目的评价阻塞性睡眠呼吸暂停综合征(OSAS)正常糖耐量(NGT)患者持续正压通气(CPAP)治疗前后胰岛β细胞功能和胰岛素抵抗情况。方法对35例OSAS正常糖耐量(NGT)患者CPAP治疗前后,全部行口服葡萄糖耐量试验,计算治疗前后早时相胰岛素生成指...目的评价阻塞性睡眠呼吸暂停综合征(OSAS)正常糖耐量(NGT)患者持续正压通气(CPAP)治疗前后胰岛β细胞功能和胰岛素抵抗情况。方法对35例OSAS正常糖耐量(NGT)患者CPAP治疗前后,全部行口服葡萄糖耐量试验,计算治疗前后早时相胰岛素生成指数和胰岛素抵抗指数。结果 OSAS NGT患者CPAP治疗后患者早时相胰岛素生成指数上升(P<0.05),胰岛素抵抗指数下降(P<0.05)。结论 OSAS患者经过CPAP治疗后能改善胰岛素分泌,减轻胰岛素抵抗。展开更多
Glucose homeostasis deficiency leads to a chronic increase in blood glucose concentration. In contrast to physiological glucose concentration, chronic super-physiological glucose concentration negatively affects a lar...Glucose homeostasis deficiency leads to a chronic increase in blood glucose concentration. In contrast to physiological glucose concentration, chronic super-physiological glucose concentration negatively affects a large number of organs and tissues. Glucose toxicity means a decrease in insulin secretion and an increase in insulin resistance due to chronic hyperglycemia. It is now generally accepted that glucose toxicity is involved in the worsening of diabetes by affecting the secretion of B-cells. Several mechanisms have been proposed to explain the adverse effects of hyperglycemia. It was found that persistent hyperglycemia caused the functional decline of neutrophils. Infection is thus the main problem resulting from glucose toxicity in the acute phase. In other words, continued hyperglycemia is a life-threatening risk factor, not only in the chronic but also the acute phase, and it becomes a risk factor for infection, particularly in the perioperative period.展开更多
Ghrelin,a 28 amino acid peptide hormone produced by the stomach,was the first orexigenic hormone to be discovered from the periphery.The octanoyl modification at Ser3,mediated by ghrelin O-acyltransferase(GOAT),is ess...Ghrelin,a 28 amino acid peptide hormone produced by the stomach,was the first orexigenic hormone to be discovered from the periphery.The octanoyl modification at Ser3,mediated by ghrelin O-acyltransferase(GOAT),is essential for ghrelin's biological activity.Ghrelin stimulates food intake through binding to its receptor(GRLN-R) on neurons in the arcuate nucleus of the hypothalamus.Ghrelin is widely expressed throughout the body;accordingly,it is implicated in several other physiological functions,which include growth hormone release,gastric emptying,and body weight regulation.Ghrelin and GRLN-R expression are also found in the pancreas,suggesting a local physiological role.Accordingly,several recent studies now point towards an important role for ghrelin and its receptor in the regulation of blood glucose homeostasis,which is the main focus of this review.Several mechanisms of this regulation by ghrelin have been proposed,and one possibility is through the regulation of insulin secretion.Despite some controversy,most studies suggest that ghrelin exerts an inhibitory effect on insulin secretion,resulting in increased circulating glucose levels.Ghrelin may thus be a diabetogenic factor.Obesity-related type2 diabetes has become an increasingly important health problem,almost reaching epidemic proportions in the world;therefore,antagonists of the ghrelin-GOAT signaling pathway,which will tackle both energy-and glucose homeostasis,may be considered as promising new therapies for this disease.展开更多
INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secret...INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence （TIRF） microscopy has been employed to study insulin secretion.展开更多
Nigella sativa decreases DNA damage and thereby prevents initiation of carcinogenesis in colonic tissue secondary to exposure to toxic agents such as azoxymethane. N. sativa is of immense therapeutic benefit in diabet...Nigella sativa decreases DNA damage and thereby prevents initiation of carcinogenesis in colonic tissue secondary to exposure to toxic agents such as azoxymethane. N. sativa is of immense therapeutic benefit in diabetic individuals and those with glucose intolerance as it accentuates glucose-induced secretion of insulin besides having a negative impact on glucose absorption from the intestinal mucosa. N. sativa administration protects hepatic tissue from deleterious effects of toxic metals such as lead, and attenuates hepatic lipid peroxidation following exposure to chemicals such as carbon tetrachloride.展开更多
