Partial pancreatectomy in the rat and subsequent defect in glucose- induced insulin release. J Clin Invest

reduction of B cell mass in rats, 90 % partial pancrea-tectomies were performed. For the 6 wk following sur-gery moderate hyperglycemia was maintained in the fed state but there were no differences in body weight nor plasma insulin concentrations compared with sham-pancreatectomized controls. 8-10 wk following surgery regeneration of the remnant was evident with remnant weight being 26%, B cell mass being 42%, and non-B cell mass being 47 % of values found for control whole pancreas. There were comparable in-creases in the remnant content of insulin, glucagon, and somatostatin. Following meal challenges, intra-peritoneal and intravenous glucose tolerance tests and intravenous arginine challenge given 6-7 wk after sur-gery, the insulin responses to glucose were blunted or absent but the responses following the meals or argi-nine were intact. Similarly, when the pancreatic rem-nant was perfused in vitro, insulin release after chal-lenge with 300 mg/dl glucose was markedly reduced whereas intact responsiveness to 10 mM arginine was retained. These data suggest that the chronic stimu-lation of a reduced B cell mass can lead to a selective loss of glucose-induced insulin secretion