075 for antiangiogenic and antitumoral activity spectra. RESULTS BPR0L075 concentration-dependently inhibited proliferation and migration of human umbilical vein endothelial cells (HUVECs), disrupted capillary tube formations of HUVECs and rat aorta endothelial cells, and suppressed in vivo VEGF-mediated angiogenesis in Matrigel plugs in mice. Besides inhibiting the colony growth of cancer cells, BPR0L075 suppressed growth of subcutaneously-xenografted human lung, colorectal, and cervical solid tumors in nude mice. Combination treatments of BPR0L075 plus cisplatin, compared to either agent alone, demonstrated a stronger growth inhibition against the tumor xenografts in nude mice and longer lifespan in the leukemia mice. CONCLUSION BPR0L075 is an antitumoral and antiangiogenic agent and potentiates the anticancer activity of cisplatin.
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Affiliation(s)
- Ching-Ping Chen
- Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli 35053, Taiwan, R.O.C
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Huang SC, Dai YWE, Lee YH, Chiou LC, Hwang LL. Orexins depolarize rostral ventrolateral medulla neurons and increase arterial pressure and heart rate in rats mainly via orexin 2 receptors. J Pharmacol Exp Ther 2010; 334:522-9. [PMID: 20494957 DOI: 10.1124/jpet.110.167791] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An injection of orexin A or B into the cisterna magna or the rostral ventrolateral medulla (RVLM), where bulbospinal vasomotor neurons are located, elevated arterial pressure (AP) and heart rate (HR). We examined how orexins affected RVLM neurons to regulate cardiovascular functions by using in vitro recordings of neuronal activity of the RVLM and in vivo measurement of cardiovascular functions in rats. Orexin A and B concentration-dependently depolarized RVLM neurons. At 100 nM, both peptides excited 42% of RVLM neurons. Tetrodotoxin failed to block orexin-induced depolarization. In the presence of N-(2-methyl-6-benzoxazolyl)-N'-1, 5-naphthyridin-4-yl urea (SB-334867), an orexin 1 receptor (OX(1)R) antagonist, orexin A depolarized 42% of RVLM neurons with a smaller, but not significantly different, amplitude (4.9 +/- 0.8 versus 7.2 +/- 1.1 mV). In the presence of (2S)-1- (3,4-dihydro-6,7-dimethoxy-2(1H)-isoquinolinyl)-3,3-dimethyl-2-[(4-pyridinylmethyl)amino]-1-butanone hydrochloride (TCS OX2 29), an orexin 2 receptor (OX(2)R) antagonist, orexin A depolarized 25% of RVLM neurons with a significantly smaller amplitude (1.7 +/- 0.5 mV). Coapplication of both antagonists completely eliminated orexin A-induced depolarization. An OX(2)R agonist, [Ala(11),D-Leu(15)]-orexin B, concentration-dependently depolarized RVLM neurons. Regarding neuronal phenotypes, orexins depolarized 88% of adrenergic, 43% of nonadrenergic, and 36 to 41% of rhythmically firing RVLM neurons. Intracisternal TCS OX2 29 (3 and 10 nmol) suppressed intracisternal orexin A-induced increases of AP and HR, whereas intracisternal SB-334867 (3 and 10 nmol) had no effect on the orexin A-induced increase of HR but suppressed the orexin A-induced pressor response at 10 nmol. We concluded that orexins directly excite RVLM neurons, which include bulbospinal vasomotor neurons, and regulate cardiovascular function mainly via the OX(2)R, with a smaller contribution from the OX(1)R.
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Affiliation(s)
- Shang-Cheng Huang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Hwang LL, Wang CH, Li TL, Chang SD, Lin LC, Chen CP, Chen CT, Liang KC, Ho IK, Yang WS, Chiou LC. Sex differences in high-fat diet-induced obesity, metabolic alterations and learning, and synaptic plasticity deficits in mice. Obesity (Silver Spring) 2010; 18:463-9. [PMID: 19730425 DOI: 10.1038/oby.2009.273] [Citation(s) in RCA: 292] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Obesity is a potential risk factor for cognitive deficits in the elder humans. Using a high-fat diet (HFD)-induced obese mouse model, we investigated the impacts of HFD on obesity, metabolic and stress hormones, learning performance, and hippocampal synaptic plasticity. Both male and female C57BL/6J mice fed with HFD (3 weeks to 9-12 months) gained significantly more weights than the sex-specific control groups. Compared with the obese female mice, the obese males had similar energy intake but developed more weight gains. The obese male mice developed hyperglycemia, hyperinsulinemia, hypercholesterolemia, and hyperleptinemia, but not hypertriglyceridemia. The obese females had less hyperinsulinemia and hypercholesterolemia than the obese males, and no hyperglycemia and hypertriglyceridemia. In the contextual fear conditioning and step-down passive avoidance tasks, the obese male, but not female, mice showed poorer learning performance than their normal counterparts. These learning deficits were not due to sensorimotor impairment as verified by the open-field and hot-plate tests. Although, basal synaptic transmission characteristics (input-output transfer and paired-pulse facilitation (PPF) ratio) were not significantly different between normal and HFD groups, the magnitudes of synaptic plasticity (long-term potentiation (LTP) and long-term depression (LTD)) were lower at the Schaffer collateral-CA1 synapses of the hippocampal slices isolated from the obese male, but not female, mice, as compared with their sex-specific controls. Our results suggest that male mice are more vulnerable than the females to the impacts of HFD on weight gains, metabolic alterations and deficits of learning, and hippocampal synaptic plasticity.
