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Effects of ranatensin, a polypeptide from frog skin, on isolated smooth muscle
Author(s) -
CLINESCHMIDT B. V.,
GELLER R. G.,
GOVIER W. C.,
PISANO J. J.,
TANIMURA T.
Publication year - 1971
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.1476-5381.1971.tb07070.x
Subject(s) - atropine , contraction (grammar) , neuromuscular transmission , endocrinology , bradykinin , eledoisin , medicine , muscle contraction , bretylium , ileum , chemistry , phrenic nerve , duodenum , uterus , guinea pig , biology , adrenergic , receptor , neuropeptide , substance p , respiratory system
Summary1 The actions of bretylium tosylate on neuromuscular transmission in the rat phrenic nerve diaphragm preparation have been investigated by electro‐ 2 On the guinea‐pig ileum, threshold doses elicit repeated maximal spike contractions which are blocked by atropine. In the presence of atropine, higher concentrations of ranatensin elicit small contraction spikes superimposed on a relatively weak sustained contraction. These latter two actions are not blocked by increasing the concentration of atropine. 3 Other smooth muscle preparations respond as follows: rat uterus, rhythmic contractions; rat duodenum, relaxation; rabbit aortic strip, contraction. Atropine has no effect on the above responses. The rat aortic strip does not respond to ranatensin. Ranatensin is four times as active as bradykinin on the rat uterus. 4 Ranatensin can be readily distinguished from other known peptides such as angiotensin, bradykinin and the eledoisin‐like peptides, by bioassay.