Neonatally Induced Mild Diabetes in Rats and Its Effect on Maternal, Placental, and Fetal Parameters

Abstract

The aim of this study was to assess placental changes and reproductive outcomes in neonatally induced mild diabetic dams and fetal development in their offspring. At birth, female rats were assigned either to control or diabetic group (100 mg of streptozotocin/Kg, subcutaneously). At adulthood, the female rats were mated. During pregnancy, the blood glucose levels and glucose and insulin tolerance tests were performed. At term, maternal reproductive outcomes, fetal and placental weight, and placental morphology were analyzed. Diabetic rats had smaller number of living fetuses, implantations and corpora lutea, and increased rate of embryonic loss. Placenta showed morphometric alterations in decidua area. Our results showed that mild diabetes was sufficient to trigger alterations in maternal organism leading to impaired decidua development contributing to failure in embryonic implantation and early embryonic losses. Regardless placental decidua alteration, the labyrinth, which is responsible for the maternal-fetal exchanges, showed no morphometric changes contributing to an appropriate fetal development, which was able to maintain normal fetal weight at term in mild diabetic rats. Thus, this experimental model of diabetes induction at the day of birth was more effective to reproduce the reproductive alterations of diabetic women.

Histopathological, Ultrastructural and Apoptotic Changes in Diabetic Rat Placenta

“…Despite placentomegaly, decreases in placental blood flow in parallel with fetal growth retardation have been previously reported as a result of increased erythropoietin and secondary polycythemia caused by hypoxia in the fetus. A similar pattern of fetal growth retardation caused by decreased placental blood flow has been correlated with placentomegaly in pregnant women living at high altitudes and using alcohol (6). In this study, histologically distinctive differences were detected in the placenta of diabetic rats with respect to rats in the control group.…”

Extracellular HSP70 levels in diabetic environment in rats

“…Nevertheless, a number of studies carried out in our laboratory found increased rates of pre-and postimplantation embryo losses and embryonic death (resorption), reduced number of live fetuses, and maternal weight gain during diabetic pregnancy. These alterations are due to metabolic changes caused by hyperglycemic peaks during pregnancy (Kiss et al 2009;Damasceno et al 2011;Iessi et al 2010;Saito et al 2010;Dallaqua et al 2012;Sinzato et al 2012). The divergent results shown in our study, which does not reinforce an effect of diabetes on the reproductive performance of rats, is possibly explained by mating time.…”

“…In addition, diabetes causes intrauterine growth restriction (IUGR), reduces the number of corpus luteum and embryo implantation, and increases the rates of pre-and postimplantation embryo losses (Sinzato et al 2012). Iessi et al (2010) found intrauterine growth restriction (IUGR) in fetuses from rats with induced mild diabetes.…”

Effect of Bauhinia holophylla treatment in Streptozotocin-induced diabetic rats

“…before glucose administration. Blood glucose concentrations were measured at 0 (previous administration of glucose solution/plant extractfasting glucose), 30, 60 and 120 min (Mello et al 2001, Sinzato et al 2012. Glucose responses during the OGTT were evaluated by estimation of the total area under the curve (AUC), using the trapezoidal method (Tai 1994).…”