Sex-related differences in renal toxicodynamics in rodents

INTRODUCTION

An issue yet to be addressed, in the investigation of the xenobiotic toxicity, is a detailed characterization of the sex differences in toxicological responses. The 'sex issue' is particularly significant in nephrotoxicology as the kidney is a relevant target organ for xenobiotics and few studies have approached this subject in the past. There is a strong need to improve our understanding regarding the influence of sex in toxicology, given their increased requirement to establish the limits of exposure to chemicals in the environment and at work.

AREAS COVERED

In this review, the authors provide the reader with the current knowledge of sex differences in kidney toxicity for rats and mice. To make the review easier to consult, these studies have been organized according to the class of xenobiotic.

EXPERT OPINION

From the analysis of the present knowledge emerges a dramatic need for information on sex differences in xenobiotics toxicity. Although animals are reasonably good predictors of adverse renal effects in patients, there is need to identify alternative methods (e.g. in vitro/ex vivo) to better study sex differences in organ toxicity.

Different effects of (CIS+TRANS) 1,3-dichloropropene in renal cortical slices derived from male and female rats

Nephrotoxic effects of 1,3-dichloropropene (cis and trans isomers mixture) was investigated in vitro by means of renal cortical slice model in male and female rats, including treatment with metabolism modifiers as an inducer of cytochrome P-450 1A class (beta-naphthoflavone), a reduced glutathione depleting (DL-buthionine-[S,R]-sulfoximine), an inhibitor of gamma-glutamyl-transferase (AT-125) and inhibitor of cysteine conjugate beta-lyase (aminooxiacetic acid). Dose-dependent decrease of p-aminohippurate uptake was observed in male renal cortical slices. Only the high doses (3.0 and 4.0 x 10(-4) M) caused a significant loss of organic anion uptake in females. beta-Naphthoflavone and alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (AT-125) partially, but significantly, reduced organic anion loss in males. In females, DL-buthionine-[S,R]-sulfoximine significantly increased in females but in males loss of organic anion accumulation caused by 1,3-dichloropropene. Aminooxyacetic acid did not ameliorate 1,3 D effects in vivo and in vitro in male rats. It appeared very toxic for female rats (all rats died) after in vivo injection. Sensitivity to nephrotoxicity induced by 1,3-dichloropropene in vitro was about double in male than female rats. Reduced glutathione conjugation appeared involved in nephrotoxicity induced in males but in females, probably by means of a chloropropyl-cysteinylglycine-conjugate formation; slight toxicity in females is likely related to oxidative metabolism.