ジエチルスチルベステロールに曝露した受精卵に由来するニホンウズラの精巣及び精巣上体の構造とアンドロジェン受容体の局在 Structures and Androgen Receptor Localization in the Testes and Epididymis of Japanese Quail Hatched from the Eggs Exposed to Diethylstilbestrol

The present study was undertaken to determine whether exposure of fertile eggs to an estrogenic chemical (diethylstilbestrol, DES) affects the structures of the testes and epididymis in matured Japanese quail. Fertile eggs were separated into 3 groups and immersed in test solutions prepared by dissolving DES in 95 % ethanol at concentrations of 0, 5 mg or 50 mg/100 ml (Groups C, L and H, respectively). The birds were sacrificed 100 days after hatching, and their testes, epididymis and cloacal glands were examined by histology and immunocytochemistry for androgen receptors. The structure of the seminiferous tubules in Group C birds was well organized with numerous sperm attached to the epithelium. Although the structure of seminiferous tubules in Group L did not show significant differences from those of Group C, the epithelium of the seminiferous tubules was thinner and the population of sperm attached to the epithelium was greatly reduced in Group H. The epididymis of Group C birds was well developed, consisting of the rete testis, proximal and distal efferent ductules and epididymal duct. In birds hatched from DES treated eggs, the epididymis was less well developed and had fewer tubules compared with Group C. However, immunoreactive androgen receptors were found in the epithelial cells of tubules in the epididymis of Groups C, L and H. The sizes of the cloacal glands were significantly smaller in Groups L and H when compared with Group C. These results suggest that DES exposure of fertile eggs causes structural and functional disruption of testes and epididymis, which may be one of the significant endpoints for endocrine disruptive effects in birds.