[Pathophysiology in diabetes after major resection of the pancreas, with special reference to insulin metabolism and glucagon secretion (author's transl)].

Recently, major resection of the pancreas has been carrier out not only to treat pancreatic carcinoma but also for benign pancreatic diseases. Dragstedt reported that the amount of insulin required to control glycosuria after partial pancreatectomy is much greater than that needed after total pancreatectomy. Although it is thought that diabetes after partial pancreatectomy is considerably different from that after total pancreatectomy, these pathophysiological changes have not been investigated in detail. In the present experiment, changes in carbohydrate and insulin metabolism and glucagon secretion were studied in dogs in order to elucidate the pathophysiology in diabetes after major resection of the pancreas. Immediately after resection of 90% or more of the entire pancreas, diabetes occurred with absolute insulin deficiency, being accompanied by decreased function of the anti-insulin system with poor secretion of glucagon and delayed recovery of blood sugar after the insulin load. Moreover, the half-life of insulin in this group was much longer than that in normal dogs and close to that after total pancreatectomy. These results could explain that the dosage of insulin required to control blood sugar after resection of 90% or more of the entire pancreas was close to that after total pancreatectomy. Six weeks or more after resection of 70 to 90% of the entire pancreas, so-called Sandmeyer's diabetes gradually as a consequence of a decrease in insulin secretion and an increase in glucagon secretion from the remnant pancreas. After the insulin load, glucagon secretion markedly increased and recovery of blood sugar from the insulin hypoglycemia was good, showing hyperfunction of the anti-insulin system. Moreover, the half-life of insulin gradually lengthened but was still shorter than that after total pancreatectomy. These results could well explain the fact that the insulin dosage required to control blood sugar in Sandmeyer's diabetes was 3 to 4 times more than that needed after total pancreatectomy. After resection of less than 70% of the entire pancreas, diabetes did not occur throughout a period of post-operative observation of up to 66 weeks. After the insulin load, glucagon secretion and recovery rate of blood sugar from the insulin hypoglycemia were maintained well, showing normal function of the anti-insulin system, and the half-life of insulin was also within the normal range.