Abstract
A radioimmunoassay (RIA) method for somatostatin (SRIF) utilizing rabbit antiserum against synthetic SRIF coupled with human serum α-globulin is described. Synthetic Nα-tyrosylated SRIF was labelled with 125I using the lactoperoxidase method and purified on a Sephadex G-10 column. This assay system was highly specific for SR IF and did not cross-react with hypothalamic trophic hormones, pituitary trophic hormones or gastrointestinal hormones.
The effect of streptozotocin induced diabetes on the SRIF content was examined in the pancreas, the pancreatic islets, as well as the hypothalamus of rats. SRIF content in both the pancreas and islets of the diabetic rats was shown by RIA to have significantly increased. However, content in the hypothalamus of the diabetic rats did not differ from that of the control. The physiological and pathophysiological significance of the SRIF changes remains to be determined.
