Immunohistochemical localization of androgen receptor in two subpopulations of porcine granulosa cells in vitro

In the ovarian follicles of mammals, androgens are utilized as substrates for estrogen synthesis or can act via androgen receptor (AR). Within the ovary, granulosa cells generally display the strongest immunoreactivity for AR protein. Therefore, the aim of the present study was to analyse possible changes in the intensity of AR staining in cultured mural and antral granulosa cells isolated from follicles at various stages of development. Porcine ovaries were obtained at a local slaughterhouse and the follicles were classified as small, medium and large dependently on their diameter. Isolated granulosa cells were separated into two populations, mural and antral, and then the cells were cultured during 48 h. After this time the cells were fixed and immunostained to visualize the AR. Androgen receptor immunostaining was detected in both, antral and mural granulosa cell cultures isolated from follicles at all stages of the development. In the mural granulosa cultures the immunostaining was comparatively weaker than that in the antral granulosa cells originating from all types of follicles. Our results provide immunohistochemical evidence that antral granulosa layer is the main site of AR immunoexpression.