title: Anti-microtubular agents as inhibitors of desensitization to catecholamine stimulation of adenylate cyclase in Ehrlich ascites tumor cells.
abstract: Adenylate cyclase activity of the homogenate of Ehrlich ascites tumor cells pretreated with catecholamine at 37 degrees C was not stimulated by the addition of the same catecholamine, whereas that of the cells without the pretreatment was stimulated. Such a desensitization was induced hardly at all when the pretreatment was performed at low temperature. The desensitization of adenylate cyclase activity to catecholamine stimulation was prevented by pre-pretreatment of the cells with colchicine prior to the catecholamine pretreatment. The effect of colchicine was dependent on the period of the treatment and concentration of colchicine. Vinblastine had a similar effect, whereas cytochalasin B was without effect. Thus, involvement of microtubules was suggested in the desensitization of the membrane-associated enzyme to external stimulation.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000201:enzymology*; D002395:Catecholamines / Q000494:pharmacology*; D003078:Colchicine / Q000494:pharmacology*; D003571:Cytochalasin B / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology; D051379:Mice; D008870:Microtubules / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D013696:Temperature; D014747:Vinblastine / Q000494:pharmacology
chemical_list: D002395:Catecholamines; D003571:Cytochalasin B; D014747:Vinblastine; D000262:Adenylyl Cyclases; D003078:Colchicine; D009638:Norepinephrine; D004837:Epinephrine