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Affiliation(s)
- Ling-Ling Hwang
- Department of Physiology, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Tuan TF, Tsai ML, Yeh KC, Huang HC, Chung CT, Huang CL, Han CH, Chen CP, Wang MH, Shen CC, Lai YK, Lee WS, Hwang LL, Chen CT. Intravenous paclitaxel against metastasis of human gastric tumors of diffuse type. Cancer Chemother Pharmacol 2010; 66:773-83. [PMID: 20044750 DOI: 10.1007/s00280-009-1222-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 12/13/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE Gastric cancer is one of the leading cancerous diseases worldwide. It is diagnosed often at the advanced stage for which chemotherapy is the main treatment option. The prognosis remains poor for metastatic, especially the diffuse type, gastric cancers. We investigated the efficacy of intravenously administered paclitaxel treating metastases of locally disseminated gastric tumors of diffuse type. METHODS Transfection of green fluorescent proteins (GFP)-expressing plasmid into human gastric cancer MKN45 cells of diffuse type was performed, and MKN45-GFP cells constitutively expressing GFP were isolated. The MKN45-GFP cells were orthotopically inoculated into the mouse peritoneal cavity, and tumor growth and organ metastases were monitored. Liver metastases were harvested, re-inoculated, monitored for liver metastases again, and harvested for further inoculation. This in vivo selection procedure was repeated to isolate a subline with high metastatic abilities demonstrated by in vitro invasion abilities using Transwell((R)) system. By visualizing the GFP-expressing tumors, the effects of intravenously administered paclitaxel against the growing peritoneally disseminated and metastasized tumors in nude mice without laparotomy were measured. RESULTS An in vivo selected gastric cancer cell line MKN45-GFP-ip4 with high metastatic ability was established. Its invasion ability was inhibited by paclitaxel treatments in vitro. The growths of metastatic and intraperitoneally disseminated MKN45-GFP-ip4 tumors were significantly suppressed by intravenous paclitaxel treatments in nude mice. CONCLUSIONS We found that intravenous paclitaxel is active against the metastases of human gastric cancer of peritoneal diffuse type, which warrants further investigations on optimizing the perioperative regimens with intravenous paclitaxel therapy for gastric cancer in patients.
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Affiliation(s)
- Tsung-Fan Tuan
- Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli, Taiwan
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Li TL, Chiou LC, Lin YS, Hsieh JR, Hwang LL. Electrophysiological study on the effects of leptin in rat dorsal motor nucleus of the vagus. Am J Physiol Regul Integr Comp Physiol 2007; 292:R2136-43. [PMID: 17303683 DOI: 10.1152/ajpregu.00563.2006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Immunoreactivity of leptin receptor (Ob-R) has been detected in rat dorsal motor nucleus of the vagus (DMNV). Here, we confirmed the presence of Ob-R immunoreactivity on retrograde-labeled parasympathetic preganglionic neurons in the DMNV of neonatal rats. The present study investigated the effects of leptin on DMNV neurons, including parasympathetic preganglionic neurons, by using whole cell patch-clamp recording technique in brain stem slices of neonatal rats. Leptin (30-300 nM) induced membrane depolarization and hyperpolarization, respectively, in 14 and 15 out of 80 DMNV neurons tested. Both leptin-induced inward and outward currents persisted in the presence of TTX, indicating that leptin affected DNMV neurons postsynaptically. The current-voltage (I-V) curve of leptin-induced inward currents is characterized by negative slope conductance and has an average reversal potential of -90 +/- 3 mV. The reversal potential of the leptin-induced inward current was shifted to a more positive potential level in a high-potassium medium. These results indicate that a decrease in potassium conductance is likely the main ionic mechanism underlying the leptin-induced depolarization. On the other hand, the I-V curve of leptin-induced outward currents is characterized by positive slope conductance and has an average reversal potential of -88 +/- 3 mV, suggesting that an increase in potassium conductance may underlie leptin-induced hyperpolarization. Most of the leptin-responsive DMNV neurons were identified as being parasympathetic preganglionic neurons. These results suggest that the DMNV is one of the central target sites of leptin, and leptin can regulate parasympathetic outflow from the DMNV by directly acting on the parasympathetic preganglionic neurons of the DMNV.
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Affiliation(s)
- Tzu-Ling Li
- Department of Physiology, College of Medicine, Taipei Medical University, Taipei, Taiwan
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28
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Abstract
Interrelationships between energy homeostasis and regulation of cardiovascular functions have been suggested by previous observations [Am. J. Physiol. 278 (2000) R692; Regul. Pept. 104 (2002) 75; Am. J. Physiol. 277 (1999) R1780]. Cocaine- and amphetamine-regulated transcript (CART) was first discovered in the striatum of rats treated with cocaine or amphetamine. The CART peptides were later found in the hypothalamus and functioned as anorectic peptides. We observed that intracisternally (I.C.) administered CART peptide fragments (CART 61-102 and CART 55-102) dose-dependently (1-4 nmol) increased heart rate and blood pressure in urethane-anesthetized adult male Sprague-Dawley rats. Intrathecal (levels T2-T3) and intravenous administrations of these peptides, however, showed little or no effects on the heart rate and blood pressure in the rat. Furthermore, an increase of c-Fos-like immunoreactivity in the rat rostral ventrolateral medulla (RVLM) following an I.C. CART 61-102 was observed. The results suggest that central pressor effects of anorectic CART peptides may involve in activation of the medullary sympathetic systems in the rat. Our observations support the hypothesis that energy homeostasis and cardiovascular regulations are closely related and regulated.
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Affiliation(s)
- Ling-Ling Hwang
- Department of Physiology, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan.
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Abstract
Angiogenesis plays a major role in many physiological and pathological processes. Pathological development of diseased conditions like growth and metastasis of solid tumors and psoriasis is associated with angiogenesis. Assays developed, thus far, for evaluation of angiogenesis activity are qualitative or semiquantitative. In vivo angiogenesis assays are more physiologically relevant than in vitro models and, however, time-consuming, labor-intensive, and expensive. The ex vivo rat aorta tube formation model has been demonstrated to correlate well to the physiological conditions. The present study established a reproducible and quantitative assay for evaluating angiogenesis with rat aorta ring cultures. Rat thoracic aortas were harvested, cross-sectioned into rings of 1-mm thickness using a set of aligned blades, and cultured in a three-dimensional extracellular matrix. Endothelial cells outgrow consistently from the aorta rings cultured in endothelial cell growth medium. Angiogenic activity was quantified by a colorimetric 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2H-tetrazolium/phenazine methosulfate method. The colorimetric assay was reproducible, and its results were compared in parallel with that of the imaging analysis method. IC(50) values of several known antiangiogenics, SU5416, suramin, paclitaxel, and 2-methoxyestradiol, were determined and were comparable to those obtained using the imaging analysis method. We have established a simple, reproducible, and quantitative assay for evaluation of angiogenesis activity with the cultured rat aorta ring, which can be used to screen for angiogenics and angiostatics.
