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Sato Y, Yamaguchi K, Ogawa M, Takekuma Y, Sugawara M. An imaging approach for determining the mechanism of enhancement of intestinal absorption of an L-theanine supplement. PLoS One 2021; 16:e0253066. [PMID: 34115818 PMCID: PMC8195392 DOI: 10.1371/journal.pone.0253066] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 05/28/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND & OBJECTIVE Theanine (L-glutamylethylamide) contained in green tea is a functional food component that has been attracting attention due to its relaxation effect. It was shown that the ingredients added to the theanine formulations increased the absorption of theanine. If this mechanism can be elucidated, it would be possible to contribute to development of evidence-based formulations. In this study, we investigated the effect of ingredients in the formulations on the absorption of theanine in detail. MAIN METHODS After oral administration of a mixture of theanine and additional components to Wistar rats the plasma concentration was determined by an HPLC and the pharmacokinetic parameters were calculated. In addition, a new system for evaluating intestinal blood flow was developed since the involvement of intestinal blood flow was considered as a factor that increased absorption of theanine. KEY FINDINGS Plasma concentration of theanine increased significantly in the combined use group with eight ingredients containing piperine as compared with theanine only group. Piperine would increase theanine absorption by increased blood flow, not an inhibition of metabolism. We succeeded to develop a visual and quantitative system to evaluate the effect of these ingredients directly including piperine on the intestinal blood flow using indocyanine green while maintaining physiological conditions. SIGNIFICANCE Increased intestinal blood flow by these ingredients including piperine enhanced the absorption of theanine. Other mechanisms may also be considered as the mechanism by which theanine absorption is increased in addition to increased blood flow.
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Affiliation(s)
- Yuki Sato
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Kazuki Yamaguchi
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mikako Ogawa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
- Global Station for Biosurfaces and Drug Discovery, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yoh Takekuma
- Department of Pharmacy, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Mitsuru Sugawara
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
- Global Station for Biosurfaces and Drug Discovery, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido, Japan
- Department of Pharmacy, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
- * E-mail:
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Kurzepa J, Szpetnar M, Hordyjewska A, Wątroba S, Gołąb P, Boguszewska-Czubara A. Thrombolytic treatment decreases glutamate/GABA ratio in serum during acute ischaemic stroke: a pilot study. Neurol Res 2015; 37:934-7. [PMID: 26005019 DOI: 10.1179/1743132815y.0000000049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
There is no information about possible effect of recombinant tissue plasminogen activator (rtPA) therapy on excitotoxic/neuroprotective amino acids during acute phase of ischaemic stroke (IS). Our purpose was to evaluate iv thrombolytic treatment on glutamate (Glu) and gamma-aminobutyric acid (GABA) serum levels during acute IS. Eleven thrombolytic (rtPA group) and 12 non-thrombolytic (non-rtPA group) patients with acute IS were enrolled. The serum samples were obtained at three time points for rtPA group (time point 0: first to fourth hour of stroke; time point 1: immediately after rtPA administration; time point 2: on days 5-7 from stroke onset). The remaining patients had blood collection at two time points: time point 1: 5(th)-10(th) hour of stroke and time point 2: on days 5-7 of stroke. Glutamate and GABA were determined by the automated ion-exchange chromatography using Amino Acids Analyser (AAA 400) by INGOS Corp., Praha, Czech Republic. The statistically significant elevation of GABA serum level was noticed directly after thrombolysis (time point 1) in comparison to the corresponding time point in non-rtPA group [0.016 (0.002-0.032) μM/ml vs 0.001 (0.001-0.004) μM/ml for rtPA vs non-rtPA groups, respectively, median (first to third quartile), P < 0.05]. At the same time point, the Glu/GABA ratio was significantly decreased in rtPA group (P < 0.05) suggesting the decrease of excitotoxicity biomarkers in the blood after thrombolysis. Considering the beneficial effect of GABA receptor agonists, the elevation of GABA by rtPA should bring an additional positive features of thrombolytic treatment.
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Coraim FI, Owen A, Trubel W, Kassal H, Widhalm K. Regulatory effect of neurotransmitter by hemofiltration in cardiogenic shock patients after open heart surgery. Contrib Nephrol 2015; 93:90-3. [PMID: 1686998 DOI: 10.1159/000420193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- F I Coraim
- Department of Anesthesiology and Intensive Care, University of Vienna, Austria
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Teijema HL, Brubakk AM, van Gelderen HH, Ruys JH. Glutamic acidemia. Monogr Hum Genet 2015; 9:75-9. [PMID: 732854 DOI: 10.1159/000401613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Yang JY, Moon E, Nam SH, Friedman M. Antidiabetic effects of rice hull smoke extract on glucose-regulating mechanism in type 2 diabetic mice. J Agric Food Chem 2012; 60:7442-7449. [PMID: 22803686 DOI: 10.1021/jf3017749] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The aim of this study is to determine the protective effect of a liquid rice hull smoke extract (RHSE) against type 2 diabetes (T2D) in mice induced by a high-fat diet. As compared to the control group of mice on a high-fat diet (HFD), feeding the HFD supplemented with 0.5% or 1% RHSE for 7 weeks resulted in significantly reduced blood glucose and triglyceride and cholesterol concentrations, higher serum insulin levels, and improved glucose tolerance, as assessed by an oral glucose tolerance assay. The hypoglycemic effect of RHSE was accompanied by changes in enzyme activities and cognate gene expression assessed using RT-PCR. Among the glucose metabolism regulating genes evaluated, hepatic glucokinase (GCK), the glucose transporters GLUT2 and GLUT4, and peroxisome proliferator-activated receptor-γ (PPAR-γ) were up-regulated, whereas glucose-6-phosphatase (G6 Pase) and phosphoenolpyruvate carboxykinase (PEPCK) were down-regulated in the liver of mice with RHSE-supplementation. These changes resulted in restoration of glucose-regulating activities to normal control levels. Histopathology showed that a high-fat diet intake also induced liver necrosis and damage of the islet of Langerhans in the pancreas, whereas RHSE supplementation restored necrotic damage to normal levels. Immunohistochemistry showed that RHSE supplementation can restore the reduced insulin-producing β-cell population in islet of Langerhans associated with a high-fat diet intake to nondiabetic normal control levels in a dose-dependent manner. RHSE-supplemented food could protect insulin-producing islet cells against damage triggered by oxidative stress and local inflammation associated with diabetes.
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Affiliation(s)
- Jun Young Yang
- Department of Biological Science, Ajou University , Suwon, 443-749, Republic of Korea
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Boyko M, Stepensky D, Gruenbaum BF, Gruenbaum SE, Melamed I, Ohayon S, Glazer M, Shapira Y, Zlotnik A. Pharmacokinetics of glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase and their blood glutamate-lowering activity in naïve rats. Neurochem Res 2012; 37:2198-205. [PMID: 22846966 DOI: 10.1007/s11064-012-0843-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 06/27/2012] [Accepted: 07/13/2012] [Indexed: 11/26/2022]
Abstract
Traumatic brain injury (TBI) and stroke lead to elevated levels of glutamate in the brain that negatively affect the neurological outcomes in both animals and humans. Intravenous administration of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) enzymes can be used to lower the blood glutamate levels and to improve the neurological outcome following TBI and stroke. The objective of this study was to analyze the pharmacokinetics and to determine the glutamate-lowering effects of GOT and GPT enzymes in naïve rats. We determined the time course of serum GOT, GPT, and glutamate levels following a single intravenous administration of two different doses of each one of the studied enzymes. Forty-six male rats were randomly assigned into one of 5 treatment groups: saline (control), human GOT at dose 0.03 and 0.06 mg/kg and porcine GPT at dose 0.6 and 1.2 mg/kg. Blood samples were collected at baseline, 5 min, and 2, 4, 8, 12, and 24 h after the drug injection and GOT, GPT and glutamate levels were determined. The pharmacokinetics of both GOT and GPT followed one-compartment model, and both enzymes exhibited substantial glutamate-lowering effects following intravenous administration. Analysis of the pharmacokinetic data indicated that both enzymes were distributed predominantly in the blood (central circulation) and did not permeate to the peripheral organs and tissues. Several-hour delay was present between the time course of the enzyme levels and the glutamate-lowering effects (leading to clock-wise hysteresis on concentration-effect curves), apparently due to the time that is required to affect the pool of serum glutamate. We conclude that the interaction between the systemically-administered enzymes (GOT and GPT) and the glutamate takes place in the central circulation. Thus, glutamate-lowering effects of GOT and GPT apparently lead to redistribution of the excess glutamate from the brain's extracellular fluid into the blood and can reduce secondary brain injury due to glutamate neurotoxicity. The outcomes of this study regarding the pharmacokinetic and pharmacodynamic properties of the GOT and GPT enzymes will be subsequently verified in clinical studies that can lead to design of effective neuroprotective treatment strategies in patients with traumatic brain diseases and stroke.
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Affiliation(s)
- Matthew Boyko
- Department of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer Sheva, Israel
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Abstract
Circulating levels of 5-hydroxytryptamine (5HT), histamine, monoamine oxidase (MAO), histaminase, tri-iodothyronine (T3) and thyroxine (T4) were studied in L-thyroxine and carbimazole treated rats. Increased concentrations of 5-HT, histamine, glutamate, T3 and T4 were recorded in L-thyroxine-treated rats while plasma gamma-aminobutyric acid (GABA), MAO and histaminase levels were significantly decreased. Considerable reduction in 5-HT, glutamate, T3 and T4 with trend towards the rise in plasma levels of MAO and histaminase was noticed in carbimazole treated group. There was a significant correlation between these amines and thyroid hormone values. The findings suggest that alterations in the metabolism of thyroid hormones may have a link with the altered metabolism of biogenic amines.
