The effects of subdiabetogenic streptozotocin doses on rat beta cell volume and functions.

The influence of a single i.v. injection of 30 mg/kg streptozotocin (SZ) into female Wistar rats on plasma glucose, pancreatic insulin content, volume and function of the remaining beta-cells has been investigated. 14 days after SZ treatment most animals remained normoglycemic; only about 15% showed permanent hyperglycemia. The pancreatic insulin content in normoglycemic rats was reduced to 30%, whereas in hyperglycemic rats only 6% of control values could be detected. The remaining beta-cell volume was comparable in the two groups, indicating no correlation between pancreatic insulin content and residual beta-cell volume. The glucose- and IBMX-stimulated insulin release of islets isolated from normoglycemic cats 14 days after SZ application was not significantly altered whereas the islets insulin content of SZ treated animals was significantly lowered in comparison to controls.