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Affiliation(s)
- Hsin-Sheng Wang
- Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Taipei, Taiwan, ROC
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Abstract
Orexin A and B (hypocretin 1 and 2) are the endogenous ligands of orexin receptors, a G-protein-coupled orphan receptor family containing orexin 1 (OX1) and orexin 2 (OX2) types. Orexin A induces analgesia in acute and inflammatory pain models. We further elucidated the possible antiallodynic effect of intrathecal orexins in a rat model of postoperative pain. Mechanical allodynia was induced by incising the rat hind paw and evaluated with the withdrawal threshold to von Frey filament stimulation. Intrathecal orexin A (0.03-1 nmol) and orexin B (0.1-3 nmol) dose dependently attenuated the incision-induced allodynia. Orexin A (ED50 = 0.06 nmol) is more potent than orexin B. The effects of orexin A and B were abolished by their respective antibodies, but not by naloxone, and were attenuated by suramin and strychnine, the P2X purinergic and glycine receptor antagonists, respectively. SB-334867, an OX1 receptor antagonist, at 30 nmol completely blocked the effect of orexin A but, even at 100 nmol, only partially antagonized the effect of orexin B. Orexin A antibody, SB-334867, suramin, strychnine, or naloxone enhanced the incision-induced allodynic response. It is concluded that intrathecal orexins reduce incision-induced allodynia through OX1 receptors. Glycine and P2X purinergic receptors, but not opioid receptors, might be involved in the antiallodynic effects of orexins. Endogenous orexin might be released after incision injury to activate the spinal OX1 receptors as an endogenous analgesic protector.
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Affiliation(s)
- Jen-Kun Cheng
- Department of Pharmacology, College of Medicine, National Taiwan University, 1, Jen-Ai Rd., Section 1, Taipei 100, Taiwan
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Abstract
1. Whole-cell patch recordings were made from antidromically identified sympathetic preganglionic neurons (SPN) of immature rat spinal cord slices. Bath application of nociceptin (0.1-1 micromol/L) suppressed excitatory postsynaptic potentials (EPSP) and hyperpolarized a population of SPN; these effects were naloxone (1 micromol/L) insensitive. 2. Nociceptin suppressed the amplitude of EPSP without causing a concomitant change in glutamate-induced depolarizations, suggesting a presynaptic inhibitory action. 3. Analysis of current-voltage relationships showed that nociceptin hyperpolarized SPN by increasing an inwardly rectifying K+ current. 4. Intrathecal injection of nociceptin (3, 10 and 30 nmol) to urethane-anaesthetized rats dose-dependently reduced the mean arterial pressure and heart rate; these effects were not prevented by prior intravenous injection of naloxone (1 mg/kg). 5. Results from our in vitro and in vivo experiments suggest that nociceptin suppresses spinal sympathetic outflow either by attenuating excitatory synaptic responses or hyperpolarizing SPN.
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Affiliation(s)
- G C Brailoiu
- Department of Pharmacology, James H Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614, USA
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Abstract
1. Whole-cell patch-clamp recordings were made from neurones of the dorsal motor nucleus of the vagus (DMNV), including Fluoro-gold-labelled parasympathetic preganglionic neurones (PPNs), in slices of the rat medulla. In the latter case, rats had received an I.P. injection of Fluoro-gold solution (10 microg) 2-3 days earlier. 2. Superfusion of orexin A or B (10-300 nM) caused a slow depolarization in approximately 30% of the DMNV neurones, including PPNs. Orexin-induced depolarizations, which persisted in TTX (0.5 microM)-containing Krebs solution, were reduced by 70% in a low-Na+ (26 mM) Krebs solution, indicating the involvement of Na+ ions. A significant change in orexin-induced depolarizations was not obtained in either a high-K+ (7 mM) or Cd2+ (100 microM) Krebs solution. 3. Inclusion of the hydrolysis-resistant guanine nucleotide GDP-beta-S in the patch solution significantly reduced the orexin A- or B-induced depolarizations. 4. Under whole-cell voltage-clamp conditions, the orexin-induced inward current declined with hyperpolarization, but did not reverse polarity in the potential range between -120 and 0 mV. In low-Na+ solution, the orexin-induced current was reduced, and the I-V curve reversed polarity at about -105 mV; the response was further reduced and the reversal potential shifted to -90 mV in a low-Na+, high-K+ Krebs solution. 5. It is concluded that the peptides orexin A and B, acting on orexin receptors, which are GTP-binding-protein coupled, are excitatory to DMNV neurones. In addition, more than one conductance, which may include a non-selective cation conductance and a K+ conductance, appears to be involved in the orexin-induced depolarization.
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Affiliation(s)
- L L Hwang
- Department of Pharmacology, James H. Quillen College of Medicine, East Tennessee State University, PO Box 70577, Johnson City, TN 37614, USA
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Abstract
Orexin A and B, also known as hypocretin 1 and 2, are two recently isolated hypothalamic peptides. As orexin-containing neurons are strategically located in the lateral hypothalamus, which has long been suspected to play an important role in feeding behaviors, initial studies were focused on the involvement of orexins in positive food intake and energy metabolism. Recent studies implicate a more diverse biological role of orexins, which can be manifested at different level of the neuraxis. For example, canine narcolepsy, a disorder with close phenotypic similarity to human narcolepsy, is caused by a mutation of hypocretin receptor 2 gene. Results from our immunohistochemical and functional studies, which will be summarized here, suggest that the peptide acting on neurons in the rostral ventrolateral medulla augment sympathoexcitatory outflow to the spinal cord. This finding is discussed in the context of increased sympathetic activity frequently associated with obesity.