Objective To elucidate GPR40/FFA1 and its downstream signaling pathways in regulating insulin secretion. Methods GPR40/FFA1 expression was detected by immunofluorescence imaging. We employed linoleic acid (LA), a free...Objective To elucidate GPR40/FFA1 and its downstream signaling pathways in regulating insulin secretion. Methods GPR40/FFA1 expression was detected by immunofluorescence imaging. We employed linoleic acid (LA), a free fatty acid that has a high affinity to the rat GPR40, and examined its effect on cytosolic free calcium concentration ([Ca2+]i) in primary rat β-cells by Fluo-3 intensity under confocal microscopy recording. Downregulation of GPR40/FFA1 expression by antisense oligonucleotides was performed in pancreatic β-cells, and insulin secretion was assessed by enzyme-linked immunosorbent assay. Results LA acutely stimulated insulin secretion from primary cultured rat pancreatic islets. LA induced significant increase of [Ca2+]i in the presence of 5.6 mmol/L and 11.1 mmol/L glucose, which was reflected by increased Fluo-3 intensity under confocal microscopy recording. LA-stimulated increase in [Ca2+]i and insulin secretion were blocked by inhibition of GPR40/FFA1 expression in β-cells after GPR40/FFA1-specific antisense treatment. In addition, the inhibition of phospholipase C (PLC) activity by U73122, PLC inhibitor, also markedly inhibited the LA-induced [Ca2+]i increase. Conclusion LA activates GPR40/FFA1 and PLC to stimulate Ca2+ release, resulting in an increase in [Ca2+]i and insulin secretion in rat islet β-cells.展开更多
Perioperative glycemic control is important for reducing postoperative infectious complications. However, clinical trials have shown that efforts to maintain normoglycemia in intensive care unit patients result in dev...Perioperative glycemic control is important for reducing postoperative infectious complications. However, clinical trials have shown that efforts to maintain normoglycemia in intensive care unit patients result in deviation of glucose levels from the optimal range, and frequent attacks of hypoglycemia. Tight glycemic control is even more challenging in those undergoing pancreatic resection. Removal of lesions and surrounding normal pancreatic tissue often cause hormone deficiencies that lead to the destruction of glucose homeostasis, which is termed pancreatogenic diabetes. Pancreatogenic diabetes is characterized by the occurrence of hyperglycemia and iatrogenic severe hypoglycemia, which adversely effects patient recovery. Postoperatively, a variety of factors including surgical stress, inflammatory cytokines, sympathomimetic drug therapy, and aggressive nutritional support can also affect glycemic control. This review discusses the endocrine aspects of pancreatic resection and highlights postoperative glycemic control using a closed-loop system or artificial pancreas. In previous experiments, we have demonstrated the reliability of the artificial pancreas in dogs with total pancreatectomy, and its postoperative clinical use has been shown to be effectiveand safe, without the occurrence of hypoglycemic episodes, even in patients after total pancreatectomy. Considering the increasing requirement for tight perioperative glycemic control and the recognized risk of hypoglycemia, we propose the use of an artificial endocrine pancreas that is able to monitor continuously blood glucose concentrations with proven accuracy, and administer automatically substances to return blood glucose concentration to the optimal narrow range.展开更多