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Affiliation(s)
- L Upadhyaya
- Department of Medicine, Banaras Hindu University, Varanasi, India
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Pødenphant J, Christiansen C, Catherwood BD, Deftos LJ. Serum bone Gla protein and other biochemical estimates of bone turnover in early postmenopausal women during prophylactic treatment for osteoporosis. Acta Med Scand 2009; 218:329-33. [PMID: 3907290 DOI: 10.1111/j.0954-6820.1985.tb06133.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Serum bone Gla protein (BGP) and conventional biochemical indices of bone metabolism were determined in 66 early postmenopausal women during a double-blind therapeutic trial performed to investigate the effect of oestrogen, calcium and 1,25 (OH)2D3 on postmenopausal osteoporosis. The biochemical variables were determined before, during and after withdrawal of therapy. We found a very high correlation between serum BGP and serum alkaline phosphatase--a measure of bone formation, less high correlation between serum BGP and the remaining parameters--indices of bone resorption. It is concluded that serum BGP probably reflects bone formation and may prove to be a useful new biochemical marker.
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Choi YK, Jo PG, Choi CY. Cadmium affects the expression of heat shock protein 90 and metallothionein mRNA in the Pacific oyster, Crassostrea gigas. Comp Biochem Physiol C Toxicol Pharmacol 2008; 147:286-92. [PMID: 18234560 DOI: 10.1016/j.cbpc.2007.11.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [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] [Received: 10/01/2007] [Revised: 11/19/2007] [Accepted: 11/19/2007] [Indexed: 11/17/2022]
Abstract
Cadmium (Cd) is a widespread nonessential heavy metal that enters the aquatic environment as a result of natural processes and human activities such as wastewater production, agriculture, and mining. To determine the effects of Cd on organisms, we investigated its time- and dose-related effects on mRNA levels of heat shock protein 90 (HSP90) and metallothionein (MT) in the gill and digestive gland and changes enzyme levels in the hemolymph of the Pacific oyster Crassostrea gigas. Full-length HSP90 cDNA was isolated from C. gigas by rapid amplification of cDNA end (RACE) techniques and found to contain 2154 nucleotides, including an open reading frame, and was predicted to encode a protein of 717 amino acids. BLAST analysis indicated that the HSP90 gene of C. gigas shared high homology with known HSP90 genes of other mollusks. The expression of HSP90 mRNA increased significantly with exposure to 0.01 ppm Cd for 11 days or 0.05 or 0.1 ppm Cd for 7 days. The expression of MT mRNA increased significantly with exposure to 0.01, 0.05, or 0.1 ppm Cd for 11 days. Glutamate oxaloacetate and glutamate pyruvate levels increased significantly with exposure to 0.05 or 0.1 ppm Cd for 7 days. These results indicate that HSP90 and MT play important roles in the physiological changes related to metabolism and cell protection that occur in Pacific oysters exposed to Cd.
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Affiliation(s)
- Yong Ki Choi
- Division of Marine Environment & Bioscience, Korea Maritime University, Busan, 606-791, South Korea
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Palomino A, González-Pinto A, Aldama A, González-Gómez C, Mosquera F, González-García G, Matute C. Decreased levels of plasma glutamate in patients with first-episode schizophrenia and bipolar disorder. Schizophr Res 2007; 95:174-8. [PMID: 17630258 DOI: 10.1016/j.schres.2007.06.012] [Citation(s) in RCA: 42] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Revised: 06/12/2007] [Accepted: 06/14/2007] [Indexed: 11/27/2022]
Abstract
A variety of studies have suggested that glutamatergic neurotransmission is altered in schizophrenia and bipolar disorder. Here, we tested if plasma glutamate levels are altered in 56 patients diagnosed with schizophrenia, bipolar disorder or non-specified psychosis at the first psychotic episode and at various stages during one-year follow-up. A decrease in the levels of plasma glutamate was observed in all groups of patients at the first psychotic episode. Furthermore, plasma glutamate levels were restored after treatment in all instances. Decreased plasma glutamate levels at first psychotic episodes may reflect impaired glutamate signaling during the initial stages of schizophrenia and bipolar disorder.
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Affiliation(s)
- Aitor Palomino
- Neurotek UPV-EHU, Parque Tecnológico de Bizkaia, E-48170 Zamudio, Vizcaya, Spain
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Akagawa M, Sasaki D, Ishii Y, Kurota Y, Yotsu-Yamashita M, Uchida K, Suyama K. New method for the quantitative determination of major protein carbonyls, alpha-aminoadipic and gamma-glutamic semialdehydes: investigation of the formation mechanism and chemical nature in vitro and in vivo. Chem Res Toxicol 2006; 19:1059-65. [PMID: 16918245 DOI: 10.1021/tx060026p] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [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: 11/29/2022]
Abstract
Alpha-aminoadipic semialdehyde (AAS) and gamma-glutamic semialdehyde (GGS) are identified as the major carbonyl products in oxidized proteins. To elucidate the formation pathway of AAS and GGS in vivo, we developed and validated a new quantification method. AAS and GGS in proteins were derivatized by reductive amination with NaCNBH(3) and p-aminobenzoic acid, a fluorescent reagent, followed by acid hydrolysis. It is noteworthy that the fluorescent derivatives were completely stable during acid hydrolysis. The present method permitted the specific, accurate, and sensitive quantification of both semialdehydes by fluorometric high-performance liquid chromatography. Analysis of proteins oxidized by various oxidation systems revealed that AAS and GGS are notably generated by the reaction of proteins with (*)OH, which is produced by metal-catalyzed oxidation (MCO). Furthermore, exposure of transferrin and human plasma to ascorbic acid and H(2)O(2) significantly promoted the formation of AAS and GGS in vitro, suggesting that both semialdehydes can be generated by MCO in vivo. We also demonstrated their generation through oxidative stress induced by acute iron overload in vivo. In this paper, we describe this analytical technique for simple and precise measurement of AAS and GGS and discuss their formation mechanism in vivo.
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Affiliation(s)
- Mitsugu Akagawa
- Department of Biological Chemistry, Division of Applied Life Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai 599-8531, Japan.
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Shulman Y, Grant S, Seres P, Hanstock C, Baker G, Tibbo P. The relation between peripheral and central glutamate and glutamine in healthy male volunteers. J Psychiatry Neurosci 2006; 31:406-10. [PMID: 17136218 PMCID: PMC1635795] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
OBJECTIVE High-field strength proton magnetic resonance spectroscopy ((1)H-MRS) and peripheral blood analyses reported in the literature reveal glutamate (Glu) and glutamine (Gln) abnormalities in schizophrenia. Given the relative ease and feasibility of using peripheral measures, the present study investigates the relation between peripheral and brain Glu and Gln levels. METHODS We recruited healthy volunteers (n = 17, mean age 21.9 [standard deviation 2.9, range 18-29] yr) between May and December 2005. All participants underwent 3 Tesla (1)H-MRS analysis with segmentation (grey matter, white matter, cerebrospinal fluid) at the Nuclear Magnetic Resonance Centre at the University of Alberta Hospital to quantify medial prefrontal cortical (mPFC) Glu and Glx (i.e., combination of Glu and Gln). Within 1 week of (1)H-MRS analysis, we collected plasma from the same participants for Glu and Gln quantification, using high-performance liquid chromatography at the Neurochemical Research Unit at the University of Alberta. RESULTS There was no correlation between plasma Glu and either medial prefrontal cortical Glu or Glx (R(1,15) = 0.019, p = 0.944 and R(1,15) = 0.081, p = 0.757, respectively). Similarly, there was no correlation between plasma Gln and either mPFC Glu or Glx (R(1,15) = 0.029, p = 0.911 and R(1,15) = 0.025, p = 0.925, respectively). CONCLUSION Our findings support the use of (1)H-MRS, instead of peripheral blood analysis, for investigating glutamatergic dysfunction in the brain.
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Affiliation(s)
- Yanina Shulman
- Centre for Neuroscience, University of Alberta, Edmonton, Canada
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Hendricksen K, Moonen PMJ, van der Heijden AG, Molkenboer-Kuenen J, Hulsbergen-van de Kaa CA, Witjes JA. Potential and toxicity of intravesical pemetrexed: a preclinical study in pigs. Clin Cancer Res 2006; 12:2597-601. [PMID: 16638871 DOI: 10.1158/1078-0432.ccr-05-2644] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE In search for a new drug for intravesical use in superficial urothelial cell carcinoma of the bladder, a pig model is used for pharmacokinetics and toxicity measurements after intravesically administered pemetrexed. EXPERIMENTAL DESIGN In the dose escalation phase, two groups of two pigs received 5 and 10 mg/kg pemetrexed intravesically; four groups of three pigs received 15, 20, 25, and 30 mg/kg, respectively. The well-being of the animals was monitored. Blood was studied for pharmacokinetic analysis and signs of myelosuppression. Posttreatment urine samples were collected to measure the concentration of pemetrexed after instillation. Twenty-four hours posttreatment, the animals were cystectomized and sacrificed. Histopathologic examination of the bladder wall was done. In the second study phase, five pigs were instilled weekly with the maximum tested dose for 6 weeks. The same methods were applied. RESULTS All doses (5-30 mg/kg) in the first study phase were well tolerated, enabling the use of 30 mg/kg in the second study phase. In both study phases, the pigs' well-being was not influenced. Full blood counts showed no sign of myelosuppression. Systemic absorption was not observed. Urine pemetrexed concentrations remained almost unchanged. Histopathologic examination of the bladder wall did not reveal significant abnormalities. Bladder mucosa remained intact at any time, without hemorrhage. CONCLUSIONS Intravesically administered pemetrexed in pigs is well tolerated, not absorbed systemically, and causes no bladder wall toxicity.
