Liver X receptors (LXRs) alpha and beta, transcription factors of a nuclear hormone receptor family, are expressed in pancreatic islets as well as glucagon-secreting and insulin-secreting cell lines. Culture of pancreatic islets or insulin-secreting MIN6 cells with a LXR specific agonist T0901317 caused an increase in glucose-dependent insulin secretion and islet insulin content. The stimulator...

Insulin and glucagon release from monolayer pancreatic islet cell cultures were inhibited in a dose-response fashion by various enkephalins. Morphine, however, stimulated insulin and glucagon release. Both effects were blocked by naloxone, while naloxone alone had no effect. In isolated and denervated islet cells, opiates directly influence secretion from islet cells.

Endothelial cells are considered to be essential for normal pancreatic β-cell function. The current study attempted to demonstrate the role of insulin receptor substrate-2 (Irs2) in endothelial cells with regard to insulin secretion. Endothelial cell-specific Irs2 knockout (ETIrs2KO) mice exhibited impaired glucose-induced, arginine-induced, and glucagon-induced insulin secretion and showed glu...

abstract reactive oxygen species and oxidative stress impair β-cell function and reduce insulin secretion. it has been shown that progesterone and cilostazol possess antioxidant properties. the present study was aimed to investigate in vitro pretreatment effect of progesterone and cilostazol on insulin secretion as well as their protective effects against hydrogen peroxide-induced oxidative str...

Pancreatic islets manage elevations in blood glucose level by secreting insulin into the bloodstream in a pulsatile manner. Pulsatile insulin secretion is governed by islet oscillations such as bursting electrical activity and periodic Ca2+ entry in β-cells. In this report, we demonstrate that although islet oscillations are lost by fixing a glucose stimulus at a high concentration, they may be...

Kowluru, Anjaneyulu. Regulatory roles for small G proteins in the pancreatic -cell: lessons from models of impaired insulin secretion. Am J Physiol Endocrinol Metab 285: E669–E684, 2003;10.1152/ajpendo. 00196.2003.—Emerging evidence suggests that GTP-binding proteins (G proteins) play important regulatory roles in physiological insulin secretion from the islet -cell. Such conclusions were drawn...

It is unknown whether a scaffold containing both small intestinal submucosa (SIS) and mesenchymal stem cells (MSCs) for transplantation may improve pancreatic islet function and survival. In this study, we examined the effects of a SIS-MSC scaffold on islet function and survival in vitro and in vivo. MSCs and pancreatic islets were isolated from Sprague-Dawley rats, and SIS was isolated from Ba...

Miura, Yoshikazu, and Hisao Matsui. Glucagon-like peptide-1 induces a cAMP-dependent increase of [Na ]i associated with insulin secretion in pancreatic islet -cells. Am J Physiol Endocrinol Metab 285: E1001–E1009, 2003; 10.1152/ajpendo.00005.2003.—Glucagon-like peptide-1 (GLP-1) elevates the intracellular free calcium concentration ([Ca2 ]i) and insulin secretion in a Na -dependent manner. To i...

Type 2 diabetes is characterized by insulin resistance, hyperglycemia, and progressive β cell dysfunction. Excess glucose and lipid impair β cell function in islet cell lines, cultured rodent and human islets, and in vivo rodent models. Here, we examined the mechanistic consequences of glucotoxic and lipotoxic conditions on human islets in vivo and developed and/or used 3 complementary models t...

objective(s): ghrelin is a peptide hormone that has been shown to have numerous central and peripheral effects. the central effects including gh secretion, food intake, and energy homeostasis are partly mediated by kiss1- kissr signaling pathway. ghrelin and its receptor are also expressed in the pancreatic islets. ghrelin is one of the key metabolic factors controlling insulin secretion from t...