Islet transplantation as a promising treatment for type 1 diabetes has received widespread attention. Oxidative stress plays an essential role in cell injury during islet isolation and transplantation procedures. Anti...Islet transplantation as a promising treatment for type 1 diabetes has received widespread attention. Oxidative stress plays an essential role in cell injury during islet isolation and transplantation procedures. Antioxidants have been used in various studies to improve islet transplantation procedures. The present study reviews the role of oxidative stress and the benefits of antioxidants in islet transplantation procedures. The bibliographical databases Pubmed and Scopus were searched up to November 2008. All relevant human and animal in-vivo and in-vitro studies, which investigated antioxidants on islets, were included. Almost all the tested antioxidants used in the in-vitro studies enhanced islet viability and insulin secretion. Better control of blood glucose after transplantation was the major outcome of antioxidant therapy in all in-vivo studies. The data also indicated that antioxidants improved islet transplantation procedures. Although there is still insuffi cient evidence to draw definitive conclusions about the efficacy of individual supplements, the benefi ts of antioxidants in islet isolation procedures cannot be ignored.展开更多
文摘目的评价阻塞性睡眠呼吸暂停综合征(OSAS)正常糖耐量(NGT)患者持续正压通气(CPAP)治疗前后胰岛β细胞功能和胰岛素抵抗情况。方法对35例OSAS正常糖耐量(NGT)患者CPAP治疗前后,全部行口服葡萄糖耐量试验,计算治疗前后早时相胰岛素生成指数和胰岛素抵抗指数。结果 OSAS NGT患者CPAP治疗后患者早时相胰岛素生成指数上升(P<0.05),胰岛素抵抗指数下降(P<0.05)。结论 OSAS患者经过CPAP治疗后能改善胰岛素分泌,减轻胰岛素抵抗。
文摘Glucose homeostasis deficiency leads to a chronic increase in blood glucose concentration. In contrast to physiological glucose concentration, chronic super-physiological glucose concentration negatively affects a large number of organs and tissues. Glucose toxicity means a decrease in insulin secretion and an increase in insulin resistance due to chronic hyperglycemia. It is now generally accepted that glucose toxicity is involved in the worsening of diabetes by affecting the secretion of B-cells. Several mechanisms have been proposed to explain the adverse effects of hyperglycemia. It was found that persistent hyperglycemia caused the functional decline of neutrophils. Infection is thus the main problem resulting from glucose toxicity in the acute phase. In other words, continued hyperglycemia is a life-threatening risk factor, not only in the chronic but also the acute phase, and it becomes a risk factor for infection, particularly in the perioperative period.
文摘Ghrelin,a 28 amino acid peptide hormone produced by the stomach,was the first orexigenic hormone to be discovered from the periphery.The octanoyl modification at Ser3,mediated by ghrelin O-acyltransferase(GOAT),is essential for ghrelin's biological activity.Ghrelin stimulates food intake through binding to its receptor(GRLN-R) on neurons in the arcuate nucleus of the hypothalamus.Ghrelin is widely expressed throughout the body;accordingly,it is implicated in several other physiological functions,which include growth hormone release,gastric emptying,and body weight regulation.Ghrelin and GRLN-R expression are also found in the pancreas,suggesting a local physiological role.Accordingly,several recent studies now point towards an important role for ghrelin and its receptor in the regulation of blood glucose homeostasis,which is the main focus of this review.Several mechanisms of this regulation by ghrelin have been proposed,and one possibility is through the regulation of insulin secretion.Despite some controversy,most studies suggest that ghrelin exerts an inhibitory effect on insulin secretion,resulting in increased circulating glucose levels.Ghrelin may thus be a diabetogenic factor.Obesity-related type2 diabetes has become an increasingly important health problem,almost reaching epidemic proportions in the world;therefore,antagonists of the ghrelin-GOAT signaling pathway,which will tackle both energy-and glucose homeostasis,may be considered as promising new therapies for this disease.
文摘INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence （TIRF） microscopy has been employed to study insulin secretion.
文摘Nigella sativa decreases DNA damage and thereby prevents initiation of carcinogenesis in colonic tissue secondary to exposure to toxic agents such as azoxymethane. N. sativa is of immense therapeutic benefit in diabetic individuals and those with glucose intolerance as it accentuates glucose-induced secretion of insulin besides having a negative impact on glucose absorption from the intestinal mucosa. N. sativa administration protects hepatic tissue from deleterious effects of toxic metals such as lead, and attenuates hepatic lipid peroxidation following exposure to chemicals such as carbon tetrachloride.
