IMMUNOHISTOCHEMICAL LOCALIZATION AND IMMUNOBLOTTING OF ANDROGEN RECEPTOR IN SPINAL NEURONS OF MALE AND FEMALE RATS

Androgen activity in the central nervous system, as in other tissues, is mediated by the androgen receptor. We performed the precise localiz ation of the androgen receptor in spinal cord of male and female adult rats by immunohistochemistry using polyclonal antibodies. Light micro scopy indicated immunoreactivity in the anterior horn with a strong st aining in motoneurons, but staining was also observed in the posterior horn. Electron microscopy showed a predominant nuclear immunostaining . A weaker but significant immunoreactive androgen receptor was also n oted in the perinuclear/intracysternal position. Moreover, no differen ces were found between male and female rats. Immuno-blotting demonstra ted that the androgen receptor is expressed in both ventral and dorsal spinal cord, with an apparent molecular mass identical to that noted in other androgen-dependent tissues. The expression of androgen recept or in motoneurons corroborates the role of androgens in motoneuron gro wth, development and regeneration and underlies the possibility that a ndrogen receptor abnormality leads to the motoneuron degeneration obse rved in X-linked spinal and bulbar muscular atrophy.