Acarbose feeding increases pancreatic islet blood flow in obese glucose-intolerant Otsuka Long-Evans Tokushima fatty rats.

摘要

To the Editor:Islets of Langerhans have a unique vascular system independent of exocrine tissue in the pancreas, and islet blood flow is meticulously regulated by metabolic, neural, hormonal, and local factors. A rodent model of type 2 diabetes mellitus including Otsuka Long-Evans Tokushima fatty (OLETF) rats exhibits islet blood hyperperfusion, although its significance remains to be clarified at present. Acarbose, a potent competitive inhibitor of a-glucosidase in the intestinal brash border and amylase in pancreatic juice, delays disaccharide and carbohydrate digestion and reduces postprandial glycemia and insulinemia accordingly.4 Although a-glucosidase inhibitors such as acarbose and voglibose are not absorbed from the gastrointestinal tract and thus seem to have no direct effects on pancreatic islets in vivo, voglibose feeding reduced oxidative damages and loss of p cells in spontaneously diabetic Goto-Kakizaki rats.5 To further clarify the effect of a-glucosidase inhibitors on pancreatic islets,we investigated the effects of acarbose feeding on islet blood flow in OLETF rats, which have a long prediabetic glucose-intolerant period when acarbose seems to be particularly effective.