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Zhang SS, Xu TC, Yu Z, Mao JF, Xu B. [Effect of electroacupuncture at "Tianshu" (ST25) on the regulation of nitrergic neurons in different intestinal segments in streptozotocin induced type 2 diabetic rats]. Zhen Ci Yan Jiu 2022; 47:785-792. [PMID: 36153453 DOI: 10.13702/j.1000-0607.20210628] [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] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
OBJECTIVE To observe the effect of electroacupuncture (EA) at "Tianshu" (ST25) on nitrergic neurons in jejunum and distal colon in type 2 diabetic rats, so as to explore its mechanism of regulating different intestinal segments. METHODS Twenty-four SD rats were randomly divided into control, model and EA groups (n=8 in each group). The diabetes model was established by intraperitoneal injection of streptozotocin (35 mg/kg) and high-sugar and high-fat diet for 2 weeks. EA (2 Hz/15 Hz, 2 mA) was applied to bilateral ST25 for 20 min, once a day, 6 days a week for 4 weeks. The intestinal motility was evaluated by observing the first red stool excretion time and the distal colon bead excretion time. HE staining was used to observe the histological changes of jejunum and distal colon. The positive expression and protein expression of intestinal total neuronal marker protein gene product 9.5(PGP9.5) and neuronal nitric oxide synthase (nNOS) in jejunum and distal colon were detected by immunofluorescence staining and Western blot, respectively. RESULTS After modeling, the blood glucose was significantly increased (P<0.01), the first red stool excretion time and the distal colon bead excretion time were shortened (P<0.01), the expression levels of PGP9.5 and nNOS in jejunum and distal colon were decreased (P<0.01) in the model group relevant to the control group. After treatment, compared with the model group, the blood glucose was decreased (P<0.01), the first red stool excretion time and the distal colon bead excretion time were prolonged (P<0.01, P<0.05), and the expression levels of PGP9.5 and nNOS in jejunum and distal colon were increased (P<0.05, P<0.01) in the EA group. HE staining showed disordered structure in intestinal mucosa of the jejunum and distal colon, and reduction of the number of goblet cells in the model group, which was relatively milder in the EA group. CONCLUSION EA can effectively improve the intestinal mucosal damage and restore intestinal motor function in type 2 diabetic rats, which may be related to its function in regulating the number of nitrergic neurons in the intestinal nervous system.
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Affiliation(s)
- Shuang-Shuang Zhang
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Tian-Cheng Xu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Zhi Yu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Jin-Feng Mao
- The Second Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Second Chinese Medicine Hospital, Nanjing 210017
| | - Bin Xu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing 210023, China
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Li YR, Li Y, Jin Y, Xu M, Fan HW, Zhang Q, Tan GH, Chen J, Li YQ. Involvement of nitrergic neurons in colonic motility in a rat model of ulcerative colitis. World J Gastroenterol 2022; 28:3854-3868. [PMID: 36157548 PMCID: PMC9367233 DOI: 10.3748/wjg.v28.i29.3854] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/27/2022] [Accepted: 07/06/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The mechanisms underlying gastrointestinal (GI) dysmotility with ulcerative colitis (UC) have not been fully elucidated. The enteric nervous system (ENS) plays an essential role in the GI motility. As a vital neurotransmitter in the ENS, the gas neurotransmitter nitric oxide (NO) may impact the colonic motility. In this study, dextran sulfate sodium (DSS)-induced UC rat model was used for investigating the effects of NO by examining the effects of rate-limiting enzyme nitric oxide synthase (NOS) changes on the colonic motility as well as the role of the ENS in the colonic motility during UC. AIM To reveal the relationship between the effects of NOS expression changes in NOS-containing nitrergic neurons and the colonic motility in a rat UC model. METHODS Male rats (n = 8/each group) were randomly divided into a control (CG), a UC group (EG1), a UC + thrombin derived polypeptide 508 trifluoroacetic acid (TP508TFA; an NOS agonist) group (EG2), and a UC + NG-monomethyl-L-arginine monoacetate (L-NMMA; an NOS inhibitor) group (EG3). UC was induced by administering 5.5% DSS in drinking water without any other treatment (EG1), while the EG2 and EG3 were gavaged with TP508 TFA and L-NMMA, respectively. The disease activity index (DAI) and histological assessment were recorded for each group, whereas the changes in the proportion of colonic nitrergic neurons were counted using immunofluorescence histochemical staining, Western blot, and enzyme linked immunosorbent assay, respectively. In addition, the contractile tension changes in the circular and longitudinal muscles of the rat colon were investigated in vitro using an organ bath system. RESULTS The proportion of NOS-positive neurons within the colonic myenteric plexus (MP), the relative expression of NOS, and the NOS concentration in serum and colonic tissues were significantly elevated in EG1, EG2, and EG3 compared with CG rats. In UC rats, stimulation with agonists and inhibitors led to variable degrees of increase or decrease for each indicator in the EG2 and EG3. When the rats in EGs developed UC, the mean contraction tension of the colonic smooth muscle detected in vitro was higher in the EG1, EG2, and EG3 than in the CG group. Compared with the EG1, the contraction amplitude and mean contraction tension of the circular and longitudinal muscles of the colon in the EG2 and EG3 were enhanced and attenuated, respectively. Thus, during UC, regulation of the expression of NOS within the MP improved the intestinal motility, thereby favoring the recovery of intestinal functions. CONCLUSION In UC rats, an increased number of nitrergic neurons in the colonic MP leads to the attenuation of colonic motor function. To intervene NOS activity might modulate the function of nitrergic neurons in the colonic MP and prevent colonic motor dysfunction. These results might provide clues for a novel approach to alleviate diarrhea symptoms of UC patients.