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Affiliation(s)
- Kees Hendricksen
- Departments of Urology and Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Mita AC, Sweeney CJ, Baker SD, Goetz A, Hammond LA, Patnaik A, Tolcher AW, Villalona-Calero M, Sandler A, Chaudhuri T, Molpus K, Latz JE, Simms L, Chaudhary AK, Johnson RD, Rowinsky EK, Takimoto CH. Phase I and Pharmacokinetic Study of Pemetrexed Administered Every 3 Weeks to Advanced Cancer Patients With Normal and Impaired Renal Function. J Clin Oncol 2006; 24:552-62. [PMID: 16391300 DOI: 10.1200/jco.2004.00.9720] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [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: 01/09/2023] Open
Abstract
Purpose This phase I study was conducted to determine the toxicities, pharmacokinetics, and recommended doses of pemetrexed in cancer patients with normal and impaired renal function. Patients and Methods Patients received a 10-minute infusion of 150 to 600 mg/m2 of pemetrexed every 3 weeks. Patients were stratified for independent dose escalation by measured glomerular filtration rate (GFR) into four cohorts ranging from ≥ 80 to less than 20 mL/min. Pemetrexed plasma and urine pharmacokinetics were evaluated for the first cycle. Patients enrolled after December 1999 were supplemented with oral folic acid and intramuscular vitamin B12. Results Forty-seven patients were treated with 167 cycles of pemetrexed. Hematologic dose-limiting toxicities occurred in vitamin-supplemented patients (two; 15%) and nonsupplemented patients (six; 18%), and included febrile neutropenia (four patients) and grade 4 thrombocytopenia (two patients). Nonhematologic toxicities included fatigue, diarrhea, and nausea, and did not correlate with renal function. Accrual was discontinued in patients with GFR less than 30 mL/min after one patient with a GFR of 19 mL/min died as a result of treatment-related toxicities. Pemetrexed plasma clearance positively correlated with GFR (r2 = 0.736), resulting in increased drug exposures in patients with impaired renal function. With vitamin supplementation, pemetrexed 600 mg/m2 was tolerated by patients with a GFR ≥ 80 mL/min, whereas patients with a GFR of 40 to 79 mL/min tolerated a dose of 500 mg/m2. Conclusion Pemetrexed was well tolerated at doses of 500 mg/m2 with vitamin supplementation in patients with GFR ≥ 40 mL/min. Additional studies are needed to define appropriate dosing for renally impaired patients receiving higher dose pemetrexed with vitamin supplementation.
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Affiliation(s)
- Alain C Mita
- Institute for Drug Development, Cancer Therapy and Research Center, San Antonio, TX, 78229, USA
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Sokoro AAH, Etter ML, Lepage J, Weist B, Eichhorst J, Lehotay DC. Simple method for the quantitative analysis of endogenous folate catabolites p-aminobenzoylglutamate (pABG) and its acetamido (apABG) derivative in human serum and urine by liquid chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 832:9-16. [PMID: 16427369 DOI: 10.1016/j.jchromb.2005.11.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Revised: 11/21/2005] [Accepted: 11/30/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To develop a routine method for quantitative measurement of the folate catabolites p-aminobenzoylglutamate (pABG) and acetamidobenzoylglutamate (apABG) in serum and urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). DESIGN AND METHODS Urine, serum and aqueous standards were thawed. Two microliters of d3-glutamic acid (d3-Glu; 1 mmol/L) was added to 200 uL of specimen as internal standard. The samples were acidified with 4 uL 6N HCL, and aliquots were precipitated with 2 volumes (412 uL) of acetonitrile. For urine specimens 30 volumes (6.18 mL) of acetonitrile was used. Samples were centrifuged at 1900 x g for 10 min and the supernatant (10 microL) injected into a Biorad CAT/MET analytical column fitted to the LC-MS/MS. Detection of the catabolites was by selective multiple ion monitoring (multiple SRM) of the respective transitions. Urine and serum samples were analysed in a group of healthy volunteers and in anonymous samples from patients being tested for PTH and urinary catecholamines. RESULTS pABG and apABG eluted at 5.2 and 4.74 min, respectively while the d3-glutamic acid eluted at around 7 min. Limit of quantitation (LOQ) for both catabolites was 10 nmol/L (which is equivalent to 33.3 fmol for a 10 microL injection). Limit of detection (LOD) was 1 nmol/L based on a signal to noise ratio of 5:1. A linear calibration curve was obtained from 10 to 100 nmol/L for serum specimens and from 10 to 200 micromol/L for urines. Imprecision for spiked serum samples (n=10) was between 2.5 and 20% for apABG and 4.5 and 21% for pABG (at 10 and 100 nmol/L, respectively). Imprecision for spiked urine samples (n=10) was between 2.9 and 4.0% for apABG and 6.0-12.7% for pABG. Recoveries were between 80 and 122% for serum samples and between 92 and 102% for urine specimens. Total folate catabolites in random urine samples from volunteers (n=5) are 2.9+/-2.3 umol/L (mean+/-S.D.). This group also had total serum catabolites of 11.9+/-7.6 nmol/L and serum folate of 35.3+/-5.8 nmol/L. Serum from patients being tested for PTH (n=11) had serum folate levels of 27.0+/-10.4 nmol/L with total serum catabolites of 20.4+/-23.8 nmol/L. Levels of serum folate and total catabolites in pregnant women (n=18) were 33.9+/-22.7 and 11.4+/-8.7 nmol/L, respectively. Mean urinary folate catabolites in patients being tested for urinary catecholamines (n=19) was 581.8+/-368.4 nmol/L. CONCLUSION A simple, reliable and highly specific method by LC-MS/MS for detecting and quantifying the folate catabolites pABG and apABG was developed. This enables, for the first time, the routine clinical analysis of folate utilization in patients.
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Affiliation(s)
- A A H Sokoro
- The Provincial Laboratory, Saskatchewan Health, 3211 Albert Street, Regina, SK, Canada S4S 5W6
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16
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Abstract
Theanine, first discovered in tea, is a chiral nonproteinic amino acid that has been reported to have cardiovascular, neurological, and oncological effects. It is being considered as a therapeutic/medicinal agent and additive in consumer products. The present study evaluated the pharmacokinetics of D-theanine, L-theanine, and D,L-theanine in plasma and urine using LC-ESI/MS in rats after oral (p.o.) and intraperitoneal (i.p.) administration. Oral administration data indicated that gut absorption of d-theanine was far less than that of L-theanine. However, after i.p. administration, plasma theanine concentrations of L- and D-theanine were similar. This indicated that D- and L-theanine may exhibit a competitive effect with respect to intestinal absorption. Regardless of the route of administration, p.o. or i.p., the presence of the other enantiomer always decreased theanine plasma concentrations, indicating D,L-theanine competition with respect to urinary reabsorption. Data on urinary concentrations of D-theanine suggested that the D-isomer may be eliminated with minimal metabolism. L-Theanine appeared to be preferentially reabsorbed and metabolized by the kidney while D-theanine was preferentially excreted. Clearly, the bioequivalencies of D,L-theanine and its enantiomers were found to be quite different from one another. Consequently, the efficacy of commercial theanine products containing D-theanine, L-theanine, or D,L-theanine may be quite different.
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Affiliation(s)
- Meera J Desai
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
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17
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van der Heijden FMMA, Tuinier S, Fekkes D, Sijben AES, Kahn RS, Verhoeven WMA. Atypical antipsychotics and the relevance of glutamate and serotonin. Eur Neuropsychopharmacol 2004; 14:259-65. [PMID: 15056486 DOI: 10.1016/j.euroneuro.2003.09.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [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] [Received: 02/24/2003] [Indexed: 11/20/2022]
Abstract
In the present study, including 66 schizophrenic patients and 73 healthy controls, the effect of atypical antipsychotic treatment over a period of 14 weeks on psychotic symptoms and plasma levels of glutamate and monoaminergic metabolites was investigated. Treatment induced a modest reduction of psychotic symptoms in 42% of the patients (response criterion: Brief Psychiatric Rating Scale [BPRS] decrease >/=40%). Poor response was associated with severity of psychopathology, age and duration of disease. Glutamate at baseline was significantly higher in patients as compared to controls (p<0.01). During treatment, a significant further increase of glutamate, not related to response, was observed. Glutamate levels correlated significantly with negative symptom scores at baseline and weeks 3, 6 and 14 (p<0.05). At baseline, serotonin (5-HT) in plasma and 5-HT in platelets were significantly lower in the poor responders as compared to controls (p<0.05) and increased significantly during treatment (p<0.05). In the responders, treatment coincided with a decrease of 5-HT parameters. No differences in plasma levels of HVA, 5-HIAA and their ratio were observed between controls and response groups. The results of this study suggest an effect of atypical antipsychotics on glutamatergic neurotransmission and an association between lower pretreatment peripheral 5-HT parameters and response.
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18
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Manivasagam T, Subramanian P. Monosodium glutamate affects the temporal characteristics of biochemical variables in Wistar rats. Pol J Pharmacol 2004; 56:79-84. [PMID: 15047981] [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] [Subscribe] [Scholar Register] [Received: 05/08/2003] [Revised: 12/15/2003] [Indexed: 04/29/2023]
Abstract
Monosodium glutamate (MSG) was administrated chronically for 60 days to Wistar rats and 24 h rhythms of glucose, cholesterol, total protein and alkaline phosphatase were studied. MSG treatment was found to cause acrophase delays in the glucose and alkaline phosphatase rhythms and advances in acrophases of cholesterol and total protein levels. Amplitude and mesor values of these rhythms were found to be altered during MSG treatment. Glutamate levels in the brain were found to be significantly increased, which could alter these biochemical rhythms by modulating the transmission in retinohypothalamic tract and in the hypothalamic nuclei, probably including suprachiasmatic nuclei.
