The expression of adiponectin receptors is demonstrated in human and rat pancreatic beta cells, in which globular (g) Axl adiponectin rescues rat beta cells from cytokine and fatty acid-induced apoptosis. The aim of our examine was to evaluate no matter whether adiponectin features a direct result on insulin secretion as well as metabolic pathways concerned. Purified human pancreatic islets and rat beta cells (INS-1E) have been exposed (1 h) to g-adiponectin, and glucose-induced insulin secretion was measured. A substantial boost in glucose-induced insulin secretion was observed in the presence of TMP269 g-adiponectin (one nmol/l) with respect to manage cells in both human pancreatic islets (n = five, p < 0.05) and INS-1E cells (n = five, p < 0.001). The effect of globular adiponectin on insulin secretion was independent of AMP-dependent protein kinase (AMPK) activation or glucose oxidation.
In contrast, g-adiponectin significantly increased oleate oxidation (n = 5, p < 0.05), plus the result of g-adiponectin (p < 0.001) on insulin secretion by INS-1E was significantly reduced from the presence of etomoxir (1 mu mol/l), an inhibitor of fatty acid beta oxidation. g-Adiponectin potentiates glucose-induced insulin secretion in the two human pancreatic islets and rat beta cells via an AMPK independent pathway. Increased fatty acid oxidation rather than augmented glucose oxidation is the mechanism responsible. Overall, our data indicate that, in addition to its anti-apoptotic action, g-adiponectin has another direct impact on beta cells by potentiating insulin secretion. Adiponectin, therefore, in addition to its well-known impact on insulin sensitivity, has important effects at the pancreatic level.