Stereological evaluation of renal glomeruli in offspring of diabetic female rats

ABSTRACT

Although in vitro studies have shown that high concentrations of glucose can induce dysmorphogenesis of the embryonic kidney, the possible adverse effects of exposure to intrauterine hyperglycemia on kidney development, especially in regard to nephrogenesis, has not been evaluated. The aim of this study is to investigate the effects of maternal diabetes on glomeruli structures of the offspring, focusing on the following parameters glomeruli volume and number, mesangium volume, mesangial cell number and glomerular capillary volume. Before mating, fifteen female Sprague Dawley rats, divided into three groups, were diabetes induced by a single intraperitoneal dose of 65 mg/ kg streptozotocyn [STZ]. After 30 days of breast feeding, ten offsprings from each group [two per mother] were randomly selected for kidney removal. The kidneys were weighed and their tissues were processed for light microscopy. Glomerular features were evaluated quantitatively using dissection as well as the Cavalieri method and were then compared with sham and control groups. At birth, the mean body weight of diabetic mothers' offspring [DO] was significantly lower than that of the control group's offspring [CO] and sham group's offspring [SO] [p=0.001], however, the mean body weight of the 30 day-old DO was not lower than that of CO and SO [p > 0.05]. The total renal volumes, cortical volumes, glomerular mean and total volumes, total mesangeal volumes, total capillary volumes and total glomerular numbers were significantly lower in the DO than in CO and SO [p < 0.05]. The numerical density of glomeruli and mesangial cells per glomeruli were significantly greater in DO than in CO and SO [p < 0.05]. We concluded that intrauterine hyperglycemia is accompanied by a nephron deficit which may not be compensated within the first 30 days after birth