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Affiliation(s)
- Yan-Rong Li
- Department of Human Anatomy, Basic Medical College, Guangxi Medical University, Nanning 530000, Guangxi Zhuang Autonomous Region, China
- Department of Gastroenterology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou 121000, Liaoning Province, China
| | - Yan Li
- Department of Human Anatomy, Basic Medical College, Zunyi Medical University, Zunyi 563006, Guizhou Province, China
| | - Yuan Jin
- Department of Human Anatomy, Basic Medical College, Zunyi Medical University, Zunyi 563006, Guizhou Province, China
| | - Mang Xu
- Department of Anatomy, Basic Medical College, Dali University, Dali 671000, Yunnan Province, China
| | - Hong-Wei Fan
- Department of Anatomy, Histology and Embryology, Xuzhou Medical University, Xuzhou 221000, Jiangsu Province, China
| | - Qian Zhang
- Department of Human Anatomy, Basic Medical College, Zunyi Medical University, Zunyi 563006, Guizhou Province, China
| | - Guo-He Tan
- Key Lab of Longevity and Aging-related Diseases of Chinese Ministry of Education, Guangxi Medical University, Nanning 530000, Guangxi Zhuang Autonomous Region, China
- School of Basic Medical Sciences and Center for Translational Medicine, Guangxi Medical University, Nanning 530000, Guangxi Zhuang Autonomous Region, China
| | - Jing Chen
- Department of Anatomy, Histology and Embryology and K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Yun-Qing Li
- Department of Human Anatomy, Basic Medical College, Guangxi Medical University, Nanning 530000, Guangxi Zhuang Autonomous Region, China
- Department of Human Anatomy, Basic Medical College, Zunyi Medical University, Zunyi 563006, Guizhou Province, China
- Department of Anatomy, Histology and Embryology and K. K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
- Department of Human Anatomy, College of Preclinical Medical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
- Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 571199, Hainan Province, China
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Di Natale MR, Hunne B, Liew JJM, Fothergill LJ, Stebbing MJ, Furness JB. Morphologies, dimensions and targets of gastric nitric oxide synthase neurons. Cell Tissue Res 2022. [PMID: 35146560 DOI: 10.1007/s00441-022-03594-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/21/2022] [Indexed: 11/02/2022]
Abstract
We investigated the distributions and targets of nitrergic neurons in the rat stomach, using neuronal nitric oxide synthase (NOS) immunohistochemistry and nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry. Nitrergic neurons comprised similar proportions of myenteric neurons, about 30%, in all gastric regions. Small numbers of nitrergic neurons occurred in submucosal ganglia. In total, there were ~ 125,000 neuronal nitric oxide synthase (nNOS) neurons in the stomach. The myenteric cell bodies had single axons, type I morphology and a wide range of sizes. Five targets were identified, the longitudinal, circular and oblique layers of the external muscle, the muscularis mucosae and arteries within the gastric wall. The circular and oblique muscle layers had nitrergic fibres throughout their thickness, while the longitudinal muscle was innervated at its inner surface by fibres of the tertiary plexus, a component of the myenteric plexus. There was a very dense innervation of the pyloric sphincter, adjacent to the duodenum. The muscle strands that run between mucosal glands rarely had closely associated nNOS nerve fibres. Both nNOS immunohistochemistry and NADPH histochemistry showed that nitrergic terminals did not provide baskets of terminals around myenteric neurons. Thus, the nitrergic neuron populations in the stomach supply the muscle layers and intramural arteries, but, unlike in the intestine, gastric interneurons do not express nNOS. The large numbers of nNOS neurons and the density of innervation of the circular muscle and pyloric sphincter suggest that there is a finely graded control of motor function in the stomach by the recruitment of different numbers of inhibitory motor neurons.
