AUTOINDUCTION OF ANDROGEN RECEPTOR MESSENGER-RNA 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 exami nes, in primary cultures of hamster hg cells, the regulation of the an drogen receptor mRNA (AR mRNA) expression. In dose-response experiment s measuring the expression of AR mRNA, testosterone (T) (10(-12) M) in duced 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 1 0(-8) M T. In other experiments, cells were exposed or not to differen t drugs [T, T + flutamide (F), F, T + cycloheximide (Cy), Cy] for diff erent times (up to 96 hr). These experiments showed a time-dependent i ncrease of AR mRNA in the tells exposed to T, while in the cells expos ed 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 t hese in vitro experiments was similar to that observed in other mammal s (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 sy stem T autoinduces its own receptor. (C) 1996 Academic Press, Inc.