Pub Date : 2013-07-26DOI: 10.2174/1874360920130702001
L. Belkacemi, G. Selselet-Attou, M. Antoine, J. Nortier, E. Hupkens, A. Sener, W. Malaisse
Intermittent fasting was previously reported to exert beneficial effects in sand rats, an animal model of diabetes. The present report complements recent comparable findings recorded in streptozotocin-induced diabetic rats (STZ rats). Intermittent fasting minimized the increase in pancreatic, hepatic and renal weight otherwise observed in the STZ rats. The glycogen content of the liver was higher in the STZ rats than in the control animals. It was positively correlated, at the individual level, with the hepatic glucose content. Significant positive correlations also prevailed between the plasma glucose concentration at sacrifice, which was lower in intermittently fasting or calorie-restricted STZ rats than in non- fasting STZ rats, and either the liver glucose content or liver total carbohydrate content. The kidney PCNA (proliferating cell nuclear antigen) index, as well as the plasma creatinine and urea concentrations, were also lower in intermittently fast- ing or calorie-restricted STZ rats than in non-fasting diabetic animals. These findings reinforce the view that intermittent fasting may exert a favourable effect, in terms of glucose homeostasis and the undesirable consequences of its perturba- tion, in diabetic animals.
{"title":"Intermittent Fasting Modulation of the Diabetic Syndrome in Streptozotocin- Injected Rats: Post-Mortem Investigations","authors":"L. Belkacemi, G. Selselet-Attou, M. Antoine, J. Nortier, E. Hupkens, A. Sener, W. Malaisse","doi":"10.2174/1874360920130702001","DOIUrl":"https://doi.org/10.2174/1874360920130702001","url":null,"abstract":"Intermittent fasting was previously reported to exert beneficial effects in sand rats, an animal model of diabetes. The present report complements recent comparable findings recorded in streptozotocin-induced diabetic rats (STZ rats). Intermittent fasting minimized the increase in pancreatic, hepatic and renal weight otherwise observed in the STZ rats. The glycogen content of the liver was higher in the STZ rats than in the control animals. It was positively correlated, at the individual level, with the hepatic glucose content. Significant positive correlations also prevailed between the plasma glucose concentration at sacrifice, which was lower in intermittently fasting or calorie-restricted STZ rats than in non- fasting STZ rats, and either the liver glucose content or liver total carbohydrate content. The kidney PCNA (proliferating cell nuclear antigen) index, as well as the plasma creatinine and urea concentrations, were also lower in intermittently fast- ing or calorie-restricted STZ rats than in non-fasting diabetic animals. These findings reinforce the view that intermittent fasting may exert a favourable effect, in terms of glucose homeostasis and the undesirable consequences of its perturba- tion, in diabetic animals.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126072290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-02-01DOI: 10.2174/1874360901104010001
W. Malaisse, M. Hacquebard, Ying Zhang, Nurdan Bulur, A. Sener, Y. Carpentier
The present report complements recent publications on the occurrence of a metabolic syndrome in rats deprived of a dietary supply of long-chain polyunsaturated � 3 fatty acids and on the attempt to correct the resulting metabolic and hormonal defects by exposure of the � 3-depleted rats to a diet enriched with flaxseed oil rich in � -linolenic acid (C18:3� 3). Emphasis is placed (i) on the much slower time course for the depletion in docosahexaenoic acid (C22:6� 3) and accumulation of docosapentaenoic acid (C22:5� 6) and their reversal during dietary deprivation and replenishment of � 3 fatty acids in brain phospholipids, as opposed to liver or intestinal phospholipids, (ii) on the role of circulating phos- pholipids in the transfer of C22:6� 3, synthesized from C18:3� 3 in hepatocytes, from the liver to the brain in the rats de- prived of a dietary supply of � 3 fatty acids, and (iii) on the unfavorable effect of an increase in the total lipid content of the diet from 5 to 10% (w/w) in the perspective of the correction of liver steatosis and visceral obesity in the � 3-depleted rats.
