Dihydrotestosterone (DHT) binding studies and the effects of DHT on the expression of beta-glucuronidase (Gus) and kidney androgen-regulated protein (KAP) genes and cell growth were investigated in immortalized early PKSV-PCT and late PKSV-PR proximal tubule cells, derived from transgenic mice carrying the L-pyruvate kinase/SV40 hybrid gene. [3H]DHT binding studies indicated that both cell lines have conserved substantial amounts of androgen receptors. The levels of KAP and Gus transcripts in PKSV-PCT cells, and those of KAP transcripts in PKSV-PR cells, decreased when cells were shifted from a serum-supplemented to a steroid-free medium. The addition of 30 nM DHT to the steroid-free medium resulted in a slight increase in Gus and in a more marked increase in KAP transcripts in both cell lines. Dihydrotestosterone also affected the growth of PKSV-PCT and PKSV-PR cells, since this hormone added to the steroid-free medium stimulated the incorporation of [3H]thymidine in a dose-dependent manner and induced the formation of domes, which represent indicators of ionic transport processes. Thus, because these early and late mouse proximal tubule cells have conserved androgen receptors, they represent attractive cell systems to analyze the action of androgens on specific functions of the mouse proximal tubule.