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Brasileiro AD, Garcia LP, de Carvalho da Silva S, Rocha LB, Pedrosa AL, Vieira AS, da Silva VJD, Rodrigues ARA. Effects of diabetes mellitus on myenteric neuronal density and sodium channel expression in the rat ileum. Brain Res 2019; 1708:1-9. [PMID: 30500400 DOI: 10.1016/j.brainres.2018.11.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 11/09/2018] [Accepted: 11/26/2018] [Indexed: 12/25/2022]
Abstract
Diabetes mellitus (DM) may lead to gastrointestinal motility disorders. Rodent models of DM indicate the presence of morpho-functional abnormalities of the enteric nervous system. Here, we evaluated whether experimental DM can cause changes in the excitatory cholinergic fibers, neuronal density, and voltage-gated sodium channel (Nav) expression in the myenteric plexus of the ileum. After streptozotocin-induced hyperglycemia in female rats progressed for eight weeks, triple immunofluorescence labeling experiments revealed that the neuronal density in DM rats was significantly lower than that in control. On average, the density of total neurons reduced by 52.2% (p = 0.0001), cholinergic neurons by 50.0% (p = 0.0068), and nitrergic neurons by 54.8% (p = 0.0042). The number of neurons per ganglionic area was also significantly reduced (to 28.2% of total neurons, p = 0.0002; 27.7% of cholinergic neurons, p = 0.0002, and 32.1% of nitrergic neurons, p = 0.0016). Furthermore, the density of the cholinergic fibers at the surface of the longitudinal muscle was significantly reduced (DM: 24 ± 3%; p = 0.003, control: 41 ± 2%); however, western-blot analysis did not indicate a reduction in the expression of choline acetyltransferase (ChAT) in the DM group. The Nav1.6 isoform was detected in different myenteric neurons of the ileum. RT-qPCR data did not suggest an alteration of transcripts for ChAT, neuronal nitric oxide synthase, Nav1.3, Nav1.6, or Nav1.7. Our data support the view that chronic DM leads to a reduction of excitatory cholinergic fibers and neuronal density. However, changes in sodium channel expression pattern, which could cause neuronal dysfunction, were not detected.
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Bódi N, Szalai Z, Chandrakumar L, Bagyánszki M. Region-dependent effects of diabetes and insulin-replacement on neuronal nitric oxide synthase- and heme oxygenase-immunoreactive submucous neurons. World J Gastroenterol 2017; 23:7359-7368. [PMID: 29151690 PMCID: PMC5685842 DOI: 10.3748/wjg.v23.i41.7359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/26/2017] [Accepted: 08/25/2017] [Indexed: 02/07/2023] Open
Abstract
AIM To investigate the intestinal segment-specific effects of diabetes and insulin replacement on the density of different subpopulations of submucous neurons.
METHODS Ten weeks after the onset of type 1 diabetes samples were taken from the duodenum, ileum and colon of streptozotocin-induce diabetic, insulin-treated diabetic and sex- and age-matched control rats. Whole-mount preparations of submucous plexus were prepared from the different gut segments for quantitative fluorescent immunohistochemistry. The following double-immunostainings were performed: neuronal nitric oxide synthase (nNOS) and HuC/D, heme oxygenase (HO) 1 and peripherin, as well as HO2 and peripherin. The density of nNOS-, HO1- and HO2-immunoreactive (IR) neurons was determined as a percentage of the total number of submucous neurons.
RESULTS The total number of submucous neurons and the proportion of nNOS-, HO1- and HO2-IR subpopulations were not affected in the duodenal ganglia of control, diabetic and insulin-treated rats. While the total neuronal number did not change in either the ileum or the colon, the density of nitrergic neurons exhibited a 2- and 3-fold increase in the diabetic ileum and colon, respectively, which was further enhanced after insulin replacement. The presence of HO1- and HO2-IR submucous neurons was robust in the colon of controls (38.4%-50.8%), whereas it was significantly lower in the small intestinal segments (0.0%-4.2%, P < 0.0001). Under pathophysiological conditions the only alteration detected was an increase in the ileum and a decrease in the colon of the proportion of HO-IR neurons in insulin-treated diabetic animals.
