OBJECTIVETo investigate the effects of carbaryl on serum steroid hormone and function of antioxidant system in female Sprague Dawley rats.

METHODSCarbaryl was administrated to the adult female rats at doses of 0, 1.028, 5.140 and 25.704 mg x kg(-1) x d(-1) for 30 d. Vaginal smears of rats were taken to determine estrous cycle. Serum 17beta-estradiol (E(2)) and progesterone (P(4)) concentrations were measured by radioimmunoassay. The activities of superoxide dismutase (SOD) and glutathione-s-transferase (GST), and the levels of malondialdehyde (MDA) and glutathione (GSH) were measured by spectrophotometry.

RESULTSThe number of estrous cycle in exposed groups were obviously lower than in control group (P < 0.05, P < 0.01). Body weight gain in high dose group (25.704 mg x kg(-1) x d(-1)) was significantly lower than that in control. Meanwhile, the organ coefficient of ovary and uterus declined in a dose-dependent manner. Serum E(2) level [(19.93 +/- 2.21) nmol/L] in 25.704 mg group was lower than in control group [(28.76 +/- 6.12) nmol/L, P < 0.05], and P(4) level (1.21 +/- 0.40) nmol/L in 1.028 mg group was higher than that in control group [(0.63 +/- 0.39) nmol/L, P < 0.05]. The activity of SOD first reduced then rose in ovary, and first rose then reduced in serum. The contents of MDA increased in ovary, while decreased in the serum. GSH contents and GST activity increased in ovary, while in serum GSH contents decreased and GST activity first increased then decreased.

CONCLUSIONCarbaryl could disrupt estrous cycle and affect serum steroid hormone, and the function of antioxidant system in female SD rats.