Histological analysis of kidneys and placentas
Kidneys and placentas of rats were harvested from the dams on GD 20.5. The tissues were then fixed in 10% buffered formalin overnight at 4°C. Processed tissues were embedded in paraffin. Serial sections (5 µm) were cut from each uteroplacental unit and serial sections (3 µm) were cut from each kidney. The sections of kidney were deparaffinized, rehydrated and stained with Hematoxylin and Eosin and periodic acid-Schiff for histopathological assessment of renal alterations. The degree of glomerular pathology was assessed by a blinded observer based on criteria and scoring methods adapted from prior studies (Li et al., 2007; Strevens et al., 2003) and after consultation with an experienced renal pathologist at Xiangya Hospital. For each kidney, 20 glomeruli were individually scored and the severity of glomerular pathology was determined from the mean score for each kidney. The sections of placentas were de-waxed, hydrated, and stained with Hematoxylin and Eosin, and the morphology was examined by analyzing 10 fields in 5 sections from 3 placentas in each rat under light microscopy.