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Affiliation(s)
- N J Dun
- Department of Pharmacology, James H. Quillen College of Medicine, East Tennessee State University, P.O. Box 70577, Johnson City, TN 37614, USA.
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Chen CT, Hwang LL, Chang JK, Dun NJ. Pressor effects of orexins injected intracisternally and to rostral ventrolateral medulla of anesthetized rats. Am J Physiol Regul Integr Comp Physiol 2000; 278:R692-7. [PMID: 10712290 DOI: 10.1152/ajpregu.2000.278.3.r692] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Orexin A and B, two recently isolated hypothalamic peptides, have been reported to increase food consumption upon intracerebroventricular injections in rats. In addition to the hypothalamus, orexin A-immunoreactive fibers have been observed in several areas of the medulla that are associated with cardiovascular functions. The present study was undertaken to evaluate the hypothesis that orexins may influence cardiovascular response by interacting with neurons in the medulla. Intracisternal injections of orexins A (0.0056-7.0 nmol) or B (0.028-0.28 nmol) dose dependently increased mean arterial pressure (MAP) by 4-27 mmHg and heart rate (HR) by 26-80 beats/min in urethan-anesthetized rats, with orexin A being more effective in this regard. MAP and HR were not changed by intravenous injection of orexins at higher concentrations. Microinjection of orexin A (14 pmol/50.6 nl) to the rostral ventrolateral medulla, which was confirmed by histological examination, increased MAP and HR. Our results indicate that, in addition to a role in positive feeding behavior, orexins may enhance cardiovascular response via an action on medullary neurons.
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Affiliation(s)
- C T Chen
- Department of Pharmacology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614, USA
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Abstract
Patch-clamp recordings in whole-cell configuration were made from ventrolateral medulla neurons of brainstem slices from 8-12-day-old rats. 5-Hydroxytryptamine (3-30 microM) concentration-dependently suppressed excitatory and inhibitory postsynaptic currents evoked by focal stimulation. An augmentation of inhibitory synaptic currents by 5-hydroxytryptamine was noted in a small number of neurons. 5-Hydroxytryptamine depressed synaptic currents with or without causing a significant change in holding currents and membrane conductances; the inward or outward currents induced by exogenously applied glutamate or GABA/glycine were also not significantly changed by 5-hydroxytryptamine. In paired-pulse paradigms designed to evaluate a presynaptic site of action, 5-hydroxytryptamine suppressed synaptic currents but enhanced the paired-pulse facilitation. 5-Hydroxytryptamine reduced the frequency of miniature excitatory postsynaptic currents without significantly affecting the amplitude. 5-Carboxamidotryptamine, 8-hydroxy-2(di-n-propylamino)tetralin, sumatriptan and N-(3-trifluoromethylphenyl)piperazine which exhibit 5-hydroxytryptamine1 receptor agonist activity, depressed synaptic currents with different potencies, with 5-carboxamidotryptamine being the most potent. The non-selective 5-hydroxytryptamine1 receptor antagonist pindolol attenuated the presynaptic effect of 5-hydroxytryptamine, whereas the 5-hydroxytryptamine1A antagonist pindobind-5-hydroxytryptamine1A and 5-hydroxytryptamine2 receptor antagonist ketanserin were ineffective. Our results indicate that 5-hydroxytryptamine suppressed synaptic transmission in ventrolateral medulla neurons by activating presynaptic 5-hydroxytryptamine1 receptors, probably the 5-hydroxytryptamine1B/5-hydroxytryptamine1D subtype. In addition, 5-hydroxytryptamine augmented inhibitory synaptic currents in a small number of neurons the site and mechanism of this potentiating action are not known.
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Affiliation(s)
- L L Hwang
- Department of Pharmacology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City 37614, USA
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Abstract
1. Whole-cell patch-clamp recordings were made from rostral ventrolateral medulla (RVLM) neurones of brainstem slices from 8- to 12-day-old rats. In the presence of tetrodotoxin (0.5 microM), 5-HT (50 microM) elicited an outward current (I5-HT,outward) (10/44 neurones) associated with an increase in membrane conductance, and an inward current (I5-HT,inward) (29/44 neurones) accompanied by a decrease or no significant change in membrane conductance. 2. The steady-state I-V relationship of I5-HT,outward showed an inward rectification; the 5-HT-induced current, which reversed at -87.9 +/- 3.0 mV, was suppressed by 0.1 mM Ba2+. 3. Two types of steady-state I-V relationship for I5-HT,inward were noted: type I I5-HT,inward was characterized by a significant decrease in membrane conductance and reversed at a potential close to or negative to the theoretical K+ equilibrium potential (EK), -94 mV, in 8/17 neurones; type II I5-HT,inward was not associated with a significant change in membrane conductance and was relatively independent of membrane potential. 4. Both type I and type II I5-HT,inward were significantly reduced in a low [Na+]o solution. In this solution, I5-HT,inward decreased with hyperpolarization and had a linear steady-state I-V relationship with a reversal potential of approximately -110 mV. The reversal potential of type I I5-HT,inward shifted to about -80 mV as the [K+]o was increased from 3.1 to 7.0 mM in low [Na+]o solution. The type II I5-HT,inward did not reverse at the estimated EK in the same solution. 5. While not affected by externally applied Cs+ (1 mM), I5-HT,inward was significantly smaller in RVLM neurones patched with Cs+-containing electrodes; the current reversed at -11.9 +/- 6.4 mV in 8/15 responsive neurones. 6. It may be concluded that in rat RVLM neurones 5-HT increases an inwardly rectifying K+ conductance which may underlie the I5-HT, outward and that a combination of varying degrees of K+ conductance decrease and a Cs+-insensitive, non-selective cation conductance increase may account for the two types of conductance change associated with I5-HT,inward.
