Inhibition of release of dopamine- -hydroxylase and norepinephrine from sympathetic nerves by colchicine, vinblastine, or cytochalasin-B (hypogastric nerve stimulation-exocytosis-microtubules-microfilaments-guinea pig).
Stimulation of the hypogastric nerve to the guinea pig vas deferens in the presence of phenoxybenzamine produced an enhanced release of both dopamine-beta-hydroxylase (EC 1.14.2.1) and norepinephrine. Addition of colchicine, vinblastine, or cytochalasin-B to the incubation medium caused an almost complete inhibition of release of both the amine and the enzyme. Colchicine and cytochalasin-B produced a blocking effect but did not, however, modify the ratio of dopamine-beta-hydroxylase to norepinephrine recovered in the bath fluid. The findings indicate that norepinephrine and dopamine-beta-hydroxylase are released from sympathetic nerve terminals by exocytosis and that this process is dependent upon the integrity of both microtubules and microfilaments.
D000818:Animals; D003078:Colchicine / Q000494:pharmacology*; D004299:Dopamine beta-Hydroxylase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006168:Guinea Pigs; D007001:Hypogastric Plexus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008870:Microtubules / Q000187:drug effects; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009183:Mycotoxins / Q000494:pharmacology*; D009433:Neural Inhibition; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010643:Phenoxybenzamine / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects; D014649:Vas Deferens / Q000187:drug effects / Q000294:innervation; D014747:Vinblastine / Q000494:pharmacology*
D009183:Mycotoxins; D010643:Phenoxybenzamine; D014747:Vinblastine; D006899:Mixed Function Oxygenases; D004299:Dopamine beta-Hydroxylase; D003078:Colchicine; D009638:Norepinephrine