CONCLUSION Diabetes and immediate insulin replacement induce the most pronounced region-specific alterations of nNOS-, HO1- and HO2-IR submucous neuronal density in the distal parts of the gut.
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Affiliation(s)
- Nikolett Bódi
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Zita Szalai
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Lalitha Chandrakumar
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
| | - Mária Bagyánszki
- Department of Physiology, Anatomy and Neuroscience, Faculty of Science and Informatics, University of Szeged, H-6726 Szeged, Hungary
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Florian V, Caroline F, Francis C, Camille S, Fabielle A. Leptin modulates enteric neurotransmission in the rat proximal colon: an in vitro study. ACTA ACUST UNITED AC 2013; 185:73-8. [PMID: 23816465 DOI: 10.1016/j.regpep.2013.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [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: 06/05/2012] [Revised: 03/21/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022]
Abstract
Leptin has been shown to modulate gastrointestinal functions including nutrient absorption, growth, and inflammation and to display complex effects on gut motility. Leptin receptors have also been identified within the enteric nervous system (ENS), which plays a crucial role in digestive functions. Although leptin has recently been shown to activate neurons in the ENS, the precise mechanisms involved are so far unknown. Therefore, the aim of the present study was to determine the effects of leptin on rat proximal colon smooth muscle and enteric neuron activities. The effects of exogenous leptin on tone and on responses to transmural nerve stimulation (TNS) of isolated circular smooth muscle of proximal colon in rats were investigated using an organ bath technique. The effects of a physiological concentration (0.1 μM) of leptin were also studied on tone and TNS-induced relaxation in the presence of atropine, hexamethonium, L-N(G)-nitroarginine methyl ester (L-NAME) and capsazepine. Leptin caused a slight but significant decrease in tone, TNS-induced relaxation and contraction in a concentration-dependent manner in colonic preparations. Cholinergic antagonists abolished the effects of 0.1 μM leptin on TNS-induced relaxation. This concentration of leptin had no further effect on relaxation in the presence of L-NAME. In the presence of capsazepine, leptin had no further effect either on tone or relaxation compared to the drug alone. In conclusion, leptin modulates the activity of enteric inhibitory and excitatory neurons in proximal colon. These effects may be mediated through nitrergic neurons. Intrinsic primary afferent neurons may be involved.
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Affiliation(s)
- Voinot Florian
- Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, 23 rue Becquerel, 67087 Strasbourg, France; CNRS, UMR7178, 67037 Strasbourg, France
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Bagyánszki M, Bódi N. Diabetes-related alterations in the enteric nervous system and its microenvironment. World J Diabetes 2012; 3:80-93. [PMID: 22645637 PMCID: PMC3360223 DOI: 10.4239/wjd.v3.i5.80] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 04/06/2012] [Accepted: 05/11/2012] [Indexed: 02/05/2023] Open
Abstract
Gastric intestinal symptoms common among diabetic patients are often caused by intestinal motility abnormalities related to enteric neuropathy. It has recently been demonstrated that the nitrergic subpopulation of myenteric neurons are especially susceptible to the development of diabetic neuropathy. Additionally, different susceptibility of nitrergic neurons located in different intestinal segments to diabetic damage and their different levels of responsiveness to insulin treatment have been revealed. These findings indicate the importance of the neuronal microenvironment in the pathogenesis of diabetic nitrergic neuropathy. The main focus of this review therefore was to summarize recent advances related to the diabetes-related selective nitrergic neuropathy and associated motility disturbances. Special attention was given to the findings on capillary endothelium and enteric glial cells. Growing evidence indicates that capillary endothelium adjacent to the myenteric ganglia and enteric glial cells surrounding them are determinative in establishing the ganglionic microenvironment. Additionally, recent advances in the development of new strategies to improve glycemic control in type 1 and type 2 diabetes mellitus are also considered in this review. Finally, looking to the future, the recent and promising results of metagenomics for the characterization of the gut microbiome in health and disease such as diabetes are highlighted.
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Affiliation(s)
- Mária Bagyánszki
- Mária Bagyánszki, Nikolett Bódi, Department of Physiology, Anatomy and Neuroscience, Faculty of Science, University of Szeged, H-6726 Szeged, Hungary
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