OFFSPRING OF STREPTOZOTOCIN-DIABETIC RATS - SIZE CHANGES IN LANGERHANS ISLETS WITH TIME AFTER BIRTH

It has been demonstrated that, in the diabetic rat, pregnancy and lact ation are severely altered: in this study, we have measured the size o f Langerhans islets of rat pups, the offspring of experimental diabeti c mothers and nondiabetic controls. Diabetes was induced through strep tozotocin administration (dose, 60 mg/kg body wt.). This drug was inje cted in every animal; their blood sugar was measured 1 week later (Hae mo-Glukotest, Boehringer Mannheim), and they were then separated into three groups according to their fasting blood sugar levels: (a) severe diabetics (above 16.5 mM/l); (b) mild diabetics (6.5-16.5 mM/l); and (c) nondiabetic normals. They received insulin therapy (2-4 I.U./day) as the mild diabetics exhibited a slightly higher than normal fasting blood sugar, and the diabetic ones, above 15 mM/l. The areas of Langer hans islets of pups were measured 1 and 5 days after parturition; panc reas sections were dyed (haematoxylin-eosin) and morphometry was then performed using a digitalized magnetic tabloid connected to a Zeiss Mo rphomat 30 (Kontron). On the first day after parturition, the pancreas section areas in pups from mildly and severely diabetic mothers were smaller than those in neonates from nondiabetic controls (P < 0.001). The areas in neonates from severely diabetic mothers showed a more int ense decrease than those from mildly diabetic animals (P < 0.01). On d ay 5 after delivery, the areas of Langerhans islets in offspring from normal mothers decreased and those in pups from diabetic mothers tende d to normalize (P < 0.01), particularly those from the severely sick g roup (P < 0.01). We conclude that after parturition the offspring is n o longer exposed to the high blood sugar levels found in both diabetic groups of mothers, thereby no hyperinsulinemia is needed; as time ela pses, then, the area of their Langerhans islets tends to normalization . (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.