基金Supported by Grant from Department of Education of Liaoning Province (2008810)
文摘Objective To elucidate GPR40/FFA1 and its downstream signaling pathways in regulating insulin secretion. Methods GPR40/FFA1 expression was detected by immunofluorescence imaging. We employed linoleic acid (LA), a free fatty acid that has a high affinity to the rat GPR40, and examined its effect on cytosolic free calcium concentration ([Ca2+]i) in primary rat β-cells by Fluo-3 intensity under confocal microscopy recording. Downregulation of GPR40/FFA1 expression by antisense oligonucleotides was performed in pancreatic β-cells, and insulin secretion was assessed by enzyme-linked immunosorbent assay. Results LA acutely stimulated insulin secretion from primary cultured rat pancreatic islets. LA induced significant increase of [Ca2+]i in the presence of 5.6 mmol/L and 11.1 mmol/L glucose, which was reflected by increased Fluo-3 intensity under confocal microscopy recording. LA-stimulated increase in [Ca2+]i and insulin secretion were blocked by inhibition of GPR40/FFA1 expression in β-cells after GPR40/FFA1-specific antisense treatment. In addition, the inhibition of phospholipase C (PLC) activity by U73122, PLC inhibitor, also markedly inhibited the LA-induced [Ca2+]i increase. Conclusion LA activates GPR40/FFA1 and PLC to stimulate Ca2+ release, resulting in an increase in [Ca2+]i and insulin secretion in rat islet β-cells.
文摘Perioperative glycemic control is important for reducing postoperative infectious complications. However, clinical trials have shown that efforts to maintain normoglycemia in intensive care unit patients result in deviation of glucose levels from the optimal range, and frequent attacks of hypoglycemia. Tight glycemic control is even more challenging in those undergoing pancreatic resection. Removal of lesions and surrounding normal pancreatic tissue often cause hormone deficiencies that lead to the destruction of glucose homeostasis, which is termed pancreatogenic diabetes. Pancreatogenic diabetes is characterized by the occurrence of hyperglycemia and iatrogenic severe hypoglycemia, which adversely effects patient recovery. Postoperatively, a variety of factors including surgical stress, inflammatory cytokines, sympathomimetic drug therapy, and aggressive nutritional support can also affect glycemic control. This review discusses the endocrine aspects of pancreatic resection and highlights postoperative glycemic control using a closed-loop system or artificial pancreas. In previous experiments, we have demonstrated the reliability of the artificial pancreas in dogs with total pancreatectomy, and its postoperative clinical use has been shown to be effectiveand safe, without the occurrence of hypoglycemic episodes, even in patients after total pancreatectomy. Considering the increasing requirement for tight perioperative glycemic control and the recognized risk of hypoglycemia, we propose the use of an artificial endocrine pancreas that is able to monitor continuously blood glucose concentrations with proven accuracy, and administer automatically substances to return blood glucose concentration to the optimal narrow range.
文摘Islet transplantation as a promising treatment for type 1 diabetes has received widespread attention. Oxidative stress plays an essential role in cell injury during islet isolation and transplantation procedures. Antioxidants have been used in various studies to improve islet transplantation procedures. The present study reviews the role of oxidative stress and the benefits of antioxidants in islet transplantation procedures. The bibliographical databases Pubmed and Scopus were searched up to November 2008. All relevant human and animal in-vivo and in-vitro studies, which investigated antioxidants on islets, were included. Almost all the tested antioxidants used in the in-vitro studies enhanced islet viability and insulin secretion. Better control of blood glucose after transplantation was the major outcome of antioxidant therapy in all in-vivo studies. The data also indicated that antioxidants improved islet transplantation procedures. Although there is still insuffi cient evidence to draw definitive conclusions about the efficacy of individual supplements, the benefi ts of antioxidants in islet isolation procedures cannot be ignored.
