Reduction of androgen receptor mRNA concentration by testosterone in mouse submandibular gland

In this study, we examine the effect of testosterone on the steady-state concentration of androgen receptor (AR) mRNA of mouse submandibular gland. Northern blot analysis showed the expression of an AR-specific 10-kb transcript in the submandibular glands of both sexes. Quantitative analysis was done by means of reverse transcription-polymerase chain reaction (RT-PCR) with a non-radioactive label of digoxigenin. The RT-PCR demonstrated that the steady-state of AR mRNA concentration was less in males than in females. Moreover, AR mRNA increased in the castrated male mice, while the administration of testosterone reduced the AR mRNA in female mice. In conclusion, the amount of AR mRNA in mouse submandibular gland is reduced by androgen.