Rate of insulin infusion with a minipump required to maintain a normoglycemia in diabetic rats.

It is notoriously difficult to normalize plasma glucose profiles for a prolonged time by conventional methods of insulin administration in both human and animal diabetics. The present study was conducted to determine the dosage of insulin needed to maintain prolonged and around-the-clock normoglycemia as well as normoglucagonemia in streptozotocin diabetic rats with the Alzet osmotic minipump which releases insulin constantly for 14 days. A minipump was inserted into the peritoneal cavity of diabetic rats under chloral hydrate anesthesia. Diabetic rats were treated with several consecutive minipumps and body weights, plasma glucose, and plasma glucagon levels were monitored. Plasma glucose concentrations were determined every 8 hr for several days and were found essentially identical during the active life of the minipump. An average insulin dose of 8.0 to 9.0 U/kg/day was required to normalize body weights, plasma glucose, and plasma glucagon of streptozotocin diabetic rats treated with the Alzet osmotic minipump Model 2002.