Methoxychlor-Induced Atresia: RESULTS(3)


Effect of MXC on the Ovaries of Mice That Overexpress Bcl-2 Protein

In wild-type mice, MXC (64 mg kg-1 day-1 for 20 days) significantly increased the percentage of atretic follicles compared with controls (Fig. 4). Wild-type mice treated with MXC had 59% atretic follicles, whereas wild-type mice treated with sesame oil had 43% atretic follicles (Fig. 4A; n = 8; P < 0.03). In Bcl-2 overexpressing mice, MXC was unable to significantly increase the percentage of atretic follicles compared with the sesame oil-treated Bcl-2 overexpressing mice. MXC-treated Bcl-2 overexpressing mice had 48% atretic follicles and sesame oil-treated Bcl-2 overexpressing mice had 50% atretic follicles (Fig. 4A; n = 7; P = 0.7).

In addition, levels of atresia in MXC-treated Bcl-2 overexpressing mice were no different than the levels in sesame oil-treated wild-type mice (48% vs. 43%; Fig. 4A; n = 7-8; P = 0.4).

MXC-treated Bcl-2 overexpressing mice had significantly more antral follicles (1726 ± 155) than MXC-treated wild-type mice (1330 ± 99; n = 7-9; P < 0.05), and of these, the number of healthy antral follicles in the Bcl-2 overexpressing mice was greater than those of the MXC-treated wild-type mice (903 ± 123 vs. 540 ± 72, respectively; Fig. 4B; n = 7-9; P < 0.03).
Fig4Methoxychlor-Induced Atresia-4
FIG. 4. Effect of MXC on atresia and antral follicle numbers in Bcl-2-overexpressing mice. A) The effect of MXC on antral follicle atresia. Bars represent means ± SEM, and bars with different letters are significantly different from each other (n = 7-9; P s 0.03 for a vs. b). B) The effect of MXC on the total number of antral follicles and healthy antral follicles in MXC-treated wild-type mice vs. MXC-treated Bcl-2-overexpressing mice (n = 7-8; P s 0.05) and the number of healthy follicles in sesame oil-treated wild type mice vs. MXC-treated wild-type mice (n = 7-8; P s 0.04). Bars, Means ± SEM; *significant difference.