Effects of E coli endotoxin on pancreatic hormones and blood flow

Studies were performed on anesthetized dogs to determine the relationship between endotoxin-induced alterations in pancreatic blood flow (PBF) and hormones that originate partially or completely from the pancreas. PBF was estimated in six dogs by radioactive microspheres (praeendoxin, 25 and 240 minutes postendotoxin). Insulin, glucagon, pancreatic polypeptide (PP), and somatostatin-like immunoreactivity (SLI) were assayed in arterial and portal venous blood. Cardiac output and mean arterial blood pressure (MABP) decreased 25 minutes after endotoxin administration (50% and 40%, respectively) and returned toward normal levels by four hours. However, there was 74% decrease in PBF at 25 minutes and a further drop four hours after endotoxin. Hormonal responses were characterized by a short-lived increase in arterial insulin, corresponding to a transient increase in blood glucose. Insulin release increased shortly after endotoxin. Arterial glucagon and PP increased two to five hours after endotoxin. There was a suggestion that the increase in PP was of nonpancreatic origin. Little change in plasma SLI was noted following endotoxin. Thus, it appears that endotoxin altered the release of different pancreatic hormones with a variable time courses.