INSULIN THERAPY PREVENTS SPONTANEOUS-RECOVERY FROM STREPTOZOTOCIN-INDUCED DIABETES IN SYRIAN-HAMSTERS - AN AUTORADIOGRAPHIC AND IMMUNOHISTOCHEMICAL STUDY

Streptozotocin (Sz) given as a single dose of 50 mg/kg body wt. caused severe diabetes in Syrian hamsters. However, the level of blood glucose decreased gradually after 21 days post-Sz and reached the near normal level at 70 days in 90% of hamsters. The recovery from diabetes was associated with the regeneration of the β-cells of islets and a reduction in the initially increased number of α- and δ-cells. Daily treatment of diabetic hamsters with insulin was associated with the persistence of severe diabetes, lack of or minimal tendency for β-cell regeneration and sustained hyperplasia of α- and δ-cells in 90% of hamsters. Insulin also inhibited DNA synthesis (as measured by incorporation of tritiated thymidine), in ductal, ductular and acinar cells in Sz-pretreated hamsters but not in normoglycemic control hamsters treated with insulin alone. The results demonstrate a deleterious effect of exogenous insulin in the course of Sz-induced diabetes in hamsters. © 1990 Springer-Verlag.