Effects of portacaval anastomosis on pancreatic islets of the rat.

The pancreatic islets of rats with surgically constructed end-to-side portacaval anastomosis were studied immunocytochemically, morphometrically, and ultrastructurally, and the plasma levels of glucose, insulin, and glucagon determined. The results of the current study show that, four weeks after surgery, hypoglycemia, normal insulinemia, and hyperglucagonemia occur and that these hematologic changes are associated with immunocytochemical and ultrastructural signs of impairment of the secretory activity of islet B cells and normal secretion pattern of the remaining islet cell types. The causes and the meaning of the hematologic and islet cell changes are discussed, and the hypothesis has been drawn that they are primarily related to the functional deterioration of the liver, which follows the diversion of the portal blood in the systemic circulation.