{"title":"The Metabolic Syndrome of ω3-Depleted Rats. X: Comprehensive View","authors":"W. Malaisse, M. Hacquebard, Ying Zhang, Nurdan Bulur, A. Sener, Y. Carpentier","doi":"10.2174/1874360901104010001","DOIUrl":"https://doi.org/10.2174/1874360901104010001","url":null,"abstract":"The present report complements recent publications on the occurrence of a metabolic syndrome in rats deprived of a dietary supply of long-chain polyunsaturated � 3 fatty acids and on the attempt to correct the resulting metabolic and hormonal defects by exposure of the � 3-depleted rats to a diet enriched with flaxseed oil rich in � -linolenic acid (C18:3� 3). Emphasis is placed (i) on the much slower time course for the depletion in docosahexaenoic acid (C22:6� 3) and accumulation of docosapentaenoic acid (C22:5� 6) and their reversal during dietary deprivation and replenishment of � 3 fatty acids in brain phospholipids, as opposed to liver or intestinal phospholipids, (ii) on the role of circulating phos- pholipids in the transfer of C22:6� 3, synthesized from C18:3� 3 in hepatocytes, from the liver to the brain in the rats de- prived of a dietary supply of � 3 fatty acids, and (iii) on the unfavorable effect of an increase in the total lipid content of the diet from 5 to 10% (w/w) in the perspective of the correction of liver steatosis and visceral obesity in the � 3-depleted rats.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115793619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-08DOI: 10.2174/1874360901003010037
Mohati Desai-Shah, R. Cooper
Residual Ca 2+ can accumulate in the nerve terminal during repetitive stimulation; thus, the basis for short-term facilitation (STF). The plasmalemmal Na + /Ca 2+ exchanger (NCX), the Ca 2+ -ATPase (PMCA) and the sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase (SERCA) on the endoplasmic reticulum are three important Ca 2+ regulatory processes in controlling (Ca 2+ )i. The role of these (Ca 2+ )i regulators in the development and maintenance of STF was addressed at the neuromuscular junction. When the NCX is compromised by reduced (Na + )o, the EPSP amplitudes decrease, but with KB-R7943 (a reverse blocker of NCX) the amplitude increases. Compromising the PMCA with pH 8.8 produces an increase in EPSP amplitudes, but treatments with carboxyeosin (a blocker of PMCA) produced mixed results. Blocking the SERCA increases EPSP amplitudes. Facilitation was only slighted altered in some conditions with these manipulations. The results support the view that release is not saturated during a plateau phase of STF since the terminal is able to reach a new plateau with higher stimulation frequency or an altered (Ca 2+ )i. Multiple approaches in compromising the NCX and PMCA are presented. These findings are significant because there is a rapid alteration in transmission when compromising Ca 2+ extrusion mechanisms during STF.
{"title":"Actions of NCX, PMCA and SERCA on Short-Term Facilitation and Maintenance of Transmission in Nerve Terminals","authors":"Mohati Desai-Shah, R. Cooper","doi":"10.2174/1874360901003010037","DOIUrl":"https://doi.org/10.2174/1874360901003010037","url":null,"abstract":"Residual Ca 2+ can accumulate in the nerve terminal during repetitive stimulation; thus, the basis for short-term facilitation (STF). The plasmalemmal Na + /Ca 2+ exchanger (NCX), the Ca 2+ -ATPase (PMCA) and the sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase (SERCA) on the endoplasmic reticulum are three important Ca 2+ regulatory processes in controlling (Ca 2+ )i. The role of these (Ca 2+ )i regulators in the development and maintenance of STF was addressed at the neuromuscular junction. When the NCX is compromised by reduced (Na + )o, the EPSP amplitudes decrease, but with KB-R7943 (a reverse blocker of NCX) the amplitude increases. Compromising the PMCA with pH 8.8 produces an increase in EPSP amplitudes, but treatments with carboxyeosin (a blocker of PMCA) produced mixed results. Blocking the SERCA increases EPSP amplitudes. Facilitation was only slighted altered in some conditions with these manipulations. The results support the view that release is not saturated during a plateau phase of STF since the terminal is able to reach a new plateau with higher stimulation frequency or an altered (Ca 2+ )i. Multiple approaches in compromising the NCX and PMCA are presented. These findings are significant because there is a rapid alteration in transmission when compromising Ca 2+ extrusion mechanisms during STF.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132891580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-03DOI: 10.2174/1874360901003010016
Mohati Desai-Shah, A. Papoy, M. Ward, R. Cooper
