THE BLOOD-FLOW IN PANCREATICODUODENAL GRAFTS IN RATS - INHIBITION OF NITRIC-OXIDE SYNTHASE PREFERENTIALLY DECREASES ISLET BLOOD-FLOW

In this study normoglycemic inbred Wistar-Furth rats were implanted wi th a syngeneic pancreatico-duodenal graft, i.e. a denervated pancreas. The blood flow to the intact native pancreas and to the transplanted gland was measured with a microsphere technique in anesthetized rats 2 weeks after transplantation. The animals were given an intravenous in jection with saline alone, N-G-nitro-L-arginine (25 mg/kg body weight) or sodium nitroprusside (10 mu g/kg body weight) 10 min before blood flow measurements. Administration of N-G-nitro-L-arginine increased me an arterial blood pressure and caused a pronounced decrease in whole p ancreatic blood flow in both the native and transplanted gland. The is let blood flow was more markedly decreased by N-G-nitro-L-arginine in both the native and transplanted pancreas, and constituted about 4% of whole pancreatic blood flow compared with 10% in the control animals. Sodium nitroprusside markedly decreased mean arterial blood pressure, but did not affect pancreatic or islet blood flow in any of the gland s. It is concluded that inhibition of nitric oxide synthase causes a p referential decrease in islet blood flow both in the native pancreas a nd in the transplanted pancreas. This suggests that nitric oxide which affects islet blood flow is mainly endothelial-derived, and does not emanate from external nervous fibers.