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Affiliation(s)
- L L Hwang
- Department of Anatomy & Neurobiology, Medical College of Ohio, 3000 Arlington Avenue, Toledo, OH 43699, USA
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Abstract
Whole cell patch recordings were made from rostral ventrolateral medullar (RVLM) neurons of brain-stem slices from 8- to 12-day-old rats. By superfusion or pressure ejection to RVLM neurons, 5-hydroxytryptamine (5-HT) elicited three types of membrane potential changes: a slow hyperpolarization (5-HTH), a slow depolarization (5-HTD) and a biphasic response, which persisted in a tetrodotoxin (TTX, 0.3 microM)-containing solution. 5-HTH were accompanied by a decrease of input resistance in the majority of responsive neurons. Hyperpolarization reduced and depolarization increased the 5-HTH; the mean reversal potential was -92.3 mV in 3.1 mM and shifted to -69.3 mV in 7 mM [K+]o. Barium (Ba2+, 0.1 mM) but not tetraethylammonium (TEA, 10 mM) suppressed 5-HTH. The 5-HT1A receptor agonist (+/-)-8-hydroxy-dipropylamino-tetralin (8-OH-DPAT; 5-50 microM) hyperpolarized RVLM neurons. The 5-HT1A antagonist pindobind-5-HT1A (PBD; 1-3 microM) and the 5-HT2/5-HT1 receptor antagonist spiperone (1-10 microM) suppressed 5-HTH and the hyperpolarizing phase of biphasic responses; the 5-HT2 receptor antagonist ketanserin (3 microM) was without significant effect. 5-HTD were associated with an increase or no apparent change of input resistance in RVLM neurons. Hyperpolarization of the membrane decreased or caused no apparent change in 5-HTD. 5-HTD were reduced in an elevated [K+]o (7.0 mM) solution and > 60% in a low Na+ (26 mM) solution and were not significantly changed in a low Cl- (6.7 mM) or Ca(2+)-free/high Mg2+ (10.9 mM) solution. The 5-HT2 receptor agonist alpha-methyl-5-HT (50 microM) depolarized RVLM neurons, and the 5-HT2 antagonist ketanserin (1-10 microM) attenuated the 5-HTD and the depolarizing phase of biphasic responses, whereas the 5-HT1A receptor antagonist PBD (2 microM) was without effect. Inclusion of the hydrolysis resistant guanine nucleotide GDP-beta-S in patch solution significantly reduced the 5-HTH as well as the 5-HTD. The present study shows that, in the immature rat RVLM neurons, 5-HT causes a slow hyperpolarization and depolarization probably by interacting with 5-HT1A and 5-HT2 receptors, which are G-proteins coupled. 5-HTH may involve an increase of an inwardly rectifying K+ conductance, and 5-HTD appear to be caused by a decrease of K+ conductance and/or increase of nonselective cation conductance.
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Affiliation(s)
- L L Hwang
- Department of Anatomy and Neurobiology, Medical College of Ohio, Toledo 43614, USA
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Abstract
Immunohistochemical techniques were used to localize nociceptin-like immunoreactivity (NOCI-LI) in the rat spinal cords. NOCI-LI nerve fibers were distributed in three fairly well-define regions: superficial layers of the dorsal horn, central canal area, and intermediolateral cell column (ILp) of lower cervical, thoracic, upper lumbar, and sacral segments of the spinal cord. A few NOCI-LI somata of small diameter were noted in the dorsal horn; NOCI-LI cell bodies were infrequently observed in the ILp or ventral horn. Concentration of NOCI-LI in nerve fibers of the superficial layers and in fibers projecting into the spinal sympathetic and parasympathetic nuclei suggests that the peptide may participate in sensory as well as autonomic functions.
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Affiliation(s)
- N J Dun
- Department of Anatomy and Neurobiology, Medical College of Ohio, Toledo 43615, USA
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Abstract
Distribution of secretoneurin-like immunoreactivity (SN-LI) was studied in the rat sympathetic ganglia/adrenal gland, enteric and sensory ganglia by immunohistochemical methods. SN-LI nerve fibers formed basket-like terminals surrounding many of the postganglionic neurons of the superior cervical, stellate, paravertebral chain ganglia, coeliac/superior mesenteric and inferior mesenteric ganglia. Postganglionic neurons of the superior cervical and other sympathetic ganglia exhibited low-to-moderate levels of SN-LI. In all these sympathetic ganglia, clusters of small diameter (< 10 microm) cells, which may correspond to the small intensely fluorescent (SIF) cells, were found to be intensely labeled. Surgical sectioning or ligation of the cervical sympathetic trunk for 7-10 days resulted in a nearly total loss of SN-LI fibers in the superior cervical ganglia, whereas immunoreactivity in the postganglionic neurons and small diameter cells remained essentially unchanged. In the thoracolumbar and sacral segments of the spinal cord, SN-LI nerve fibers were detected in the superficial layers of the dorsal horn as well as in the intermediolateral cell column (ILp). Occasionally, SN-LI somata were noted in the ILp. SN-LI nerve fibers formed a delicate plexus underneath the capsule of the adrenal gland, some of which traversed the adrenal cortex and reached the adrenal medulla. While heavily invested with SN-LI nerve terminals, chromaffin cells seemed to express a low level of SN-LI. In the enteric plexus, varicose SN-LI nerve fibers and terminals formed a pericellular network around many myenteric and submucous ganglion cells; the ganglionic neurons were lightly to moderately labeled. A population of ganglion cells in the dorsal root, nodose and trigeminal ganglia exhibited moderate-to-strong SN-LI. The detection of SN-LI in nerve fibers and somata of various sympathetic ganglia, enteric plexus and adrenal medulla and in somata of the sensory ganglia implies an extensive involvement of this peptide in sympathetic, enteric and sensory signal processing.
