IMMUNOHISTOCHEMICAL ANALYSIS OF ANDROGEN RECEPTOR IN THE ABDOMINAL GLANDS OF THE CLOACA OF MALE RED-BELLIED NEWTS, CYNOPS-PYRRHOGASTER

Androgen receptor immunoreactivity was examined in the abdominal gland s of the cloaca in adult male red-bellied newts, Cynops pyrrhogaster, using a polyclonal anti-androgen receptor antibody, PG21. In castrated males treated with saline, prolactin, testosterone propionate or both prolactin and testosterone propionate, all displayed androgen recepto r immunostaining of nuclei in the epithelial cells of the glands. Andr ogen receptor-immunoreactive signals were distributed uniformly in the nuclei in the castrates treated with saline or prolactin. On the othe r hand, the signals were distributed reticulately in the nuclei in the castrates treated with testosterone propionate or both prolactin and testosterone propionate. Following treatment with testosterone propion ate or both prolactin and testosterone propionate, shape of the androg en receptor-immunoreactive nuclei was altered from nonspherical profil es toward spherical profiles and its size became increased. There were no differences in these changes between the testosterone propionate- and both prolactin and testosterone propionate-treated castrates. Thes e findings suggest that androgen participates in regulating size and s hape of the nuclei and distribution of androgen receptor in the nuclei of the epithelial cells of the abdominal glands of male newts and tha t the structural reorganization is necessary for gene expression under the influence of androgen.