Diabetogenic Effects of Streptozotocin in Rhesus Monkeys

Streptozotocin was administered to twelve rhesus monkeys in single intravenous doses of 30, 45, or 60 mg. per kg. Post-treatment study of plasma glucose and immunoreactive insulin levels and pancreatic histology confirmed previous observations in lower animals that streptozotocin produces a diabetic-like state due to its cytotoxic action on pancreatic beta cells. In contrast to its reported effect in rodents, however, streptozotocin in monkeys was somewhat more variable in its diabetogenic action and appeared to have a narrower margin of safety between diabeto genesis and toxicity. Of seven animals given 45 mg. per kg., five developed hyperglycemia and relative hypoinsulinemia and a sixth had impaired glucose tolerance. Two monkeys, both receiving 60 mg. per kg., became frankly diabetic while all three receiving 30 mg. per kg. showed no alteration in glucose tolerance.