We investigated the roles of three regulatory proteins that impact [Ca 2+ ]i within cardiac myocytes of Drosophila melanogaster. The NCX (Na + /Ca 2+ exchanger), PMCA (plasma membrane Ca 2+ -ATPase) and SERCA (sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase) were compromised by ionic, pharmacological, mutationalmanipulation, and with a combination of approaches, while heart rate (HR) was monitored. A decrease in SERCA function reduced HR more for intact larva in comparison to a dissected larva. Dissected preparations were used to expose the heart directly to agents. A compromised PMCA also reduced HR; however, attenuated NCX function by low [Na + ]o increased HR. KBR7943, a blocker of Ca 2+ entry via NCX, exposure increased HR. A combined loss of function in all three channels did not show a significant change in HR. The results indicate that NCX and PMCA are important in regulating HR, whereas SERCA does not have as pronounced role for dissected preparations. However, with intact preparations the loss of SERCA function by a mutation does have a significant impact on HR. Pharmacological approaches to alter PMCA and SERCA paralleled the results obtained by ionic and mutational approaches. To further understand the pacemaker activity, intracellular recordings were obtained. Mapping of action-potentials in myocytes revealed that the caudal region of the heart has large amplitude potentials and is likely to contain the pacemaker cells. The Drosophila heart can serve as a genetic model in understanding regulation of ionic currents for pacing cells of various types.
{"title":"Roles of the Sarcoplasmic/Endoplasmic Reticulum Ca2+-ATPase, Plasma Membrane Ca2+-ATPase and Na+/Ca2+ Exchanger in Regulation of Heart Rate in Larval Drosophila","authors":"Mohati Desai-Shah, A. Papoy, M. Ward, R. Cooper","doi":"10.2174/1874360901003010016","DOIUrl":"https://doi.org/10.2174/1874360901003010016","url":null,"abstract":"We investigated the roles of three regulatory proteins that impact [Ca 2+ ]i within cardiac myocytes of Drosophila melanogaster. The NCX (Na + /Ca 2+ exchanger), PMCA (plasma membrane Ca 2+ -ATPase) and SERCA (sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase) were compromised by ionic, pharmacological, mutationalmanipulation, and with a combination of approaches, while heart rate (HR) was monitored. A decrease in SERCA function reduced HR more for intact larva in comparison to a dissected larva. Dissected preparations were used to expose the heart directly to agents. A compromised PMCA also reduced HR; however, attenuated NCX function by low [Na + ]o increased HR. KBR7943, a blocker of Ca 2+ entry via NCX, exposure increased HR. A combined loss of function in all three channels did not show a significant change in HR. The results indicate that NCX and PMCA are important in regulating HR, whereas SERCA does not have as pronounced role for dissected preparations. However, with intact preparations the loss of SERCA function by a mutation does have a significant impact on HR. Pharmacological approaches to alter PMCA and SERCA paralleled the results obtained by ionic and mutational approaches. To further understand the pacemaker activity, intracellular recordings were obtained. Mapping of action-potentials in myocytes revealed that the caudal region of the heart has large amplitude potentials and is likely to contain the pacemaker cells. The Drosophila heart can serve as a genetic model in understanding regulation of ionic currents for pacing cells of various types.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133794280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-07-06DOI: 10.2174/1874360901003010001
W. Malaisse, Ying Zhang, Nurdan Bulur, M. Hacquebard, Y. Larondelle, Y. Carpentier, A. Sener
The present study aims at investigating the determinants of the undesirable aggravation of liver steatosis observed in rats first deprived, for 7 months from the 6 th week after birth onwards, of a dietary supply of long-chain polyunsaturated 3 fatty acids by exposure to a 5% sunflower oil-containing diet and then given access for about 2 weeks to the same diet enriched with 5% flaxseed oil in order to restore a sufficient 3 fatty acid content of tissue lipids. Control rats were exposed for 7 months to a 5% soybean oil-containing diet and then given access for about 2 weeks to the same diet enriched with either 5% flaxseed oil or another 5% soybean oil. In all cases, the increase in the lipid content of the diet provoked an increase in liver triglyceride content. The ratio between the daily increment in the C18:3 3 content of liver triglycerides caused by the switch in diet and the C18:3 3 relative content of the diet used after the switch averaged 0.035 in the control rats eventually exposed to the soybean-enriched diet, 0.051 in the control rats eventually exposed to the flaxseed oil-enriched diet and 0.120 in the 3-deficient rats eventually also exposed to a flaxseed oil-enriched diet. Thus, under the present experimental conditions, the induction or aggravation of liver steatosis, and possibly also the parallel increase in adipose tissue mass, may correspond to the deposition of dietary lipids, also involving an increase in food intake, more pronounced in the 3-depleted rats than in the control animals.
