The steroidogenic capacity of the LCs was not significantly affected in either unstimulated or hCG-stimulated prepubertal testis parenchyma from control and EDS exposed male offspring on PND 24, although there were trends toward increases in T production under both unstimulated and hCG-stimulated conditions (Fig. 3). Likewise, there was a trend toward increased unstimulated T production on PND 82. However, in these adults hCG-stimulated T production was more than doubled, 2.4 ± 0.2 vs. 8.4 ± 2.0 mg/mg testis in control and EDS-treated mice, respectively.
Although hCG-stimulated T production was increased in adult testis parenchyma ex vivo, serum T was unaffected. Serum LH was not affected by EDS treatment at the prepubertal time point. In adult EDS-exposed mice, despite the unchanged serum T levels, serum LH levels were increased 4-fold, 0.46 ± 0.09 vs. 2.10 ± 0.67 ng/ml for control and EDS-exposed mice, respectively (Fig. 4).
Light microscopic examination of the neonatal (PND 1) testes from EDS-exposed mice revealed a seminiferous epithelium containing primarily Sertoli cells with only a limited organization of germ cells (Fig. 5). There was an abundance of LCs in the interstitium of both vehicle-treated and EDS exposed testis; however, the LCs tended to form aggregates of greater than 20 LCs in testes of EDS-exposed males. The testes of prepubertal (PND 24) control males revealed a maturing seminiferous epithelium with the presence of a lumen and evidence of active spermatogenesis. By contrast, the testes of the EDS-exposed prepubertal mice primarily contained Sertoli cells with abundant cytoplasm but few germ cells. Testes from adult (PND 82) control males revealed complete spermatogenesis.
FIG. 3. Treatment-related changes in ex vivo T production by testis parenchyma. A) T production (ng/mg of testis) of both vehicle and eDS-exposed prepubertal (PND 24) CD-1 mouse testes incubated with or without maximal hCG-stimulation for 2 h. Note a trend toward increases in T production. Values represent litter means ± SEM; N = 7 and 8 for vehicle and EDS-exposed groups, respectively. B) T production (^g/mg of testis) of both vehicle and EDS-exposed adult (PND 82) CD-1 mouse testes incubated with or without maximal hCG-stimulation for 2 h. Values represent litter means ± SEM; statistical significance (P < 0.01 = *) is indicated; N = 9 and 6 for vehicle- and EDS-exposed groups, respectively.
FIG. 4. Effect of EDS exposure on serum T (A) and LH (B) levels in the prepubertal (PND 24) and adult (PND 82) male mouse. Values represent litter means ± SEM; statistical significance (P < 0.05 = *); N = at least 5 in each group.