Scores of 1 +, 2 +, 3 + and 4 + were, respectively, considered for
atretic follicles with 25, 50, 75 and 100 percent positivity for lipid staining.
Oocyte developmental G1 G2 stages Primary growth 20.08 [+ or -] 3.08 34.94 [+ or -] 3.84 (*) Pre-vitellogenic 11.91 [+ or -] 2.54 13.14 [+ or -] 2.07 Vitellogenic 2.65 [+ or -] 1.58 6.01 [+ or -] 2.78 Post-ovulatory follicles 4.30 [+ or -] 1.74 10.40 [+ or -] 2.16 (*)
Atretic follicles 61.06 [+ or -] 5.24 (*) 35.50 [+ or -] 5.03 Table 5.
The presence of apoptotic bodies was observed only in
atretic follicles, which was likely due to the absence of survival factors in oocyte that induce the activation of the endogenous apoptosis pathways (Quirck et al., 2004) leading to oocyte atresia.
In our experiments, all treatment groups (EE, BPA 30, 300, and 900 ppm, and BPAF 30, 300, and 900 ppm), had significantly higher numbers of dead or
atretic follicles. With the BPA and BPAF treatment groups, the lowest doses of the toxicants had greater effects on oocyte death, with a smaller effect as the dose of EDC became higher.
Figure 2 shows the number of antral, primordial, and
atretic follicles in the ovaries of all groups.
We observed a decrease in the percentage of healthy follicles and concomitantly an increase in the percentage of
atretic follicles in the ovaries of taiep rats when compared to SD rats (Figure 7(c)).
On the other hand, group C reported higher count of
atretic follicles and corpora lutea in comparison to controls.
The number of primordial follicles, primary follicles, secondary follicles, and
atretic follicles in all the serial sections of an ovary were counted.
Sections were examined by using calibrating ocular graticule for the number and diameter of primary, antral and
atretic follicles and number and size of the ovarian cysts, by the method described earlier.14 Follicles were counted and classified according to a previously published method.15
The numbers of
atretic follicles grade I (cystic and invasive atresia) and grade II (obliterative and residual atresia) were also counted [17].
It has been suggested that these cysts arise from an abnormal response of
atretic follicles in the ovaries to circulating Beta-hCG, which may or may not be high.
Single
atretic follicles with typical histological structure were defined on the periphery of sections.