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Affiliation(s)
- Thamilarasan Manivasagam
- Department of Biochemistry, Faculty of Science, Annamalai University, Annamalainagar-608 002, Tamil Nadu, India
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19
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Reynolds JD, Amory DW, Grocott HP, White WD, Newman MF. Change in plasma glutamate concentration during cardiac surgery is a poor predictor of cognitive outcome. J Cardiothorac Vasc Anesth 2002; 16:431-6. [PMID: 12154420 DOI: 10.1053/jcan.2002.125148] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To develop a simple and reliable method for quantitating plasma glutamate concentration and apply this method to monitor systemic glutamate levels during coronary artery bypass graft (CABG) surgery, a procedure associated with neurologic deficits. DESIGN Prospective serial investigation of cardiac surgery patients. SETTING Tertiary-care university teaching hospital. PARTICIPANTS Patients undergoing CABG surgery (n = 33). INTERVENTIONS Preoperative and postoperative neurologic and neurocognitive testing were done. Intraoperative blood samples for glutamate quantitation were obtained from jugular bulb and pulmonary artery catheters before, during, and after cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS Glutamate concentrations were determined using a reverse-phase high-pressure liquid chromatography method coupled to precolumn derivatization of the analyte with o-phthalaldehyde. The mean prebypass plasma glutamate concentration was 79.4 +/- 41.8 micromol/L. Plasma glutamate levels fluctuated during surgery with considerable degrees of temporal and quantitative interpatient variability. Neurologic and neurocognitive deficits were observed after CABG surgery. However, neither the occurrence nor the severity of cognitive decline could be predicted by the magnitude of increase in plasma glutamate concentration. CONCLUSION Fluctuations in intraoperative systemic glutamate levels do not predict post-CABG surgery neurologic outcome.
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Affiliation(s)
- James D Reynolds
- Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA.
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20
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Rivory LP, Clarke SJ, Boyer M, Bishop JF. Highly sensitive analysis of the antifolate pemetrexed sodium, a new cancer agent, in human plasma and urine by high-performance liquid chromatography. J Chromatogr B Biomed Sci Appl 2001; 765:135-40. [PMID: 11767306 DOI: 10.1016/s0378-4347(01)00406-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A reversed-phase high-performance liquid chromatography method was developed and validated for the quantitation of pemetrexed (LY231514, ALIMTA) in human urine and plasma. Plasma samples were spiked with the internal standard lometrexol and extracted using Certify II columns. Pemetrexed was assayed in diluted urine by an external calibration method. A C8 column was used for the separation of analytes with a mobile phase composed of sodium formate buffer and acetonitrile. Between- and within-day precision and accuracy were acceptable down to the limit of quantitation of 5 ng/ml in plasma. This method was used successfully for an investigation of the disposition of pemetrexed in patients receiving 500 mg/m2 as a 10-min infusion.
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Affiliation(s)
- L P Rivory
- Sydney Cancer Centre, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
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21
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Gregory JF, Caudill MA, Opalko FJ, Bailey LB. Kinetics of folate turnover in pregnant women (second trimester) and nonpregnant controls during folic acid supplementation: stable-isotopic labeling of plasma folate, urinary folate and folate catabolites shows subtle effects of pregnancy on turnover of folate pools. J Nutr 2001; 131:1928-37. [PMID: 11435509 DOI: 10.1093/jn/131.7.1928] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [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: 11/15/2022] Open
Abstract
To investigate the effects of pregnancy on folate metabolism, we conducted an 84-d study in second-trimester (gestational wk 14-25) pregnant women (n = 6) and nonpregnant controls (n = 6) with stable-isotopic tracer methods. All subjects were fed a diet containing approximately 272 nmol/d (120 microg/d) folate from food, along with supplemental folic acid that contained 15% [3',5'-(2)H(2)] folic acid ([(2)H(2)]folic acid) during d 1--41 and that was unlabeled during d 42--84 to yield a constant total folate intake of 1.02 or 1.93 micromol/d (450 or 850 microg/d). Isotopic enrichment of plasma folate, urinary folate and the urinary folate catabolites para-aminobenzoylglutamate (pABG) and para-acetamidobenzoylglutamate (ApABG) was determined at intervals throughout the study. The labeling of pABG and ApABG reflected that of tissue folate pools from which the catabolites originate. After the intake of labeled folic acid was terminated on d 41, labeling of urinary folate exhibited a biphasic exponential decline with distinct fast and slow components. In contrast, during d 42--84, the enrichment of urinary pABG and ApABG exhibited primarily monophasic exponential decline, and plasma folate underwent little decline of labeling during this period. Pregnant women and controls did not differ in estimates of body folate pool size and most aspects of the excretion of labeled urinary folate and catabolites, rates of decline of excretion, and areas under the curves for folate and catabolite excretion. Pregnant women, however, tended to have a slower rate of decline of pABG than ApABG and higher enrichment at d 42 of ApABG and pABG. These data support and extend our previous findings indicating that pregnancy (gestational wk 14--26) causes subtle changes in folate metabolism but does not elicit substantial increases in the rate or extent of folate turnover at these moderately high folate intakes.
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Affiliation(s)
- J F Gregory
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL 32611-0370, USA.
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22
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Perrault LP, Nickner C, Desjardins N, Dumont E, Thai P, Carrier M. Improved preservation of coronary endothelial function with Celsior compared with blood and crystalloid solutions in heart transplantation. J Heart Lung Transplant 2001; 20:549-58. [PMID: 11343982 DOI: 10.1016/s1053-2498(01)00242-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [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: 11/26/2022] Open
Abstract
BACKGROUND Endothelial injury from preservation solutions has been implicated in acute coronary vasospasm and pathologic activation of the endothelium, which can contribute to the development of graft coronary vasculopathy after heart transplantation. Preservation solutions with a powerful antioxidant capacity may decrease the occurrence of these complications. MATERIALS AND METHODS This study was designed to evaluate the effect of Celsior (an anti-oxidant solution specifically designed for cardiac preservation) in a model of heart preservation (4 hours at 4 degrees C to reproduce the situation encountered in clinical heart transplantation) compared two commonly used cardioplegic and preservation strategies on coronary endothelial function. Endothelium-dependent relaxation of normal porcine epicardial coronary arteries to serotonin (5-HT, an agonist that activates 5-HT(1d) receptors coupled to Gi proteins) and bradykinin (BK, which activates B2 receptors coupled to Gq proteins) was studied in standard organ chamber experiments in the following groups: a control group was submitted to immediate excision without cardioplegia and preserved in saline solution (0.9% NaCl) for 4 hours (Group 1); two groups had cardioplegia induced with a crystalloid solution and were stored for 4 hours in saline (Group 2) or 4 hours in Celsior solution (Group 3); and two groups had cardioplegia induced with normothermic blood cardioplegia and were stored for 4 hours in the saline (Group 4), or 4 hours in Celsior solution (Group 5). Finally, two groups underwent cardioplegia with Celsior and were stored for 4 hours in saline (Group 6), or 4 hours in the Celsior solution (Group 7). All cardioplegia solutions were at 4 degrees C (except blood cardioplegia at 37 degrees C) and all preservations solutions were at 4 degrees C. RESULTS Endothelium-dependent relaxations to serotonin were significantly decreased in all groups except the Celsior + Celsior group compared with the control group. There were no significant differences in relaxation to bradykinin except in one group. Use of the Celsior solution for induction of cardioplegia and storage better preserved endothelium-dependent G-protein-mediated relaxation compared with the other arrest and preservation strategies. CONCLUSIONS The observed effect may be associated with an improvement in both short- and long-term outcome in heart transplantation, especially because these alterations may be further compounded by reperfusion.
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Affiliation(s)
- L P Perrault
- Research Center, Department of Surgery, Montreal Heart Institute, Quebec, Canada.
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23
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Abstract
Dysregulation of glutamate has been described in depression, and supersensitivity of platelet glutamate receptors has been found in both psychotic major depression and schizophrenia. The aim of this study was to examine the platelet glutamate receptor sensitivity in patients with nonpsychotic, unipolar major depression to assess whether this is a marker of depression or of psychosis. Glutamate receptor sensitivity was assessed using the platelet intracellular calcium response to glutamate (0-100 micromol) measured by spectrofluorometry. The depression group showed a significantly greater platelet intracellular calcium response to glutamate stimulation than the control group, both in terms of absolute values (p = 0.007) and percentage of response from baseline (p = 0.030). These data suggest that platelet glutamate receptors may be supersensitive in depression and that the platelet may be a possible peripheral marker of glutamate function in depression.