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Affiliation(s)
- N J Dun
- Department of Anatomy and Neurobiology, Medical College of Ohio, Toledo 43614, USA
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Ho CL, Lin YL, Chen WC, Hwang LL, Yu HM, Wang KT. Structural requirements for the edema-inducing and hemolytic activities of mastoparan B isolated from the hornet (Vespa basalis) venom. Toxicon 1996; 34:1027-35. [PMID: 8896194 DOI: 10.1016/0041-0101(96)00046-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mastoparan B (MP-B) is a cationic tetradecapeptide isolated from the black-bellied hornet (Vespa basalis) venom. It has a primary structure (LKLKSIVSWAKKVL-CONH2) distinct from other vespine mastoparans. The peptide caused a dose-dependent swelling in rat hind paw and showed a potent hemolytic activity in guinea pig red blood cells. Studies on the structure activity relationship of the peptide showed that replacing lysine at position 2 (Lys2) by asparagine (Asn) in the MP-B sequence caused about 40% decrease in its edema-inducing activity at 50 micrograms/paw and 90% decrease in hemolytic activity at 30 microM of the peptide, while the same substitution at Lys4 did not cause a significant change in either activity. Replacing either Lys11 or Lys12 by leucine (Leu) caused little or no decrease in the edema-inducing and hemolytic activities. Decreases in both activities were observed when both Lys11 and Lys12 were replaced by Leu. On the other hand, replacing tryptophan at position 9 (Trp9) by tyrosine or phenylalanine in MP-B sequence almost abolished its hemolytic activity, while the edema-inducing activity was only partially inhibited. Circular dichroism spectra of the peptides measured in 20% trifluoro-ethanol revealed that substitution of Lys and Trp did not cause a significant change in the conformation of MP-B. it appears that Lys2 is crucial for both hemolytic and edema-inducing activities of MP-B, while Trp9 is of special importance to the hemolytic activity of MP-B. Lys11 and Lys12 in MP-B probably play a lesser role in both activities.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
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Ho CL, Lin YL, Chen WC, Yu HM, Wang KT, Hwang LL, Chen CT. Immunogenicity of mastoparan B, a cationic tetradecapeptide isolated from the hornet (Vespa basalis) venom, and its structural requirements. Toxicon 1995; 33:1443-51. [PMID: 8744984 DOI: 10.1016/0041-0101(95)00093-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mastoparan B (MP-B) is a cationic tetradecapeptide (LKLKSIVSWAKKVL-CONH2, mol. wt 1611) isolated from the black-bellied hornet (Vespa basalis) venom. The small peptide itself was capable of inducing antibodies without prior conjugation to a protein carrier in rabbits and mice. The mouse antibody was found to be of IgG1 isotype with kappa-type light chain. The peptide antigen was able to form insoluble complexes with the specific antibody, suggesting that MP-B possessed more than one epitope in its molecule. The finding that MP-B was able to bind with both mouse and rabbit antibodies in sandwich ELISA supports this contention. Synthetic MP-B analogues in which lysine at position 2, 4, 11 or 12 was replaced by neutral amino acids such as asparagine or leucine showed a significant decrease in their antibody-binding activities. Substitution of lysine at position 4 (Lys4) caused the most marked inhibition in its binding activity. However, replacing tryptophan at position 9 by tyrosine caused a relatively small reduction in its binding activity. Replacing both Lys2,4 by asparagine or removing Lys-containing segments at amino or carboxyl terminus in MP-B sequence caused a remarkable decrease in the antibody-binding and immunogenic activities of the peptide. The Lys residues located at amino and carboxyl terminal segments of MP-B, especially Lys4, appear to play a critical role in the binding interaction and the immunogenicity of the peptide.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, R.O.C
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Dun NJ, Dun SL, Hwang LL, Förstermann U. Infrequent co-existence of nitric oxide synthase and parvalbumin, calbindin and calretinin immunoreactivity in rat pontine neurons. Neurosci Lett 1995; 191:165-8. [PMID: 7543992 DOI: 10.1016/0304-3940(95)11582-h] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Neurons in the laterodorsal tegmental nucleus (LDTg), ventrolateral dorsal tegmental nucleus (LDTgV), pedunculopontine tegmental nucleus (PPTg), lateral and medial parabrachial nuclei (LPB and MPB) were immunoreactive to brain nitric oxide synthase (NOS) or isoform I. Double-labeling experiments showed that very few NOS-containing neurons in the pons were immunoreactive to any of the three calcium-binding proteins: calbindin-D 28K (CB-IR), parvalbumin (PV-IR) and calretinin (CR-IR). These findings extend our previous observation in the neocortex and suggest that a population of central NOS-containing neurons can be neurochemically characterized as CB/CR/PV deficient.
