Morphological changes in the rabbit ovary after active immunization to testosterone

The role of testosterone in follicular development was investigated by immunizing female rabbits (mean wt 1.4 kg) to testosterone-3-bovine serum albumin (T-3-BSA). Controls received BSA. Follicular diameters and histology, and ovarian and uterine weights were recorded at intervals up to 11 weeks. At 5 weeks T-3-BSA ovaries did not differ from controls in either histology or follicular diameter (number of follicles ≥1.0 mm were 12.5±3.4 and 17.0±1.0 for BSA and T-3-BSA treated animals respectively). By 8 weeks T-3-BSA animals had multiple cystic and hemorrhagic follicles. T-3-BSA ovaries contained more follicles ≥1.0< 1.5 mm (27.3±3.1 vs. 15.3±2.9, P<0.01) and ≥1.5 mm diameter (5.8±1.7 vs. 0.4±0.3, P<0.005). At 11 weeks T-3-BSA ovaries contained more follicles > 1.5 mm in diameter (5.0±0.9 vs. 0.9±0.3, p< 0.001). Increased vascularization, some thecal hypertrophy and marked interstitial cell hypertrophy were characteristic of the T-3-BSA ovaries at 8 and 11 weeks. These results suggest that testosterone has a role in the regulation of follicular development.