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Affiliation(s)
- M Berk
- Department of Psychiatry, University of the Witwatersrand, Johannesburg, South Africa
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24
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Ouellet D, Periclou AP, Johnson RD, Woodworth JR, Lalonde RL. Population pharmacokinetics of pemetrexed disodium (ALIMTA) in patients with cancer. Cancer Chemother Pharmacol 2000; 46:227-34. [PMID: 11021740 DOI: 10.1007/s002800000144] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [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: 10/27/2022]
Abstract
PURPOSE To evaluate the population pharmacokinetics of pemetrexed disodium in cancer patients enrolled in four different open-label, multicenter, nonrandomized phase II studies. METHODS Pemetrexed disodium was administered as a 10-min intravenous infusion (600 mg/m2) every 21 days. A total of four blood samples were to be collected each cycle per patient (n= 103 patients) during cycles 1 and 3. Plasma concentration-time data were analyzed by nonlinear mixed-effect modeling using NONMEM to estimate pemetrexed disodium pharmacokinetic parameters (mean, and between- and within-patient variability) as well as relationships between the pharmacokinetic parameters and various patient-specific factors (demographic and physiologic data). RESULTS/CONCLUSIONS The pharmacokinetics of pemetrexed disodium were best characterized by a two-compartment model with initial distribution and terminal elimination half-lives of 0.63 h and 2.73 h, respectively. The typical value of systemic clearance (CL) in liters per hour included a relationship to creatinine clearance (CrCL) with a slope of 0.0292. Typical values of central volume (V(c)), distributional CL (Q), and peripheral volume (V(p)) were 11.3 1, 3.21 l/h, and 5.20 l, respectively. Between-patient variability was 19.6%, 15.6%, and 21.7% for CL, V(c), and V(p), respectively. A combined additive/proportional error model was used to describe residual variability, with a coefficient of variation of 23.7% for the proportional component and a standard deviation of 0.0410 microg/ml for the additive component. Significant patient-specific factors on CL were calculated CrCL, body weight, and to a lesser extent alanine transaminase and folate deficiency. Gender and body weight were significant factors on V(c) while both body surface area and albumin were significant factors on V(p). In conclusion, population pharmacokinetic modeling revealed relationships between pharmacokinetic parameters and various patient specific factors.
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Affiliation(s)
- D Ouellet
- Phoenix International Life Sciences Inc, Saint-Laurent, Québec, Canada
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25
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Ferrarese C, Begni B, Canevari C, Zoia C, Piolti R, Frigo M, Appollonio I, Frattola L. Glutamate uptake is decreased in platelets from Alzheimer's disease patients. Ann Neurol 2000; 47:641-3. [PMID: 10805335] [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: 02/16/2023]
Abstract
Because excitotoxicity may be involved in neurodegeneration in Alzheimer's disease, we investigated possible modifications of platelet glutamate uptake in AD patients. High-affinity glutamate uptake was studied in platelets from 35 Alzheimer's disease patients, 10 multi-infarct dementia patients, and 35 age-matched normal controls; it was decreased by 40% in platelets from Alzheimer's disease patients compared with controls and with multi-infarct dementia patients. Platelet glutamate uptake could be used as peripheral marker of glutamatergic involvement and as adjunctive diagnostic tool in Alzheimer's disease patients.
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Affiliation(s)
- C Ferrarese
- Department of Neurology, University of Milano-Bicocca, Ospedale San Gerardo, Monza, Italy
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26
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Yamato O, Lee KW, Chang HS, Tajima M, Maede Y. Relation between erythrocyte reduced glutathione and glutamate concentrations in Korean Jindo dogs with erythrocytes possessing hereditary high activity of Na-K-ATPase and a high concentration of potassium. J Vet Med Sci 1999; 61:1179-82. [PMID: 10563301 DOI: 10.1292/jvms.61.1179] [Citation(s) in RCA: 9] [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: 11/22/2022] Open
Abstract
The concentrations of sodium, potassium, reduced glutathione (GSH) and free amino acids and Na-K-ATPase activity in erythrocytes were examined in 35 purebred Jindo dogs in Korea. The incidence of Jindo dogs with a high potassium concentration and high activity of Na-K-ATPase in erythrocytes (HK phenotype) was 25.7%. The erythrocyte GSH concentration in HK Jindo dogs varied widely, from 2.45 to 12.38 mmol/l of RBCs, and was positively correlated with the erythrocyte glutamate concentration. These results indicate that HK Jindo dogs have normal to very high levels of erythrocyte GSH, which might result from the varying quantity of Na-dependent glutamate influx in the erythrocytes.
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Affiliation(s)
- O Yamato
- Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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27
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Abstract
The metabolism of theanine, one of the major amino acid components in tea (Camellia sinensis), was studied in rats. High-performance liquid chromatography (HPLC) with fluorometric detection was used to evaluate the nature of theanine's metabolites in plasma, urine, and tissues. In the urine samples collected after administration of 100, 200, and 400 mg each of theanine, intact theanine, L-glutamic acid, and ethylamine, these compounds were detected in a dose-dependent manner. When 200 mg of theanine was orally administered to rats, the plasma concentrations of theanine and ethylamine reached their highest levels about 0.5 and 2 h after administration, respectively. It seems most likely that the enzymatic hydrolysis of theanine to glutamic acid and ethylamine was accomplished in the kidney. These results indicate that orally administered theanine is absorbed through the intestinal tract and hydrolyzed to glutamic acid and ethylamine in the rat kidney.
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Affiliation(s)
- T Unno
- Central Research Institute, Itoen Ltd., Sagara-cho, Haibara-gun, Shizuoka, Japan.
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28
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Chesnokova EA, Sariev AK, Zherdev VP, Kartashov VS, Smirnov LD. [The bioavailability of tableted drug forms of the new Russian nootropic preparation nooglutil in rabbits]. Eksp Klin Farmakol 1998; 61:48-50. [PMID: 9783110] [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] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Comparative study of the main pharmacokinetic characteristics and evaluation of the bioavailability of two experimental tablet forms of the new nootropic nooglutil in relation to the substance of the drug were conducted on rabbits. The nooglutil content in plasma samples was determined by high performance liquid chromatography. Significant advantage of one tablet of the drug containing tween-80 was demonstrated. Bioavailability of this drug form of nooglutil in relation to the substance of the drug was 104.3%.
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Affiliation(s)
- E A Chesnokova
- Laboratory of Pharmacokinetics, Russian Academy of Medical Sciences, Moscow, Russia
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29
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Wagner KR, Xi G, Hua Y, Kleinholz M, de Courten-Myers GM, Myers RE. Early metabolic alterations in edematous perihematomal brain regions following experimental intracerebral hemorrhage. J Neurosurg 1998; 88:1058-65. [PMID: 9609301 DOI: 10.3171/jns.1998.88.6.1058] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.5] [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: 02/07/2023]
Abstract
OBJECT The authors previously demonstrated, in a large-animal intracerebral hemorrhage (ICH) model, that markedly edematous ("translucent") white matter regions (> 10% increases in water contents) containing high levels of clot-derived plasma proteins rapidly develop adjacent to hematomas. The goal of the present study was to determine the concentrations of high-energy phosphate, carbohydrate substrate, and lactate in these and other perihematomal white and gray matter regions during the early hours following experimental ICH. METHODS The authors infused autologous blood (1.7 ml) into frontal lobe white matter in a physiologically controlled model in pigs (weighing approximately 7 kg each) and froze their brains in situ at 1, 3, 5, or 8 hours postinfusion. Adenosine triphosphate (ATP), phosphocreatine (PCr), glycogen, glucose, lactate, and water contents were then measured in white and gray matter located ipsi- and contralateral to the hematomas, and metabolite concentrations in edematous brain regions were corrected for dilution. In markedly edematous white matter, glycogen and glucose concentrations increased two- to fivefold compared with control during 8 hours postinfusion. Similarly, PCr levels increased several-fold by 5 hours, whereas, except for a moderate decrease at 1 hour, ATP remained unchanged. Lactate was markedly increased (approximately 20 micromol/g) at all times. In gyral gray matter overlying the hematoma, water contents and glycogen levels were significantly increased at 5 and 8 hours, whereas lactate levels were increased two- to fourfold at all times. CONCLUSIONS These results, which demonstrate normal to increased high-energy phosphate and carbohydrate substrate concentrations in edematous perihematomal regions during the early hours following ICH, are qualitatively similar to findings in other brain injury models in which a reduction in metabolic rate develops. Because an energy deficit is not present, lactate accumulation in edematous white matter is not caused by stimulated anaerobic glycolysis. Instead, because glutamate concentrations in the blood entering the brain's extracellular space during ICH are several-fold higher than normal levels, the authors speculate, on the basis of work reported by Pellerin and Magistretti, that glutamate uptake by astrocytes leads to enhanced aerobic glycolysis and lactate is generated at a rate that exceeds utilization.
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Affiliation(s)
- K R Wagner
- Department of Neurology, University of Cincinnati College of Medicine, Department of Veterans Affairs Medical Center, Ohio 45220, USA
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30
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McDonald AC, Vasey PA, Adams L, Walling J, Woodworth JR, Abrahams T, McCarthy S, Bailey NP, Siddiqui N, Lind MJ, Calvert AH, Twelves CJ, Cassidy J, Kaye SB. A phase I and pharmacokinetic study of LY231514, the multitargeted antifolate. Clin Cancer Res 1998; 4:605-10. [PMID: 9533527] [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: 02/07/2023]
Abstract
LY231514 is a novel antifolate that principally inhibits thymidylate synthase, but with additional folate-dependent enzyme targets. A Phase I study of single-agent LY231514 administered as a daily i.v. infusion over 10 minutes for 5 days, repeated every 3 weeks, was conducted to evaluate the maximum tolerated dose, pharmacokinetic profile, and antitumor activity of the drug using this schedule. Thirty-eight patients with advanced malignancies that were refractory or not amenable to standard therapy were treated with a total of 116 courses of LY231514, escalating treatment doses through 10 dose levels, from 0.2-5.2 mg/m2/day. No objective clinical responses were observed, although minor antitumor activity not fulfilling the response criteria was seen in three patients. A maximum tolerated dose of 4.0 mg/m2/day was determined, with neutropenia as the predominant dose-limiting toxicity. Reversible disturbances of liver biochemistry, fulfilling the protocol definitions of dose-limiting toxicity, were also observed. Other toxicities included diarrhea, mucositis, skin rash, and fatigue. Pharmacokinetic studies were performed at all treatment levels. Analysis showed a linear relation between administered dose and both maximum plasma concentration (Cmax) and area under the plasma concentration/time curve. The drug was cleared with a day 1 total body clearance of 108.9 +/- 38.8 ml/min/m2, with plasma concentrations declining with a mean harmonic terminal half-life of 1.4 +/- 0.98 h. When given by this schedule, LY231514 is tolerable, and Phase II studies are in progress.