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Affiliation(s)
- N J Dun
- Department of Anatomy and Neurobiology, Medical College of Ohio, Toledo 43699, USA
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Abstract
Mastoparan B is a cationic, amphiphilic tetradecaeptide (LKLKSIVSWAKKVL-CONH2) isolated from the venom of the hornet Vespa basalis. Intravenous injection of the peptide into rats caused a profound depression of blood pressure and cardiac function, which was inhibited by cyproheptadine, reserpine and multiple doses of compound 48/80, but not by diphenhydramine and cromolyn. Mastoparan from Paravespula lewisii showed little cardiovascular inhibitory activity. A synthetic mastoparan B analog in which lysine at position 2 was replaced by asparagine showed a marked decrease in the cardiovascular depressor effects, while replacing lysine at position 4, 11 or 12 with leucine did not cause a significant reduction in these effects. Replacing lysine at position 12 with leucine even caused a more sustained depressor effect. However, the analog in which lysines at positions 11 and 12 were replaced by leucine lost its cardiovascular inhibitory activity. Replacing tryptophan at position 9 with phenylalanine in mastoparan B did not affect its activity. It is concluded that mastoparan B is involved in the cardiovascular disturbances induced by the hornet venom. Lysine at position 2 is a critical residue for the cardiovascular effects of mastoparan B. A peptide molecule with two lysine residues, one located close to the amino terminus and the other near the carboxyl end of the peptide, appears to be the optimal structure for eliciting the cardiovascular depressor effects.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, ROC
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Ho CL, Hwang LL, Chen CT. Edema-inducing activity of a lethal protein with phospholipase A1 activity isolated from the black-bellied hornet (Vespa basalis) venom. Toxicon 1993; 31:605-13. [PMID: 7687388 DOI: 10.1016/0041-0101(93)90115-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The lethal protein of the hornet (Vespa basalis) venom is a phospholipase A1 toxin (mol. wt approximately 32,000) with a potent hemolytic activity. Subplantar injection of the toxin caused a dose-dependent swelling in the rat hind paw. Its potency was higher than those of phospholipases A2 and cardiotoxin from cobra venoms. Hind-paw edema induced by the toxin was inhibited by antiserotonin drugs (cyproheptadine and methysergide), indomethacin and betamethasone. Antihistamine (chlorpheniramine) showed a relatively weak inhibition. Intradermal injection of the toxin into back skin of the rat also induced local edema which was inhibited by chlorpheniramine and methysergide. Rats pretreated with multiple doses of compound 48/80 showed a moderate decrease in the histamine and serotonin content of rat skin, and a slight decrease in paw edema induced by the toxin, while a single dose of reserpine markedly diminished the toxin-induced edema in association with depletion of serotonin in rat skin. The edema-inhibitory action of amine-depleting agents appeared to correlate with their potencies to deplete serotonin in the skin. It is suggested that serotonin, prostaglandin E2, and to a lesser extent of histamine are involved in producing the local effect of the toxin. However, serotonin released by the toxin appears to be the major factor mediating the toxin-induced edema in the rat.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, R.O.C
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45
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Abstract
By gel filtration on a Fractogel TSK HW 50 column followed by cation-exchange chromatography on CM-Trisacryl M, a tetradecapeptide amide, designated 'mastoparan B', was purified from the venom of the hornet Vespa basalis. Its amino acid sequence was determined as: Leu-Lys-Leu-Lys-Ser-Ile-Val-Ser-Trp-Ala-Lys-Lys-Val-Leu-NH2 and its molecular mass was measured to be 1611 Da by fast-atom-bombardment mass spectrometry. In addition to having a common structure of vespid mastoparans, the peptide shows a less hydrophobic sequence at positions 1, 2, 5, 8 and 9. The peptide caused liberation of histamine from rat peritoneal mast cells and induced oedema in the rat paw. However, the latter effect was inhibited by 'anti-serotonin' (anti-5-hydroxytryptamine) (cyproheptadine), but not by antihistamine (chlorpheniramine). The peptide also possesses a potent haemolytic activity which acts in synergy with the lethal protein of the venom, suggesting the possible involvement of mastoparan B in the lethal effect of Vespa basalis venom.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
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46
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Abstract
The black-bellied hornet, Vespa basalis, is one of the most dangerous species of wasp in Taiwan. The hornet venom possesses a potent edema-inducing activity in addition to its lethal cardiovascular effect. Rat hind-paw edema induced by the venom was inhibited significantly by antiserotonin compounds (cyproheptadine and methysergide) but not by antihistaminics (chlorpheniramine and diphenhydramine), betamethasone, cromolyn, indomethacin plus nordihydroguaiaretic acid, cellulose sulfate, aprotinin or captopril. However, chlorpheniramine or betamethasone, when given in combination with cyproheptadine, showed a significant further inhibition of the venom-induced edema. Pretreating the rat with compound 48/80 reduced the edematous response to the venom. Four venom components, i.e. the lethal protein, mastoparan B, fraction 3 (containing protease) and fraction 15 (containing serotonin) were involved in the edematous effect of the venom. Paw edema induced by the crude venom and its protein components (lethal protein, mastoparan B and fraction 3) was similar in their responses to antiserotonin compounds and antihistamine (inhibited by cyproheptadine and methysergide but not by chlorpheniramine), while that induced by fraction 15 was inhibited by both. It is postulated that upon hornet stings, fraction 15 is acting as an exogenous serotonin, while the protein components, especially the lethal protein, are responsible for the release of endogenous autacoids in which serotonin plays the most important role in inducing local edema.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, Republic of China
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Chang CC, Chiou LC, Hwang LL, Huang CY. Mechanisms of the synergistic interactions between organic calcium channel antagonists and various neuromuscular blocking agents. Jpn J Pharmacol 1990; 53:285-92. [PMID: 2167989 DOI: 10.1254/jjp.53.285] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of Mn2+, neomycin and four organic Ca2(+)-channel antagonists (OCA): nicardipine, nifedipine, diltiazem and verapamil on the neuromuscular blocking activities of tubocurarine, succinylcholine (SCh), decamethonium and neomycin were studied in isolated mouse phrenic nerve-diaphragm preparations. The effective concentration of SCh for 50% inhibition (IC50) of single indirect twitch responses were reduced markedly by more than 3-fold when the preparations were pretreated with OCA at 10 microM; the latter alone did not appreciably affect the indirect twitch response or the amplitude of miniature endplate potentials. The neuromuscular blocking effect of decamethonium was also enhanced synergistically by OCA to a similar extent. On the other hand, under the comparable condition. the combined uses of OCA plus tubocurarine or neomycin, neomycin plus tubocurarine or SCh, and Mn2+ plus tubocurarine, SCh or neomycin all resulted in insignificant potentiation. These results suggest that OCA have a specific effect to enhance the agonist effect of depolarizing agents on nicotinic acetylcholine receptors. Nicardipine at 2 microM non-competitively inhibited depolarizations of endplates elicited by SCh and decamethonium and abolished them completely at 10 microM nicardipine. The IC50's in inhibiting endplate potentials and miniature endplate potentials by SCh and decamethonium were also reduced 2 to 3.5-fold by nicardipine. It is inferred that OCA are endowed with a unique capability to allosterically affect the postsynaptic nicotinic acetylcholine receptor, promoting its desensitization liability, hence synergistic interaction with depolarizing agents. Presynaptic effects of OCA are probably not involved.
