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The role of prostacyclin in modulating cholinergic neurotransmission in guinea‐pig ileum
Author(s) -
Gaion R.M.,
Trento M.
Publication year - 1983
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.1476-5381.1983.tb10031.x
Subject(s) - hexamethonium , physostigmine , tetrodotoxin , endocrinology , medicine , acetylcholine , prostacyclin , cholinergic , atropine , ileum , chemistry , stimulation , isometric exercise , guinea pig , biology
1 The mechanism of action of prostacyclin (PGI 2 ) on isolated segments of guinea‐pig terminal ileum was studied by recording the changes in isometric tension. 2 In these preparations PGI 2 (1 n m ‐1 μ m ) caused a concentration‐dependent increase in muscle tension. This effect was rapid and short‐lasting. 3 PGI 2 ‐induced contractions were inhibited by atropine and potentiated by physostigmine. 4 Hemicholinium‐3 reduced the response to PGI 2 and the inhibition was quantitatively comparable at any PGI 2 concentration tested. 5 Tetrodotoxin as well as low temperature (20°C) abolished and β‐bungarotoxin reduced the effect of PGI 2 . 6 Hexamethonium decreased the response to submaximal, but not to maximal PGI 2 concentrations. 7 PGI 2 potentiated the twitch response of the ileum to electrical stimulation. 8 In the presence of tetrodotoxin, PGI 2 did not alter the effect of a sub‐maximal concentration of acetylcholine (ACh). 9 The present results give indirect evidence for the ability of PGI 2 to facilitate ACh release from intramural nerves possibly by increasing the excitability of cholinergic cell bodies.