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Affiliation(s)
- A C McDonald
- CRC Department of Medical Oncology, Beatson Oncology Centre, Glasgow, United Kingdom.
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Abstract
BACKGROUND Alpha-ketoglutarate (alpha-KG) is a Krebs cycle intermediate and the carbon skeleton of glutamate. Alpha-ketoglutarate has provoked interest in heart surgery because of its proposed critical role in myocardial metabolism. This study investigates the role of alpha-KG in renal function after cardiac surgical procedures. METHODS Twenty-two patients with normal preoperative renal function were included in a prospective, randomized, and controlled study. Eleven patients received intravenous infusion of 30 g alpha-KG/hour after the operation. Measurements were performed before operation, immediately after operation, and after 30 minutes of alpha-KG infusion. RESULTS Renal blood flow was higher during alpha-KG infusion, 297% +/- 97% (of preoperative value), than in controls, 125% +/- 20% (p < 0.05). Filtration fraction was lower (12.3% +/- 0.05% versus 17.2% +/- 1.1%, p < 0.01), which prevented a significant difference in glomerular filtration rate. The renal arteriovenous differences of lactate, glutamate, glutamine, and glycine changed toward a net release during alpha-KG infusion. CONCLUSIONS Infusion of alpha-KG enhances renal blood flow early after coronary surgical procedures in patients with normal renal function. The mechanism is unclear, but could be associated with primarily metabolic effects, and may potentially convey a beneficial effect for renal function.
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Affiliation(s)
- A Jeppsson
- Department of Thoracic and Cardiovascular Surgery, Sahlgrenska University Hospital, Göteborg, Sweden
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32
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Divino Filho JC, Hazel SJ, Fürst P, Bergström J, Hall K. Glutamate concentration in plasma, erythrocyte and muscle in relation to plasma levels of insulin-like growth factor (IGF)-I, IGF binding protein-1 and insulin in patients on haemodialysis. J Endocrinol 1998; 156:519-27. [PMID: 9582509 DOI: 10.1677/joe.0.1560519] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [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: 02/07/2023]
Abstract
Elevated insulin-like growth factor binding protein (IGFBP) levels, including IGFBP-1, occur in renal failure, and may contribute towards reduced IGF bioactivity in uraemia. The reduced IGF bioactivity may, in turn, contribute towards the disturbances in protein metabolism present in renal failure. In this study, the relationships between intra- and extracellular amino acid (AA) levels and IGF-I and/or IGFBP-1 levels were studied in 30 adult patients (aged 24-70 years) on haemodialysis who had no clinical signs of malnutrition. Blood samples (n = 30) and muscle biopsies (n = 13) were collected for determination of free AA in erythrocytes (RBC), plasma and muscle by reverse-phase HPLC while IGFBP-1, IGF-I and insulin plasma levels were determined by radioimmunoassay The patients on haemodialysis had elevated glutamate concentrations in RBC and plasma compared with healthy controls (524 +/- 26 vs 448 +/- 17 mumol/l, P < 0.05 and 45 +/- 4 vs 32 +/- 4 mumol/l, P < 0.01 respectively), although glutamate levels in muscle were within the normal range. The mean IGF-I level was slightly increased (s.d. score +0.74 +/- 0.30) but insulin levels were within the normal range. IGFBP-1 levels, which were inversely correlated to insulin (r = -0.40, P < 0.02), were elevated threefold compared with controls. No plasma AA level displayed a significant correlation with IGF-I, IGFBP-1 or insulin levels. However, glutamate concentrations in RBC were positively correlated to IGFBP-1 (r = 0.51, P < 0.01) and inversely correlated to IGF-I (r = -0.46. P < 0.01), although unrelated to insulin. Muscle glutamate, which was inversely related to RBC glutamate, displayed an opposite pattern with an inverse relation to IGFBP-1 levels (r = - 0.73, P < 0.01) and a positive correlation to IGF-I levels (r = 0.64, P < 0.02). Glutamate was the only AA to display an inverse correlation between RBC and muscle (r = -0.65, P < 0.02, n = 12). These findings lead us to propose that, in uraemia, the elevated IGFBP-I levels, which reduce the bioavailability of IGFs, are linked to glutamate uptake in muscle, resulting in accumulation of RBC glutamate. Whether there is a causal relationship or the correlation is due to some common regulator is not clarified in the present study.
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Affiliation(s)
- J C Divino Filho
- Division of Renal Medicine, Huddinge University Hospital, Karolinska Institute, Stockholm, Sweden
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33
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Ghomeshi HR, Tian G, Ye J, Sun J, Hoffenberg EF, Salerno TA, Deslauriers R. Aspartate/glutamate-enriched blood does not improve myocardial energy metabolism during ischemia-reperfusion: a 31P magnetic resonance spectroscopic study in isolated pig hearts. J Thorac Cardiovasc Surg 1997; 113:1068-77; discussion 1077-80. [PMID: 9202688 DOI: 10.1016/s0022-5223(97)70294-0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Our objective was to test the effects of exogenous L-aspartate and L-glutamate on myocardial energy metabolism during ischemia-reperfusion. METHODS Phosphorus 31-magnetic resonance spectroscopy was used to observe cellular energetics and intracellular pH in isolated pig hearts perfused with blood (group A, n = 8) or blood enriched with 13 mmol/L each of L-aspartate and L-glutamate (group B, n = 6). The hearts were subjected to 30 minutes of total normothermic ischemia and then reperfused for 40 minutes. Two hearts from each group were inotropically stimulated by titration with calcium after normokalemic reperfusion. Left ventricular function was measured with the use of a compliant balloon and oxygen consumption was calculated. RESULTS Magnetic resonance spectroscopy showed no decrease in the rate of energy decline during ischemia for group B versus group A. No significant differences were observed between the two groups in terms of myocardial function, oxygen consumption, or the rate or extent of high-energy phosphate recovery after normokalemic reperfusion or inotropic stimulation. Inotropic stimulation of postischemic hearts, however, led to dramatic improvement in myocardial function in both groups (p < 0.05 for all parameters) and significant improvement in oxygen consumption (p = 0.01). CONCLUSIONS In a normal, isolated, blood-perfused pig heart subjected to 30 minutes of total normothermic ischemia, (1) enrichment of the perfusate with aspartate/glutamate before and after ischemia affects neither myocardial energy metabolism during ischemia-reperfusion nor postischemic recovery of myocardial function or oxygen consumption and (2) inotropic stimulation can recruit significant postischemic function and sufficient aerobic respiration to support it, irrespective of aspartate/glutamate enrichment.
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Affiliation(s)
- H R Ghomeshi
- Institute for Biodiagnostic, National Research Council of Canada, Winnipeg, Manitoba, Canada
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34
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Perriello G, Nurjhan N, Stumvoll M, Bucci A, Welle S, Dailey G, Bier DM, Toft I, Jenssen TG, Gerich JE. Regulation of gluconeogenesis by glutamine in normal postabsorptive humans. Am J Physiol 1997; 272:E437-45. [PMID: 9124550 DOI: 10.1152/ajpendo.1997.272.3.e437] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
There is evidence that glutamine may act as a regulator of protein, free fatty acid, and glycogen metabolism. To test the hypothesis that glutamine may act as a physiological regulator of gluconeogenesis, we infused 16 normal postabsorptive volunteers with glutamine at a rate (11.4 micromol kg(-1) x min(-1)) estimated to approximate its appearance in plasma after a protein meal and assessed changes in production of glucose from glutamine, systemic glucose appearance and disposal, and uptake and release of glucose, glutamine, and alanine by forearm skeletal muscle. Although infusion of glutamine increased plasma glutamine concentration and turnover only threefold (from 0.63 +/- 0.03 to 1.95 +/- 0.10 mmol/l and from 5.43 +/- 0.24 to 14.85 +/- 0.66 micromol x kg(-1) x min(-1), respectively; P < 0.001), formation of glucose from glutamine increased sevenfold from 0.55 +/- 0.03 to 3.74 +/- 0.28 micromol x kg(-1) x min(-1) (P < 0.001). Formation of glucose from alanine was also stimulated (0.52 +/- 0.05 vs. 0.75 +/- 0.04 micromol x kg(-1) x min(-1); P < 0.001) in the absence of a change in plasma alanine concentration. Furthermore, glutamine infusion decreased its own de novo synthesis (4.55 +/- 0.22 vs. 2.81 +/- 0.62 micromol x kg(-1) x min(-1);P < 0.02) while increasing that of alanine (2.82 +/- 0.32 vs. 3.56 +/- 0.32 micromol x kg(-1) x min(-1); P < 0.002). Systemic glucose appearance, systemic glucose disposal, and forearm balance of glucose and alanine were not altered. Because the stimulatory effects of glutamine on gluconeogenesis occurred in the absence of changes in plasma insulin and glucagon levels, these results provide evidence that, in humans, glutamine may act both as a substrate and as a regulator of gluconeogenesis as well as a modulator of its own metabolism.