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Affiliation(s)
- C C Chang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei
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Ho CL, Ko JL, Hwang LL, Wang KT. Analgesic, receptor binding, and peripheral opioid activities of synthetic dermorphin-dynorphin hybrid peptides. Int J Pept Protein Res 1990; 35:99-104. [PMID: 1969854 DOI: 10.1111/j.1399-3011.1990.tb00242.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of substituting the enkephalin moiety of dynorphin with the dermorphin sequence were studied on the receptor preference, analgesic, and peripheral opioid potencies by using synthetic dermorphin-dynorphin hybrid peptides as the probe. Replacement of the enkephalin moiety of dynorphin with the dermorphin or dermorphin1-5 sequences caused a remarkable increase in analgesic potency, and a 3-6 fold increase in potency of binding against [3H]-dihydromorphine. The potency of receptor binding against [3H]-EKC was also increased by incorporation of the whole dermorphin sequence into the dynorphin molecule. In the presence of NaCl (100 mM), the effect of enhancing binding against [3H]-EKC due to dermorphin substitution disappeared, suggesting the contribution of opioid mu-receptor. Peripheral opioid activities assayed by various smooth muscle preparations showed that dermorphin incorporation caused a decreased in the potency of inhibition of the contractions of the guinea pig ileum and the rabbit vas deferens, no change in potency on the mouse vas deferens, and a marked increase in the inhibition of the rat vas deferens. Among the peripheral opioid activities only that assayed with the rat vas deferens appears to correlate approximately with the analgesic and the receptor binding activities. Judging from the relative potencies obtained from all assays, it is evident that the N-terminal dermorphin moiety, but not the C-terminal dynorphin fragment, dominates the opioid activity and receptor preference of the hybrid peptide.
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Affiliation(s)
- C L Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan, R.O.C
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Chang CC, Chiou LC, Hwang LL, Hong SJ, Huang CY. Nicardipine inhibits axon conduction but causes dual changes of acetylcholine release in the mouse motor nerve. Can J Physiol Pharmacol 1989; 67:1493-8. [PMID: 2483357 DOI: 10.1139/y89-241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of nicardipine, a dihydropyridine Ca2(+)-channel antagonist, on neuromuscular transmission and impulse-evoked release of acetylcholine were compared with those of nifedipine. In the isolated mouse phrenic nerve diaphragm, nicardipine (50 microM), but not nifedipine (100 microM), induced neuromuscular block, fade of tetanic contraction, and dropout or all-or-none block of end-plate potentials. Nicardipine had no significant effect on the resting membrane potential and the amplitude of miniature end-plate potentials but increased the frequency and caused the appearance of large size miniature potentials. The quantal contents of evoked end-plate potentials were increased. In the presence of tubocurarine, however, nicardipine depressed the amplitude of end-plate potentials. The compound nerve action potential was also decreased. It is concluded that nicardipine blocks neuromuscular transmission by acting on Na+ channels and inhibits axonal conduction. Nicardipine appeared to affect the evoked release of acetylcholine by dual mechanisms, i.e., an enhancement presumably by an agonist action on Ca2+ channels, like Bay K 8644 and nifedipine, and inhibition by an effect on Na+ channels, like verapamil and diltiazem. In contrast with its inactivity on the amplitude of miniature end-plate potentials, depolarization of the end plate in response to succinylcholine was greatly depressed. The contractile response of baby chick biventer cervicis muscle to exogenous acetylcholine was noncompetitively antagonized by nicardipine (10 microM), but was unaffected by nifedipine (30 microM). These results may implicate that nicardipine blocks the postsynaptic acetylcholine receptor channel by enhancing receptor desensitization or by a use-dependent effect.
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Affiliation(s)
- C C Chang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei
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50
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Chang CC, Chiou LC, Hwang LL. Selective antagonism to succinylcholine-induced depolarization by alpha-bungarotoxin with respect to the mode of action of depolarizing agents. Br J Pharmacol 1989; 98:1413-9. [PMID: 2611499 PMCID: PMC1854799 DOI: 10.1111/j.1476-5381.1989.tb12691.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. The interactions of alpha-bungarotoxin or tubocurarine with the neuromuscular block and endplate depolarization induced by succinylcholine (SCh) in the phrenic nerve-diaphragm preparation of mice were studied in order to elucidate the role of depolarization by SCh in the neuromuscular blockade. 2. The SCh concentrations required to depress the indirect twitch response by 20% and the evoked endplate potential in cut muscle preparations by 80% were 10 microm and 6 microM, respectively, while only 2 microM SCh was needed to induce maximal endplate depolarization from -80 mV to about -60 mV. 3. SCh blocked the neuromuscular transmission synergistically with either alpha-bungarotoxin or tubocurarine. There was an initial partial reversal of the neuromuscular inhibition caused by tubocurarine, but not that by alpha-bungarotoxin. 4. alpha-Bungarotoxin (0.025 microM) antagonized SCh (10 microM)-induced depolarization more effectively than it depressed miniature endplate potentials and the antagonism was insurmountable by increasing SCh concentration. By contrast, tubocurarine preferentially depressed miniature endplate potentials and antagonized SCh-depolarization competitively. 5. The above difference was attributed to the irreversible nature of alpha-bungarotoxin binding to acetylcholine receptors, to the slow diffusion of the toxin molecule into the synaptic cleft and thus to the more rapid binding with perijunctional receptors compared with junctional ones. 6. It is concluded that the sustained depolarization of the endplate by SCh results largely from an action on the perijunctional receptor in mice and, unlike cats, the neuromuscular block by SCh is not due to the depolarization per se but rather to a direct attenuation of endplate potential.
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Affiliation(s)
- C C Chang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei
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