SUPPLEMENTARY EFFECT OF a-TOCOPHEROL SUCCINATE (VITAMIN E) ON SODIUM ARSENITE-INDUCED OVARIAN STEROIDOGENIC FUNCTION AND PLASMA LEVELS OF GONADOTROPHINS IN MATURE ALBINO RATS

Abstract

Ovarian, uterine, vaginal weights, and ovarian steroidogenic enzyme activities, along with plasma levels of gonadotrophins and estrogen, were measured in diestrous phase of mature Wistar-strain albino rats following subchronic treatment with Na-arsenite at the dose available in drinking water found in wide areas of West Bengal in India. A signiŽcant reduction in plasma levels of LH, FSH, and estradiol, with signiŽcant diminution in the activities of 15-3 ̄ , 17 ̄-HSD followed by a low level of ovarian and uterine peroxidase activity, were observed in Na-arsenite–treated rats at 0.4 ppm/rat/day for 28 days (7 estrous cycles) in comparison to control. This duration of treatment also exhibited weight loss of the above-mentioned organs, with prolonged diestrous phase followed by a high accumulation of arsenic in plasma and in those organs in contrast to controls. Supplementation of ®-tocopherol succinate at 200 mg/kg body weight/rat/day for 28 days with arsenic treatment minimized the gonadal weight loss signiŽcantly and restored the activities of ovarian steroidogenic enzymes as well as ovarian and uterine peroxidase at control level. Not only that, this vitamin also elevated the plasma levels of LH, FSH, and estradiol compared with arsenic-treated rats. Vaginal smear showed normal cyclic changes of estrous in ®-tocopherol succinate supplemented arsenic-treated rats, though arsenic levels in plasma and gonadal tissue remained unaltered in comparison to arsenic-treated rats. Thus, our experiments indicate the signiŽcant protective action of ®-tocopherol succinate on the above-mentioned parameters in arsenic-treated rats.