Tolbutamide hypoglycemia in acutely depancreatized dogs.

The hypoglycemic activity of tolbutamide and related compounds is well established; however, their mode of action is still debated. Several theories have been postulated (1-5). One of the most widely held is that tolbutamide stimulates the beta cells of the pancreas and the resulting insulin secretion produces the fall in blood sugar (1). The reported ineffectiveness of tolbutamide in depancreatized animals (1) and humans (6) is taken as strong evidence for this theory. With few exceptions these studies were done sometime after recovery from the pancreatectomies. One of us (M.K.) in the past studied the possible pancreatropic effect of another substance, i.e., anterior pituitary growth hormone (7). It was observed that growth hormone had a hypoglycemic effect in acutely depancreatized dogs but not in dogs several days after pancreatectomy. Accordingly, it was thought worthwhile to study the effect of tolbutamide in acutely depancreatized dogs.