{"title":"The Metabolic Syndrome of ω3-Depleted Rats. VIII. Dietary Lipid- Induced Liver Steatosis~!2009-08-18~!2009-11-13~!2010-06-11~!","authors":"W. Malaisse, Ying Zhang, Nurdan Bulur, M. Hacquebard, Y. Larondelle, Y. Carpentier, A. Sener","doi":"10.2174/1874360901003010001","DOIUrl":"https://doi.org/10.2174/1874360901003010001","url":null,"abstract":"The present study aims at investigating the determinants of the undesirable aggravation of liver steatosis observed in rats first deprived, for 7 months from the 6 th week after birth onwards, of a dietary supply of long-chain polyunsaturated 3 fatty acids by exposure to a 5% sunflower oil-containing diet and then given access for about 2 weeks to the same diet enriched with 5% flaxseed oil in order to restore a sufficient 3 fatty acid content of tissue lipids. Control rats were exposed for 7 months to a 5% soybean oil-containing diet and then given access for about 2 weeks to the same diet enriched with either 5% flaxseed oil or another 5% soybean oil. In all cases, the increase in the lipid content of the diet provoked an increase in liver triglyceride content. The ratio between the daily increment in the C18:3 3 content of liver triglycerides caused by the switch in diet and the C18:3 3 relative content of the diet used after the switch averaged 0.035 in the control rats eventually exposed to the soybean-enriched diet, 0.051 in the control rats eventually exposed to the flaxseed oil-enriched diet and 0.120 in the 3-deficient rats eventually also exposed to a flaxseed oil-enriched diet. Thus, under the present experimental conditions, the induction or aggravation of liver steatosis, and possibly also the parallel increase in adipose tissue mass, may correspond to the deposition of dietary lipids, also involving an increase in food intake, more pronounced in the 3-depleted rats than in the control animals.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115632179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-01-04DOI: 10.2174/1874360900902010018
N. Schneider, A. Amano
Since regulation of cardiac muscle contraction is complex, many simulation studies have been conducted to systematically analyze regulatory mechanisms underlying the force-velocity relationship. However, past studies were performed with models lacking detailed thin filament activation despite its essential regulatory role. Here a novel cardiac muscle contraction model is presented that considers troponin C, troponin I and tropomyosin for thin filament activation coupled with the cross-bridge (Xb) cycle, and in addition, includes a potential Frank-Starling mechanism and simple Xb mechanics. This model was employed to elucidate load and sarcomere length-dependence of the thin filament and Xb kinetics during muscle shortening and relaxation. Simulation analysis of afterloaded isotonic contractions performed at various preloads revealed that at medium to high load the peak Xb concentration, regulated by a load-dependent change of the ADP release rate, is the major factor in determining the end-systolic half sarcomere length, whereas the velocitydependent Xb force only shows a small influence. At low load, shortening velocity is regulated through an increase in the rate of the tropomyosin conformational change as for all preloads the same Xb concentration is attained. Shorteninginduced cooperative deactivation was caused by the included Frank-Starling mechanism. An analysis of newly suggested relaxation mechanisms showed the significance for an increased thin filament deactivation with troponin I pulling tropomyosin to the “off” position having a greater impact than titin restoring force assumed to disrupt the tropomyosin structure. A combination of this model with the myocyte Kyoto Model satisfactorily reproduced isotonic contraction time courses from guinea pig myocytes.