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Affiliation(s)
- G Perriello
- The University of Rochester School of Medicine, New York 14642, USA
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35
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Hack V, Stütz O, Kinscherf R, Schykowski M, Kellerer M, Holm E, Dröge W. Elevated venous glutamate levels in (pre)catabolic conditions result at least partly from a decreased glutamate transport activity. J Mol Med (Berl) 1996; 74:337-43. [PMID: 8862515 DOI: 10.1007/bf00207511] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [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: 02/02/2023]
Abstract
Abnormally high postabsorptive venous plasma glutamate levels have been reported for several diseases that are associated with a loss of body cell mass including cancer, human/simian immunodeficiency virus infection, and amyotrophic lateral sclerosis. Studies on exchange rates in well-nourished cancer patients now show that high venous plasma glutamate levels may serve as a bona fide indicator for a decreased uptake of glutamate by the peripheral muscle tissue in the postabsorptive period and may be indicative for a precachectic state. High glutamate levels are also moderately correlated with a decreased uptake of glucose and ketone bodies. Relatively high venous glutamate levels have also been found in non-insulin-dependent diabetes mellitus and to some extent also in the cubital vein of normal elderly subjects, i.e., in conditions commonly associated with a decreased glucose tolerance and progressive loss of body cell mass.
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Affiliation(s)
- V Hack
- Department of Immunochemistry, Deutsches Krebsforschungszentrum, Heidelberg, Germany
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36
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Aukrust P, Svardal AM, Müller F, Lunden B, Berge RK, Frøland SS. Decreased levels of total and reduced glutathione in CD4+ lymphocytes in common variable immunodeficiency are associated with activation of the tumor necrosis factor system: possible immunopathogenic role of oxidative stress. Blood 1995; 86:1383-91. [PMID: 7632946] [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: 01/26/2023] Open
Abstract
We have previously shown chronic immune activation and enhanced generation of reactive oxygen species in common variable immunodeficiency (CVI). In the present study, we examined levels of glutathione, the dominant intracellular thiol, that play an important protective role against oxidative and inflammatory stress in plasma and in monocytes and lymphocyte subsets in 20 CVI patients and in 16 healthy controls. CD4+ lymphocytes from CVI patients had significantly lower levels of both total and reduced glutathione as well as a lower ratio of reduced to total glutathione compared with healthy controls. This decrease in glutathione levels in CD4+ lymphocytes was most pronounced in the CD45RA+ subset. Plasma levels of total glutathione were also significantly decreased in CVI. In contrast, monocytes from CVI patients exhibited increased levels of both total and reduced glutathione compared with blood donor monocytes. CVI patients had significantly raised serum levels of tumor necrosis factor alpha (TNF alpha) and TNF alpha concentration was strongly associated with glutathione depletion in CD4+ lymphocytes. Furthermore, the lowest levels of both total and reduced glutathione were found in a subgroup of CVI patients characterized by persistent immune activation in vivo, decreased numbers of CD4+ lymphocytes in peripheral blood, and splenomegaly. Finally, supplementation of cell cultures with glutathione-monoethyl ester did significantly enhance interleukin-2 production from peripheral blood mononuclear cells in CVI patients. These glutathione abnormalities in CVI indicate increased oxidative stress, particularly in CD4+ lymphocytes, and intracellular depletion of reduced glutathione of the demonstrated magnitude may have profound implications for CD4+ lymphocyte function and the immunodeficiency in CVI.
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Affiliation(s)
- P Aukrust
- Medical Department A, University of Oslo, National Hospital, Norway
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37
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Malik VB, Ahluwalia P. Studies on effect of monosodium glutamate (MSG) on various fractions of lipids and certain carbohydrate metabolic enzymes in liver and blood of adult male mice. Toxicol Lett 1994; 74:69-77. [PMID: 8085271 DOI: 10.1016/0378-4274(94)90075-2] [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: 01/28/2023]
Abstract
Monosodium glutamate (MSG) was administered subcutaneously to adult male mice for 6 days at dose levels of 2, 4, and 8 mg/g body wt. Dose levels above 4 mg/g body wt. showed significant increase in content of liver total lipids, phospholipids, triglycerides and free fatty acids, 31 days after the last injection. Blood glutamate level was significantly increased in all the groups but blood glutamine was increased in 4 and 8 mg/g body wt. groups (Groups III and IV) only. Blood pyruvate and glucose was significantly increased whereas liver glycogen and blood lactate was decreased in group III and IV. Activity of lactate dehydrogenase was significantly reduced both in serum and liver but the activity of glucose-6-phosphate dehydrogenase was significantly increased in RBC and liver at dose levels of 4 and 8 mg/g body wt. All these observations are suggestive of the fact that carbohydrate metabolism is shifted towards lipogenesis and hence leads to hyperlipidemia.
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Affiliation(s)
- V B Malik
- Department of Biochemistry, Punjab University, Chandigarh, India
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38
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Moukarzel AA, Goulet O, Salas JS, Marti-Henneberg C, Buchman AL, Cynober L, Rappaport R, Ricour C. Growth retardation in children receiving long-term total parenteral nutrition: effects of ornithine alpha-ketoglutarate. Am J Clin Nutr 1994; 60:408-13. [PMID: 8074074 DOI: 10.1093/ajcn/60.3.408] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [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: 01/28/2023] Open
Abstract
We evaluated the effect of ornithine ketoglutarate (OKG) in reversing abnormal growth in six prepubertal children receiving total parenteral nutrition (TPN) for 5-10 y. They were 1-4 SDs below their expected 50th percentile for height. The energy and nitrogen intakes were unchanged from 8 mo before the beginning of the study until its completion. Two consecutive periods of 5 mo each were studied. OKG (15 g) was added to the parenteral solution during the first period (OKG+) but not during the second period (OKG-). Height velocity (HV) increased (P < 0.05) from a median of 3.8 cm/y to 6.45 cm/y (range 1.8-6.7) during the OKG+ period, and decreased (P < 0.05) to a median of 3.65 cm/y in the OKG- period. Plasma concentrations of insulin-like growth factor 1 (IGF1), glutamine, and glutamate increased (P < 0.05) during the OKG+ period. Variations of IGF1 concentrations correlated with HV variations (r = 0.82, P < 0.005) during both periods. This study demonstrates that OKG is associated with statural growth acceleration and increased IGF1 concentrations.
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Affiliation(s)
- A A Moukarzel
- Department of Pediatrics, Maimonides Medical Center, Brooklyn, NY
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39
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Moores RR, Vaughn PR, Battaglia FC, Fennessey PV, Wilkening RB, Meschia G. Glutamate metabolism in fetus and placenta of late-gestation sheep. Am J Physiol 1994; 267:R89-96. [PMID: 7914073 DOI: 10.1152/ajpregu.1994.267.1.r89] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glutamate is produced by the fetal liver and taken up by the placenta. To explore the functional meaning of this exchange, the disposal rate (DR), clearance, conversion to glutamine, and decarboxylation rate of fetal plasma glutamate were studied at 129 +/- 2 days of gestation in seven fetal lambs infused via a systemic vein with L-[2,3,3,4,4-2H5]glutamate and L-[1-14C]glutamate. In two experiments, L-[1-13C]glutamate was also infused. The mean glutamate DR and clearance were 11.9 +/- 1.3 mumol.min-1.kg-1 and 200 +/- 8 ml.min-1.kg-1, respectively. The placenta extracted 88.5 +/- 0.8% of the tracer glutamate carried by the umbilical circulation and contributed to 61.3 +/- 3.2% of the glutamate DR. Most of the 14C infused as L-[1-14C]glutamate was converted to 14CO2: 37 +/- 4% by the fetus and 41 +/- 6% by the placenta. Of the labeled glutamate taken up by the placenta, 6.2 +/- 1.5% was returned to the fetus as glutamine. The glutamine-to-glutamate enrichment ratio in fetal arterial plasma was 0.066 +/- 0.008. We conclude that fetal plasma glutamate has an exceptionally high clearance because the flux of glutamate into the placenta is virtually equal to umbilical glutamate delivery rate. The main pathway of fetal plasma glutamate disposal is oxidation by placental and fetal tissues. Placental conversion of glutamate to fetal glutamine is a relatively small component of the placental metabolism of fetal glutamate.
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Affiliation(s)
- R R Moores
- Department of Pediatrics, University of Colorado School of Medicine, Denver 80262
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40
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Iwasaki Y, Ikeda K, Shiojima T, Kobayashi T, Kinoshita M. Different plasma glutamate levels in subtype of amyotrophic lateral sclerosis. Acta Neurol Scand 1994; 89:404-5. [PMID: 8085443 DOI: 10.1111/j.1600-0404.1994.tb02656.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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41
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Abstract
Evidence is presented that the high levels of internal L-glutamic and L-aspartic acid in frog (Rana esculenta) red blood cells are due to the existence of a specific carrier for acidic amino acids of high affinity (Km = 3 microM) and low capacity (Vmax 0.4 mumol L-Glu.Kg-1 dry cell mass.10 min-1). It is Na+ dependent and the incorporation of L-glutamic acid can be inhibited by L- and D-aspartate and L-cysteic acid, while D-glutamic does not inhibit. Moreover, this glutamic uptake shows a bell-shaped dependence on the external pH. All these properties show that this carrier belongs to the system X-AG family. Besides the incorporation through this system, L-glutamic acid is also taken up through the ASC system, although, under physiological conditions, this transport is far less important, since it has relatively low affinity (Km 39 microM) but high capacity (Vmax 1.8 mumol L-Glu.Kg-1 dry cell mass.10 min-1).
