THE MECHANISM OF ACTION OF ALLOXAN ON BLOOD SUGAR

Abstract

The triphasic modification of blood sugar was studied after intraven. injn. of alloxan to the dog (100 mg. of alloxan/kg.) and to Bufo arenarum Hensel (200 mg./kg.). The initial hyperglycemia did not appear in hepatectomized dogs or toads nor in eviscerated dogs, but did in adrenalectomized dogs or toads and in hypophysec-tomized toads. Nine dogs depancreatized 1/2 hr. before alloxan injn. showed marked hypoglycemia 1-5 hrs. later. Seven dogs depancreatized 24-48 hrs. before injn. showed no hypoglycemia. In pancreatectomized toads, immediate injn. prevented or decreased hyperglycemia for 24 hrs. Duodeno-pancreas of dogs was grafted to pancreatectomized dogs. Pancreas from dogs inj. with alloxan 24-48 hrs. before extraction and grafting reduced insulin secretion. The final rise of blood sugar could reach higher values than those usually seen after pancreatectomy. The initial hyperglycemia is attributed to a direct action on the liver, the secondary hypoglycemia to an extrapancreatic effect, probably lack of glucose production by the liver and the final hyperglycemia to destruction of the B cells of the islets of Langerhans.