{"title":"Simulation Analysis of Cardiac Muscle Isotonic Contractions at Different Pre- and Afterloads","authors":"N. Schneider, A. Amano","doi":"10.2174/1874360900902010018","DOIUrl":"https://doi.org/10.2174/1874360900902010018","url":null,"abstract":"Since regulation of cardiac muscle contraction is complex, many simulation studies have been conducted to systematically analyze regulatory mechanisms underlying the force-velocity relationship. However, past studies were performed with models lacking detailed thin filament activation despite its essential regulatory role. Here a novel cardiac muscle contraction model is presented that considers troponin C, troponin I and tropomyosin for thin filament activation coupled with the cross-bridge (Xb) cycle, and in addition, includes a potential Frank-Starling mechanism and simple Xb mechanics. This model was employed to elucidate load and sarcomere length-dependence of the thin filament and Xb kinetics during muscle shortening and relaxation. Simulation analysis of afterloaded isotonic contractions performed at various preloads revealed that at medium to high load the peak Xb concentration, regulated by a load-dependent change of the ADP release rate, is the major factor in determining the end-systolic half sarcomere length, whereas the velocitydependent Xb force only shows a small influence. At low load, shortening velocity is regulated through an increase in the rate of the tropomyosin conformational change as for all preloads the same Xb concentration is attained. Shorteninginduced cooperative deactivation was caused by the included Frank-Starling mechanism. An analysis of newly suggested relaxation mechanisms showed the significance for an increased thin filament deactivation with troponin I pulling tropomyosin to the “off” position having a greater impact than titin restoring force assumed to disrupt the tropomyosin structure. A combination of this model with the myocyte Kyoto Model satisfactorily reproduced isotonic contraction time courses from guinea pig myocytes.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121869480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-14DOI: 10.2174/1874360900902010014
M. Mohammad, K. Talafih, M. J. Mohamad, Pao-Yuan El-Akawi
Objectives: In this study the effects of different Leptin concentrations on the blood pressure and heart rate in vivo in anesthetized rabbits were studied. Methods: Sixty Rabbits were divided into two groups, first group received Leptin intra-venously and other group received Leptin intra-arterially. Blood pressure and heart rate in were recorded before and after administration of Leptin. Results: A significant increase in mean arterial blood pressure (MABP) was seen after an intra-arterial injection of 3, 5 and 7 � g/kg of Leptin. This increase in MABP was monitored for different durations 10, 20 and 30 minutes after the infu- sion of each Leptin concentrations. The trend of the increase in MABP with time was demonstrated with all three concen- trations. Intra-venous infusion of Leptin caused a significant decrease in MABP after 10 minutes as well as after 20 and 30 minutes, with all three concentrations (3, 5, and 7 μg/Kg). Heart rate (HR) was not changed significantly at the end of 30 min of infusion. Conclusion: this in vivo study demonstrated that intra-venous Leptin infusion has a different effect on the MABP com- pared with intra-arterial infusion and this difference might be due to the site of action of Leptin.
{"title":"Effect of Intra-Venous Versus Intra-Arterial Leptin Infusion on Blood Pressure and Heart Rate","authors":"M. Mohammad, K. Talafih, M. J. Mohamad, Pao-Yuan El-Akawi","doi":"10.2174/1874360900902010014","DOIUrl":"https://doi.org/10.2174/1874360900902010014","url":null,"abstract":"Objectives: In this study the effects of different Leptin concentrations on the blood pressure and heart rate in vivo in anesthetized rabbits were studied. Methods: Sixty Rabbits were divided into two groups, first group received Leptin intra-venously and other group received Leptin intra-arterially. Blood pressure and heart rate in were recorded before and after administration of Leptin. Results: A significant increase in mean arterial blood pressure (MABP) was seen after an intra-arterial injection of 3, 5 and 7 � g/kg of Leptin. This increase in MABP was monitored for different durations 10, 20 and 30 minutes after the infu- sion of each Leptin concentrations. The trend of the increase in MABP with time was demonstrated with all three concen- trations. Intra-venous infusion of Leptin caused a significant decrease in MABP after 10 minutes as well as after 20 and 30 minutes, with all three concentrations (3, 5, and 7 μg/Kg). Heart rate (HR) was not changed significantly at the end of 30 min of infusion. Conclusion: this in vivo study demonstrated that intra-venous Leptin infusion has a different effect on the MABP com- pared with intra-arterial infusion and this difference might be due to the site of action of Leptin.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121037349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-04-20DOI: 10.2174/1874360900902010006
