Histopathological, Ultrastructural and Apoptotic Changes in Diabetic Rat Placenta

Abstract

Background: The exchange of substances betweenmother and fetus via the placenta plays a vital role during development. A number of developmental disordersin the fetus and placenta are observed during diabeticpregnancies. Diabetes, together with placental apopto- sis, can lead to developmental and functional disorders. Aims: Histological, ultrastructural and apoptoticchanges were investigated in the placenta of strepto- zotocin (STZ) induced diabetic rats. Study Design: Animal experimentation. Methods: In this study, a total of 12 female Wistar Albino rats (control (n=6) and diabetic (n=6)) were used.Rats in the diabetic group, following the administrationof a single dose of STZ, showed blood glucose levelshigher than 200 mg/dL after 72 hours. When pregnancy was detected after the rats were bred, two piecesof placenta and the fetuses were collected on the 20th day of pregnancy by cesarean incision under ketamine/ xylazine anesthesia from in four rats from the controland diabetic groups. Placenta tissues were processedfor light microscopy and transmission electron microscopy (TEM). Hematoxylin-eosin (HE) and periodic acid Schiff-diastase (PAS-D) staining for light micro- scopic and caspase-3 staining for immunohistochemical investigations were performed for each placenta.Electron microscopy was performed on thin sectionscontrasted with uranyl acetate and lead nitrate. Results: Weight gain in the placenta and fetuses of dia- betic rats and thinning of the decidual layer, thickeningof the hemal membrane, apoptotic bodies, congestionin intervillous spaces, increased PAS-D staining in decidual cells and caspase-3 immunoreactivity were observed in the diabetic group. After the ultrastructuralexamination, the apoptotic appearance of the nuclei oftrophoblastic cells, edema and intracytoplasmic vacuolization, glycogen accumulation, dilation of the endoplasmic reticulum and myelin figures were observed.In addition, capillary basement membrane thickening,capillary endothelial cells chromatin condensation inthe nucleus and corrugation of the nucleus were found. Conclusion: Diabetes causes histomorphometric, ultrastructural and apoptotic changes in rat placenta.