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Receptors for neurotransmitters in opossum oesophagus muscularis mucosa
Author(s) -
Daniel E.E.,
Jury J.,
Robotham K.H.
Publication year - 1986
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.1476-5381.1986.tb10254.x
Subject(s) - muscarinic acetylcholine receptor , carbachol , endocrinology , medicine , muscularis mucosae , receptor , muscarinic acetylcholine receptor m2 , atropine , acetylcholine , muscarinic acetylcholine receptor m4 , biology , muscarinic acetylcholine receptor m3 , chemistry , stimulation
1 Muscularis mucosa of the distal oesophagus of the opossum contains nerves which release acetylcholine and substance P(SP)‐like material on field stimulation. The release of SP‐like material appeared to be inhibited by the presence of exogenous muscarinic agonists and potentiated by muscarinic antagonists. Analysis of the postjunctional receptors involved using carbachol, McNeil A‐343 (McN A‐343), atropine and pirenzipine suggested that the receptors were not typical M 2 ‐muscarinic receptors. The potency of agonists and antagonists were consistent with some receptor properties resembling M 1 ‐muscarinic receptors. 2 Prejunctional receptors to opiates, adenosine, agonists at α 2 ‐adrenoceptors and prostaglandins were not detected. 3 Receptors for tachykinins were present on the muscle in this tissue, but did not resemble clearly either SP‐E or SP‐P type receptors. They appear to be undifferentiated since most tachykinins were of similar potency. 4 These results suggest that not all postjunctional muscarinic receptors in intestinal smooth muscle are M 2 in type. There may be a gradation of types between M 1 and M 2 .