Y. Kao, S. Hsi, Yuan-Ping Kao, Pao-Yuan Wang, Hong-Ming Chao, Chung-Hsiung Huang, Hang‐Seng Liu, L. Shih, J. Tschen, Ching-Ling Lin
Grape seed procyanidins (GSPCs) are bioflavonoid polymers that have been shown to have health benefits. We assessed the antidiabetic effect of GSPC in mice. Mice with streptozotocin(STZ)-induced diabetes were orally or intrape- ritoneally administered saline or 40-100 mg GSPC/kg BW daily for 7-10 d. We monitored body weight, blood glucose levels, amounts of food and water consumed, and amounts of urine and feces excreted. On the final day, we analyzed plasma chemistry and found that GSPC, but not structurally related monomers (e.g., catechin and epicatechin), reduced the glucose levels, food and water intake, and urine and feces excreted, all of which had increased due to STZ administra- tion. This suggests a procyanidin-dependent effect of grape seed polyphenols on diabetes. Oral administration of GSPC was less effective within 9 d than was intraperitoneal administration of GSPC, suggesting that the effect is route- dependent. The decrease in diabetic blood glucose levels was reversible; when GSPC administration was stopped, glucose levels rose. However, although pretreatment with GSPC for 7 d did not completely prevent STZ-induced diabetic effects, it rapidly reduced them. Treatment with GSPC reduced fasting glucose levels and improved glucose tolerance in STZ- treated mice, in addition to decreasing STZ-stimulated levels of plasma triglyceride and cholesterol, creatinine, uric acid, and alkaline phosphatase activity. Moreover, GSPC suppressed the reduction in pancreatic islets and the decrease in plasma insulin hormone levels caused by STZ. Our findings indicate that GSPC improves hyperglycemia, polydipsia, polyuria, and polyphagia in mice with STZ-induced diabetes.
{"title":"Grape Seed Procyanidins Improve Diabetic Symptoms in Mice with Streptozotocin-Induced Diabetes","authors":"Y. Kao, S. Hsi, Yuan-Ping Kao, Pao-Yuan Wang, Hong-Ming Chao, Chung-Hsiung Huang, Hang‐Seng Liu, L. Shih, J. Tschen, Ching-Ling Lin","doi":"10.2174/1874360900902010006","DOIUrl":"https://doi.org/10.2174/1874360900902010006","url":null,"abstract":"Grape seed procyanidins (GSPCs) are bioflavonoid polymers that have been shown to have health benefits. We assessed the antidiabetic effect of GSPC in mice. Mice with streptozotocin(STZ)-induced diabetes were orally or intrape- ritoneally administered saline or 40-100 mg GSPC/kg BW daily for 7-10 d. We monitored body weight, blood glucose levels, amounts of food and water consumed, and amounts of urine and feces excreted. On the final day, we analyzed plasma chemistry and found that GSPC, but not structurally related monomers (e.g., catechin and epicatechin), reduced the glucose levels, food and water intake, and urine and feces excreted, all of which had increased due to STZ administra- tion. This suggests a procyanidin-dependent effect of grape seed polyphenols on diabetes. Oral administration of GSPC was less effective within 9 d than was intraperitoneal administration of GSPC, suggesting that the effect is route- dependent. The decrease in diabetic blood glucose levels was reversible; when GSPC administration was stopped, glucose levels rose. However, although pretreatment with GSPC for 7 d did not completely prevent STZ-induced diabetic effects, it rapidly reduced them. Treatment with GSPC reduced fasting glucose levels and improved glucose tolerance in STZ- treated mice, in addition to decreasing STZ-stimulated levels of plasma triglyceride and cholesterol, creatinine, uric acid, and alkaline phosphatase activity. Moreover, GSPC suppressed the reduction in pancreatic islets and the decrease in plasma insulin hormone levels caused by STZ. Our findings indicate that GSPC improves hyperglycemia, polydipsia, polyuria, and polyphagia in mice with STZ-induced diabetes.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122124474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-04-10DOI: 10.2174/1874360900902010001
Wen-Xiu Li, Min Zong, Min Fu, Y. Zhai, Zuo‐ping Xie, Ru-Lin Liu
Ginsenoside Rg1, the main active ingredient of Ginseng Radix which is a famous Chinese medicine, is widely used as an anti-stress, anti-aging and neurological performance improving agent. In this study, we used calcium imaging and whole-cell patch clamp techniques to investigate the effect of Ginsenoside Rg1 on spontaneous and synchronous Ca 2+ oscillations and the possible mechanisms in primarily cultured hippocampal neuronal networks. We found that Ginse- noside Rg1 could decrease the frequencies of spontaneous and synchronous Ca 2+ oscillations and inhibit the amplitude of high-voltage activated calcium channel currents. These results provided the experimental evidence for the clinical applica- tion of Rg1 as a neuroprotector on the cellular level, and enriched the theoretical system of Chinese medicine.
