Diabetes, Vol 29, Issue 7 536-546, Copyright © 1980 by American Diabetes Association
Streptozotocin diabetes in the monkey: plasma levels of glucose, insulin, glucagon, and somatostatin, with corresponding morphometric analysis of islet endocrine cells
CW Jones, WA Reynolds and GE Hoganson
Streptozotocin (STZ) was administered to 20 female rhesus monkeys at a dose
of between 30 and 55 mg/kg. Depending on the severity of the resultant
diabetic-like state, these animals were divided into two groups:
insulin-dependent monkeys requiring daily insulin injections and
carbohydrate-disturbed animals not requiring insulin. STZ-treated monkeys
exhibited significantly higher fasting glucose levels or increased glucose
disappearance times after an intravenous glucose tolerance test than did
controls. In the insulin-dependent monkeys, fasting plasma glucagon levels
were elevated when compared with the carbohydrate-disturubed or control
monkeys. Glucagon levels did not differ between carbohydrate-disturbed and
control animals. Fasting somatostatin levels were also significantly
elevated in insulin-dependent animals when compared with controls.
Morphometric analysis was performed on the alpha, beta, and delta cell
populations of the pancreatic islets in three control and three diabetic
animals. Significant decreases in beta cell percent volume and numerical
percent and increases in both alpha and delta cell percent volume and
numerical percent were observed in relation to control values after STZ
diabetes lasting from 17 to 31 mo. Thus, the diabetic-like state induced by
STZ in the monkey resembles juvenile-onset human diabetes mellitus with
respect to plasma hormone levels and to morphometric changes in the islets
of Langerhans.