Autoinduction of Androgen Receptor mRNA in Primary Cultures of Hamster (Mesocricetus auratus) Harderian Gland Cells

The Harderian gland (hg) is a gland which occupies a large portion of the orbital cavity. In many species, a sexual dimorphism occurs, which suggests a gonadal steroid control of the hg. The present study examines, in primary cultures of hamster hg cells, the regulation of the androgen receptor mRNA (AR mRNA) expression. In dose–response experiments measuring the expression of AR mRNA, testosterone (T) (10 −12 M ) induced a 1-fold increase of AR mRNA compared with unexposed cells, and this effect reached its zenith (6.2-fold) when cells were exposed to 10 −8 M T. In other experiments, cells were exposed or not to different drugs [T, T + flutamide (F), F, T + cycloheximide (Cy), Cy] for different times (up to 96 hr). These experiments showed a time-dependent increase of AR mRNA in the cells exposed to T, while in the cells exposed to F, T+F, T+Cy, Cy, and control (unexposed), a time-dependent decrease of AR mRNA was observed. The size of the hamster AR mRNA in these in vitro experiments was similar to that observed in other mammals (9.5 kb). It is concluded that primary cultures of hamster hg cells are a valuable model for studying hg cell activity and that in this system T autoinduces its own receptor.