Pharmacological evidence for the presence of a beta-adrenoceptor-like agonist in the amphinoid polychaete Eurythoe complanata.
1. Methanolic extracts from the body wall of Eurythoe complanata (ExEc) were tested for biological activity on the isolated rat ileum. 2. ExEc produced either relaxation or relaxation followed by contraction of the rat ileum in a concentration-dependent manner. 3. The predominant relaxation response to ExEc was completely blocked by the beta-adrenoceptor antagonist propranolol and was unaffected by the alpha-adrenoceptor antagonist phenoxybenzamine. 4. The results indicate that the relaxation induced by ExEc is mediated by beta-adrenoceptors. The presence of a myorelaxing substance in E. complanata that selectively activates the beta-adrenoceptors is suggested.
Suadicani
S O
SO
Departamento de Fisiologia Geral, Instituto de Biociências, Universidade de São Paulo, Brazil.
de Freitas
J C
JC
Sawaya
M I
MI
D000318:Adrenergic beta-Agonists / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002854:Chromatography, Paper; D003956:Dialysis; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011077:Polychaeta / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D014020:Tissue Extracts / Q000737:chemistry / Q000494:pharmacology*
D000318:Adrenergic beta-Agonists; D014020:Tissue Extracts