title: Steroid-induced inhibition of nucleoside uptake in isolated mouse thymocytes.
abstract: In view of the evidence suggesting a possible effect of high concentrations of steroids on membrane properties, we have investigated the effect of several steroid molecules on the uptake and incorporation of [3H]uridine is isolated mouse thymocytes. Our results demonstrate that the sex steroids, the estrogenic compound, diethylstilbestrol, and several non-hormonal steroid molecules induce a marked inhibition of nucleoside uptake. This effect, which occurs only at concentrations above 10(-6) M, is almost instantaneous but transient and does not therefore appear to be mediated through specific receptor occupancy. Since sex steroids have been shown to inhibit mitogen-induced blast transformation at concentrations close to 10(-5) M, we suggest that this membrane effect of sex steroids may partly explain their immunosuppressive effects.
mesh_terms: D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D004054:Diethylstilbestrol / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D007700:Kinetics; D051379:Mice; D011277:Pregnanediones / Q000494:pharmacology; D013256:Steroids / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000378:metabolism*; D013739:Testosterone / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism*; D014529:Uridine / Q000378:metabolism*
chemical_list: D011277:Pregnanediones; D013256:Steroids; D013739:Testosterone; D004054:Diethylstilbestrol; D003907:Dexamethasone; C006477:alphaxalone; D013936:Thymidine; D014529:Uridine