Effects of glucose and some oral hypoglycemic agents upon the plasma glucose and immuno-reactive insulin (IRI) in normal and streptozotocin induced diabetic rat.

An investigation has been made to see the effect of oral hypoglycemic agants on the blood sugar (BS) and plasma Immuno-Reactive Insulin (IRI) in normal and streptozotocin diabetic rats. Plasma IRI was significantly reduced in a streptozotocin treated diabetic rat 8 weeks after streptozotocin injection. In normal rats oral administration of Sodium tolbutamide (TOL) and Glybenclamide (GLI) produced a significant fall in BS and a concurrent increase in plasma IRI, but phenformin (PHE) was without any effect on both these parameters. Unlike normal rats streptozotocin treated diabetic rats did not show lowering of BS and increase in plasma IRI following TOL and GLI. PHE, however, did produce a significant fall in BS. Oral glucose load did show a typical glucose tolerance curve and insulin release in normal rats. However, in the diabetic rats there was no significant increase in plasma IRI following glucose load. It is therefore concluded that streptozotocin treated diabetic rats differ from the maturity onset diabetic as regards the responses of TOL and GLI are concerned and this animal model can therefore be useful in differentiating the two types of oral hypoglycemic agents.