The long-chain fatty acid receptor GPR40 plays an important role in potentiation of glucose-induced insulin secretion (GIIS) from pancreatic β-cells. Previous studies demonstrated that GPR40 activation enhances Ca release from the endoplasmic reticulum (ER) by activating inositol 1,4,5-triphosphate (IP3) receptors. However, it remains unknown how ER Ca release via the IP3 receptor is linked to GIIS potentiation.
View Article and Find Full Text PDFBackground: Enhanced Recovery After Surgery (ERAS) protocols are multimodal perioperative care pathways designed to achieve early recovery after surgical procedures by maintaining preoperative organ function and reducing profound stress responses following surgery [Wilmore and Kehlet: BMJ 2001; 322(7284): 473-6]. Glucagon-like peptide-1 receptor agonists (GLP-1RAgs), such as liraglutide, have recently been widely used as antidiabetic agents in patients with type 2 diabetes (T2D) because they maintain blood glucose at an ideal level throughout the day, including during postprandial periods, thereby improving hypoglycemia and body weight more than insulin therapies. Additionally, the administration of liraglutide may exert cardiovascular, renal, and cerebral protective effects in T2D patients.
View Article and Find Full Text PDFProcyanidins, the main ingredient of apple polyphenols, are known to possess antioxidative and anti-inflammatory effects associated closely with the pathophysiology of insulin resistance and type 2 diabetes. We investigated the effects of orally administered apple procyanidins (APCs) on glucose metabolism using diabetic ob/ob mice. We found no difference in body weight or body composition between mice treated with APCs and untreated mice.
View Article and Find Full Text PDFAims/introduction: Src, a non-receptor tyrosine kinase, regulates a wide range of cellular functions, and hyperactivity of Src is involved in impaired glucose metabolism in pancreatic β-cells. However, the physiological role of Src in glucose metabolism in normal, unstressed β-cells remains unclear. In the present study, we investigated the role of Src in insulin secretion and glucose metabolism.
View Article and Find Full Text PDFAims/introduction: Chronic hyperlipidemia impairs pancreatic β-cell function, referred to as lipotoxicity. We have reported an important role of endogenous reactive oxygen species (ROS) overproduction by activation of Src, a non-receptor tyrosine kinase, in impaired glucose-induced insulin secretion (GIIS) from diabetic rat islets. In the present study, we investigated the role of ROS production by Src signaling in palmitate-induced dysfunction of β-cells.
View Article and Find Full Text PDFWe report characteristic magnetic resonance (MR) image findings in a case of Sheehan's syndrome. A 37-year-old woman experienced complications of retained placenta and massive bleeding (3600 g) during delivery of a full-term baby. A pituitary function test demonstrated panhypopituitarism.
View Article and Find Full Text PDFWe previously demonstrated that impaired glucose-induced insulin secretion (IS) and ATP elevation in islets of Goto-Kakizaki (GK) rats, a nonobese model of diabetes, were significantly restored by 30-60-min suppression of endogenous reactive oxygen species (ROS) overproduction. In this study, we investigated the effect of a longer (12 h) suppression of ROS on metabolism-secretion coupling in β-cells by exposure to tempol, a superoxide (O2(-)) dismutase mimic, plus ebselen, a glutathione peroxidase mimic (TE treatment). In GK islets, both H2O2 and O2(-) were sufficiently reduced and glucose-induced IS and ATP elevation were improved by TE treatment.
View Article and Find Full Text PDFIn pancreatic β-cells, glucose-induced mitochondrial ATP production plays an important role in insulin secretion. The mitochondrial phosphate carrier PiC is a member of the SLC25 (solute carrier family 25) family and transports Pi from the cytosol into the mitochondrial matrix. Since intramitochondrial Pi is an essential substrate for mitochondrial ATP production by complex V (ATP synthase) and affects the activity of the respiratory chain, Pi transport via PiC may be a rate-limiting step for ATP production.
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