Methoxychlor-Induced Atresia: DISCUSSION(4)


Regarding the effect of MXC on hormonal parameters, MXC-induced atresia did not result in changes in estradiol, FSH, or LH, hormones known to be important antiapoptotic factors in follicles. In spite of the decline in antral follicles that we observed in mice treated with MXC, we did not see a difference in estradiol levels between the sesame oil- and MXC-treated mice. This was initially surprising because antral follicles are a major producer of estradiol, but there may be several explanations for this finding. canadian neighbor pharmacy

First, the reduction in antral follicles that we observed with MXC treatment may not be dramatic enough to alter endogenous estradiol levels. Second, it is possible that the remaining follicles compensate for the loss of follicles by increasing their estradiol production, (i.e., the few remaining antral follicles are producing high levels of estradiol to compensate for follicular loss). Finally, it is possible that MXC increases estrogen production by nonovarian tissues, such as fat.

Regarding the gonadotropins, previous studies examining the effect of MXC in male rats found that serum levels of LH were unaffected by 200-400 mg kg-1 day-1 MXC treatment for 44 wk. On the other hand, Okazaki et al. observed a decline in LH and FSH levels in male rats treated for 28-31 days with 100 or 500 mg/kg MXC, respectively. Also, the investigators observed a decline in LH levels in female rats treated with 100 or 500 mg/kg MXC for 2831 days.