{"title":"Ginsenoside Rg1 Modulates Spontaneous Synchronous Ca2+ Oscillations of Cultured Hippocampal Neurons","authors":"Wen-Xiu Li, Min Zong, Min Fu, Y. Zhai, Zuo‐ping Xie, Ru-Lin Liu","doi":"10.2174/1874360900902010001","DOIUrl":"https://doi.org/10.2174/1874360900902010001","url":null,"abstract":"Ginsenoside Rg1, the main active ingredient of Ginseng Radix which is a famous Chinese medicine, is widely used as an anti-stress, anti-aging and neurological performance improving agent. In this study, we used calcium imaging and whole-cell patch clamp techniques to investigate the effect of Ginsenoside Rg1 on spontaneous and synchronous Ca 2+ oscillations and the possible mechanisms in primarily cultured hippocampal neuronal networks. We found that Ginse- noside Rg1 could decrease the frequencies of spontaneous and synchronous Ca 2+ oscillations and inhibit the amplitude of high-voltage activated calcium channel currents. These results provided the experimental evidence for the clinical applica- tion of Rg1 as a neuroprotector on the cellular level, and enriched the theoretical system of Chinese medicine.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116003944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.2174/1874360900801010034
G. Hoffmann, V. Leichtfried, A. Griesmacher, C. Bartenbach, M. Canazei, S. Staggl, W. Schobersberger
Shift work is associated with alterations in physiological circadian patterns resulting in chronic diseases, e.g. cardiovascular disorders or major depression. The intensity and spectral composition of light is known to affect the 24 h- rhythm of our body. We investigated the effects of two different lighting environments on parameters of circadian rhythm and performance in healthy volunteers during an experimental night shift. Test light with a low color temperature was compared to normal light with a higher color temperature. Melatonin synthesis, red and white blood count, blood pressure, heart rate and indicators of performance were analyzed. Nocturnal increases in melatonin were more pronounced under low color temperature lighting conditions. This was not associated with limited degrees of arousal or vigilance. Mainte- nance of a normal nocturnal rhythm of melatonin with adapted illumination may provide a benefit for employees well- being without affecting their productivity.
{"title":"Effects of Light With Reduced Short Wavelength Components on Parameters of Circadian Rhythm and Performance in an Experimental Night Shift Model","authors":"G. Hoffmann, V. Leichtfried, A. Griesmacher, C. Bartenbach, M. Canazei, S. Staggl, W. Schobersberger","doi":"10.2174/1874360900801010034","DOIUrl":"https://doi.org/10.2174/1874360900801010034","url":null,"abstract":"Shift work is associated with alterations in physiological circadian patterns resulting in chronic diseases, e.g. cardiovascular disorders or major depression. The intensity and spectral composition of light is known to affect the 24 h- rhythm of our body. We investigated the effects of two different lighting environments on parameters of circadian rhythm and performance in healthy volunteers during an experimental night shift. Test light with a low color temperature was compared to normal light with a higher color temperature. Melatonin synthesis, red and white blood count, blood pressure, heart rate and indicators of performance were analyzed. Nocturnal increases in melatonin were more pronounced under low color temperature lighting conditions. This was not associated with limited degrees of arousal or vigilance. Mainte- nance of a normal nocturnal rhythm of melatonin with adapted illumination may provide a benefit for employees well- being without affecting their productivity.","PeriodicalId":331207,"journal":{"name":"The Open Physiology Journal","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128268556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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