Nandrolone treatment decreases the alpha1B-adrenoceptor mRNA level in rat kidney, but not the density of alpha1B-adrenoceptors in cultured MDCK-D1 kidney cells.

We have previously shown that treatment of rats with the anabolic androgen steroid nandrolone decreased the density of alpha1B-adrenoceptors in the rat kidney [Uhlén, S., Lindblom, J., Kindlundh, A., Muhisha, P., Nyberg, F., (2003). Nandrolone treatment decreases the level of rat kidney alpha1B-adrenoceptors. Naunyn-Schmiedeberg's Arch. Pharmacol. 368, 91-98]. This effect may have been caused either by decreased de novo synthesis of alpha1B-adrenoceptors or by increased degradation of alpha1B-adrenoceptors [corrected] In the present study, we show that treatment of rats with nandrolone decreases the level of mRNA for the alpha1B-adrenoceptor in the kidneys, implying decreased synthesis of alpha1B-adrenoceptors. On the other hand, nandrolone did not decrease the density of alpha1B-adrenoceptors in Madin-Darby Canine Kidney (MDCK) cells, even though the sub-cell line tested, MDCK-D1, expresses both the androgen receptor and the alpha1B-adrenoceptor. It is concluded that the regulation of alpha1B-adrenoceptor expression by anabolic androgenic steroids is intricate and cell-type specific.