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Affiliation(s)
- M A Gallardo
- Dept. Bioquímica i Fisiologia, Universitat de Barcelona, Spain
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42
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Monaco F, Gianelli M, Schiavella MP, Naldi P, Cantello R, Torta R, Verzé L, Mutani R. Plasma amino acid alterations in idiopathic generalized epilepsy: an investigation in probands and their first-degree relatives. Ital J Neurol Sci 1994; 15:137-44. [PMID: 8056560 DOI: 10.1007/bf02339205] [Citation(s) in RCA: 2] [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: 01/28/2023]
Abstract
Twenty-two plasma amino acids were determined by means of ion-exchange chromatography in 16 previously untreated patients with generalized idiopathic epilepsy and in some of their first-degree relatives (26 subjects), and the results were compared with those obtained from a group of 50 healthy controls. The patients were subsequently treated with valproic acid for one month and then reexamined. In the epileptic subjects, statistical analysis showed significant alterations in the plasma levels of a group of amino acids, including the four associated with neuro-transmission (aspartate, glutamate, glycine, taurine); aspartate, glutamate and glycine levels were also altered in the first-degree relatives. Valproic acid therapy did not affect amino acid levels. If further confirmed, these alterations might be considered possible neurochemical markers of epilepsy.
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Affiliation(s)
- F Monaco
- Clinica Neurologica, Università di Sassari
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43
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Hamilton CL, Kirkwood JA. Column-switching high-performance liquid chromatographic method for the determination of a thymidylate synthase inhibitor, LY231514, an investigational agent for the treatment of solid tumors, in human plasma. J Chromatogr B Biomed Appl 1994; 654:297-303. [PMID: 8044293 DOI: 10.1016/0378-4347(93)e0447-x] [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] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A reversed-phase, column-switching high-performance liquid chromatographic (HPLC) method is described for the determination of a new thymidylate synthase inhibitor in human plasma. The compound and an internal standard are extracted from plasma using a Certify II solid-phase cartridge. Extracts are evaporated to dryness and the residue is reconstituted with mobile phase buffer. The analytes are separated from polar interferences and buffer salts originating from the elution step on a 4-mm YMC Basic pre-column. The fraction containing the analytes is further separated on a 25-cm YMC Basic column. The analytes are detected by their absorbance at 250 nm. The limit of quantitation is 10 ng/ml. The method is linear from 10 ng/ml to 80 micrograms/ml using three standard curve ranges. Validation studies for all three ranges show the method to be reproducible. The method has been successfully used to support pharmacokinetic studies.
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Affiliation(s)
- C L Hamilton
- Lilly Laboratory for Clinical Research, Indianapolis, IN 46202
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44
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Castillo J, Martínez F, Leira R, Prieto JM, Lema M, Noya M. [Changes in neuroexcitatory amino acids during and between migraine attacks]. Neurologia 1994; 9:42-5. [PMID: 8204247] [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: 01/29/2023] Open
Abstract
We studied changes in plasma levels of neuroexcitatory amino acids during and between migraine attacks in 16 patients with migraine without aura, 11 with aura and 21 controls. Glutamic acid levels between attacks were 1.027 +/- 0.60 and 0.890 +/- 0.41 mg/dl in migraine patients without and with aura, respectively; during attacks the levels were 0.535 +/- 0.23 and 0.601 +/- 0.20 for the same patients. The concentration of glutamic acid in the control group was 0.980 +/- 0.64 mg/dl. Aspartic acid levels between attacks in patients without and with aura were 0.179 +/- 0.04 and 0.167 +/- 0.03 mg/dl. Concentrations during attacks were 0.129 +/- 0.02 and 0.119 +/- 0.02 mg/dl for the same patients. Plasma levels of aspartic acid for controls were 0.146 +/- 0.03 mg/dl. We found no significant variations in neuroexcitatory amino acids between migraine attacks in patients with an without aura; changes took place only during attacks, possibly related to the mechanisms of the spreading depression process.
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Affiliation(s)
- J Castillo
- Servicio de Neurología, Hospital General de Galicia Clínico Universitario, Santiago de Compostela, La Coruña
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Blin O, Samuel D, Nieoullon A, Serratice G. Changes in CSF amino acid concentrations during the evolution of amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 1994; 57:119-20. [PMID: 8301293 PMCID: PMC485053 DOI: 10.1136/jnnp.57.1.119-a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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46
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Abstract
Growing rats were fed graded levels of threonine (Thr, 0.4, 0.8, and 3.3 g/100 g diet). Free amino acid content was measured in plasma and brain. Extracellular amino acid levels were measured by microdialysis in brain slices. Large quantities of dietary Thr (3.3 g/100 g) raised plasma and brain Thr and glycine (Gly) levels. Brain and spinal cord extracellular levels of Thr were also raised, whereas the other amino acid levels remained unchanged. A moderate level of dietary Thr (0.8 g/100 g) raised plasma Thr and Gly levels and brain Thr but not Gly level. The diet raised cortical Thr extracellular levels but did not modify the levels of the other amino acids, including glutamate (Glu) and aspartate (Asp). These data suggest that brain neurochemical processes involving Gly, Glu, and Asp are safeguarded in rats fed high Thr levels.
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Affiliation(s)
- V Castagné
- Nestec Ltd., Nestlé Research Centre, Vers-chez-les-Blanc, Lausanne, Switzerland
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47
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Affiliation(s)
- W Dröge
- Division of Immunochemistry, German Cancer Research Center, Heidelberg
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48
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Katz J, Wals P, Lee WN. Isotopomer studies of gluconeogenesis and the Krebs cycle with 13C-labeled lactate. J Biol Chem 1993; 268:25509-21. [PMID: 7902352] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Fasted rats were intragastrically infused with either [2,3-13C]lactate or [1,2,3-13C]lactate. The infusate also contained 14C-labeled lactate and [3-3H]glucose. Glucose, alanine, glutamate, and glutamine were isolated from liver and blood. There was near complete equilibration of lactate and alanine, and the relative specific activities and relative enrichments were the same in blood and liver. Glucose was cleaved enzymatically to lactate. The compounds were examined by gas chromatography-mass spectroscopy. From the mass isotopomer spectra of the lactate, glutamate, and glutamine and their cleavage fragments the positional isotopomer composition of these compounds was obtained. The enrichment and isotopomer pattern in the lactate from cleaved glucose represents that in phosphoenolpyruvate (PEP). When [1,2,3-13C]lactate was infused the mass isotopomer spectrum of glutamates consisted only of compounds containing either one, two, or three 13C carbons per molecule (m1, m2, and m3). There was little 13C in C-4 and C-5 of glutamate. The rate of pyruvate decarboxylation is low, and 3-4% of the acetyl-CoA flux in the Krebs cycle is contributed by lactate carbon. The major isotopomers in lactate, alanine, and PEP were m3 and m2 with 13C in C-2 and C-3. The predominant isotopomer in PEP from [2,3-13C]lactate was m2 with 13C in C-2 and C-3. There was much more of m1 isotopomer with 13C in C-3 and C-2 than the m1 isotopomer with 13C in C-1. There was very little m3, the isotopomer with 13C in all three carbons. Most of the 13C in C-3 and C-4 of glucose and C-1 of glutamate was introduced via 13CO2 fixation. From the isotopomer distribution and the rate of glucose turnover we deduced, applying the analysis described in the "Appendix," the absolute rates of gluconeogenic pathways, recycling of PEP and the Cori cycle, and flux in the Krebs cycle. The flux from oxaloacetate (OAA)-->PEP was seven times that of OAA-->citrate, and about half of PEP was recycled to pyruvate via pyruvate kinase. The mass isotopomer patterns in glutamate and glutamine were similar but differed from those of lactate and glucose. It appears that the glutamates are derived from alpha-ketoglutarate from a different Krebs cycle pool than PEP. The flux from OAA to PEP in this pool was two to three times that of OAA to citrate.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J Katz
- Cedars-Sinai Medical Center, Los Angeles, California 90048
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49
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Abstract
Plasma and platelet levels of excitatory amino acids were measured in 38 psychiatric out-patients and in 19 comparison subjects; the patients had DSM-III-R diagnoses of organic mental disorders (N = 3), mood disorders (N = 15), schizophrenia (N = 13), and anxiety disorders (N = 7). The glutamate plasma levels were significantly higher in the patients with mood disorders than in the comparison group.
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Affiliation(s)
- C A Altamura
- Department of Clinical Psychiatry, University of Milan School of Medicine, Italy
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50
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Krauss SW, Ghirnikar RB, Diamond I, Gordon AS. Inhibition of adenosine uptake by ethanol is specific for one class of nucleoside transporters. Mol Pharmacol 1993; 44:1021-6. [PMID: 7902530] [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: 01/27/2023] Open
Abstract
Adenosine uptake via nucleoside transporters is inhibited when S49 and NG108-15 cell lines cells are exposed to ethanol. This inhibition leads to an accumulation of extracellular adenosine that binds to adenosine A2 receptors and increases cAMP production. Subsequently, there is a heterologous desensitization of receptors coupled to adenylyl cyclase for which adenosine also is required. There are multiple classes of facilitative and concentrative nucleoside transporters that could be inhibited by ethanol to initiate this cascade of events. In this paper, we establish that adenosine uptake by only one type of nucleoside transporter, an NBMPR-sensitive facilitative transporter, is inhibited by ethanol. There is no effect on other classes of nucleoside transporters even when present in the same cell. Thus, ethanol-induced extracellular accumulation of adenosine results specifically from inhibition of NBMPR-sensitive facilitative nucleoside transporters. We also find that human lymphocytes express only facilitative nucleoside transporters and that the NBMPR-sensitive type is predominant. Thus, inhibition of this type of transporter by ethanol may be related to the desensitization of cAMP signal transduction that we have reported in lymphocytes from alcoholics.
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Affiliation(s)
- S W Krauss
- Ernest Gallo Clinic, University of California, San Francisco 94143
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