Effect of vinblastine, a potent antimicrotubular agent on steroid secretion by perifused frog adrenal glands.
The role of microtubules in adrenal steroidogenesis was examined in vitro, using frog interrenal tissue. Adrenal dice from Rana ridibunda were perifused with amphibian culture medium and the effect of various antimicrotubular drugs was studied. The amounts of corticosterone and aldosterone released in the effluent perifusate were radioimmunoassayed using specific antisera. Administration of colchicine, nocodazole, and vinblastine (10(-5) M) did not affect spontaneous secretion of corticosterone and aldosterone. These results indicated that, in contrast to microfilaments which play an important role in spontaneous steroidogenesis, the microtubular system is not required for basal corticosteroid secretion. However, vinblastine (10(-5) M) was responsible for a marked decrease in ACTH-induced stimulation of corticosterone and aldosterone production. Conversely, vinblastine did not significantly alter the response of interrenal tissue to dibutyryl cAMP, forskolin and NaF, indicating that the microtubules are involved in an early step of ACTH action, namely at the level of the receptor subunit.
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D066298:In Vitro Techniques; D008297:Male; D008870:Microtubules / Q000187:drug effects; D010477:Perfusion; D011895:Rana ridibunda; D014747:Vinblastine / Q000494:pharmacology*
D014747:Vinblastine; D000324:Adrenocorticotropic Hormone