Gender Differences In Calcium Oxalate Stones In Rats And Its Correlation With Osteopontin

Objective: To investigate the effect of sexual difference on renal stone formation of rat model with ethylene glycol-induced renal calculi and the correlation between sexual difference and the expression of osteopontin(OPN),and to detect the mechanism that sexual difference lead to kidney calculi.Methods: Twenty four healthy rats(twelve males and twelve females)were randomly allocated to one of two treatment regimens: feeding normal saline(six males and six females)or 1% ethylene glycol(six males and six females)for four weeks.Killed rats by overdose anesthetics and extracted their left and right kidneys.After HE staining,kidney tissues were observed and calculus crystal in kidney tubular lumens were evaluated by polarizing microscope,and the expression of OPN from each male and female group were detected by Western blot.Results: HE staining showed the structures of glomerulus and renal tubules in male and female control groups are normal,and abnormal changes can’t be found in renal tubular lumens;extensive scattered crystals can be seen in a part of renal tubular lumens of female ethylene glycol rats;and in most renal tubular lumens of male ethylene glycol rats,more transparent、irregular flaky crystals were observed in cortex than medulla,and they mainly located in proximal and distal convoluted tubules.The grade of calculus crystal in female ethylene glycol rats was less than males’(P<0.05),furthermore,Western blot showed the expression of OPN protein in male ethylene glycol rats was more than females’(P<0.05).Conclusions: Sexual difference can influence renal stone formation and male rats are more likely to form renal stone than females,and the mechanism may correlates with OPN.