Effect of animal sex on experimental ciclosporin nephrotoxicity

Experimental ciclosporin (CSA) nephrotoxicity is reported to be more severe in male versus female rodents. To investigate these sex differences further, groups of male and female Sprague-Dawley rats were pair fed and given either CSA 50 mg/kg or olive oil vehicle by gavage daily for 5 days. Both groups of treated animals showed azotemia and depression of CIn but there were no sex differences. CSA levels were 5,820 ng/ml in females and 6,480 ng/ml in males (p = NS). Although CSA did not produce enzymuria in either sex, females showed more extensive proximal tubular cell vacuolization. Conclusion: Female Sprague-Dawley rats are equally as susceptible to CSA nephrotoxicity as males. Strain differences or experimental design may account for apparently conflicting results in the literature.