Androgen Receptor in the Ovary of Postnatal Bank Vole Females

In this experiment, we investigated the influence of the photoperiod upon androgen receptor (AR) distribution and steroid concentrations in ovaries of 21-day-old bank vole females. Sections (6 μm) were assayed immunohisto-chemically. ARs were localized in the nuclei of granulosa cells. The strongest immunoreaction was observed in primary and early antral follicles, and declined during follicular development. P 4 , A, and E 2 contents were measured by RIAs in ovarian homogenates from animals kept in two photoperiods. Ovaries of animals kept in a long photoperiod (18:6 light:dark), which stimulates gonadal activity, contained more P 4 than those kept in a short one (6:18 light:dark). There was no difference in levels of A and E 2 .