In vivo, testosterone-treatment of female hamsters for 4 days promotes a doubling of α2-adrenoreceptor protein in parametrial adipocytes, with a concomitant accumulation of the α2A-adrenoreceptor subtype mRNA. During in vitro incubation of minced parametrial fat pads for 6 to 48h with testosterone or dihydrotestosterone (100 nM), α2A-adrenoreceptor protein and mRNA levels were also increased and remained to control levels when an antiandrogen or actinomycin D were added in the medium. It is concluded that in hamster adipocytes, androgens upregulate α2A-adrenoreceptor subtype expression at the mRNA level by an androgen receptor-dependent transcriptional activation.