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EXCITATORY EFFECT OF A NEW POLYPEPTIDE (ANTHOPLEURIN‐B) FROM SEA ANEMONE ON THE GUINEA‐PIG VAS DEFERENS
Author(s) -
NORTON T.R.,
OHIZUMI Y.,
SHIBATA S.
Publication year - 1981
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1981.tb09951.x
Subject(s) - vas deferens , phentolamine , guanethidine , medicine , endocrinology , verapamil , tetrodotoxin , reserpine , sea anemone , chemistry , apamin , propranolol , biology , stimulation , potassium channel , calcium , ecology
1 Anthopleurin‐B (AP‐B, > 3 × 10 −9 m), a newly isolated polypeptide from sea anemone ( Anthopleura xanthogrammica) , caused powerful rhythmic contractions in the guinea‐pig isolated vas deferens. The other polypeptides anthopleurin‐A from A. xanthogrammica and anthopleurin‐C from A. elegantissima , elicited similar effects but in higher concentrations (> 5 × 10 −8 m). Toxin II (10 −6 m) isolated from the sea anemone, Anemonia sulcata , had no effect 2 The rhythmic contractions induced by AP‐B were inhibited by phentolamine, bretylium, guanethidine, reserpine, 6‐hydroxydopamine, tetrodotoxin (TTX) and verapamil. Mecamylamine, atropine, methysergide, chlorpheniramine, and indomethacin had no effect 3 AP‐B (10 −8 m ∼10 −5 m) caused a dose‐dependent increase in the amount of endogenous noradrenaline (NA) released from the vas deferens. AP‐B (10 −5 m) increased the amount of NA released to approximately 310 times (12 μ/g tissue) that of untreated tissues 4 The AP‐B‐induced release of N A was inhibited or abolished by TTX, verapamil, or incubation in Ca‐free medium 5 These results suggest that the AP‐B‐induced rhythmic contraction of the vas deferens is mediated through the release of NA from adrenergic nerve endings; AP‐B is one of the most potent substances in stimulating NA release from the vas deferens.