SOMATOSTATIN RECEPTOR-EFFECTOR SYSTEM IN RAT PANCREATIC ACINAR MEMBRANES AFTER SUBTOTAL ENTERECTOMY

In the present study we found that exocrine pancreatic hyperplasia obs erved after proximal small bowel resection is accompanied by an increa se in pancreatic somatostatin (SS) content at 1 mo and an increase in the number of SS receptors at 2 wk and 1 mo after intestinal surgery. At 6 mo after small bowel resection SS content and SS receptors had re turned to control values. However, the original increase in SS recepto r number was accompanied by a decrease in the ability of SS to inhibit forskolin-stimulated adenylyl cyclase (AC) activity. In addition, the ability of 5'-guanylylimidodiphosphate (a nonhydrolyzable GTP analogu e) to inhibit SS receptor binding was decreased in pancreatic acinar m embranes from enterectomized rats at 2 wk and 1 mo after jejunoileal r esection. These data suggest that there is an abnormality in the integ rity of SS receptor binding site-G protein interactions and would expl ain the decreased inactivation of AC by SS at 2 wk and 1 mo after prox imal small bowel resection.