[Non-adrenergic mechanisms of inhibition of the contractile activity of the cat small intestine by histamine, bradykinin, and met-enkephalin].
I. a. histamine and bradykinin caused both an activation and an inhibition of jejunal contractile activity. The inhibitory effect was preserved after blockade of muscarinic cholinoreceptors, alpha- and beta-adrenoceptors, and abolished with the nicotinic cholinoceptor blockade. Metenkephalin inhibited the jejunal contractile activity after first activating it. The inhibitory effect of the peptide was preserved after blockade of alpha- and beta-adrenoceptors as well as the nicotinic cholinoceptors. The data obtained suggest that the non-adrenergic inhibitory effect of metenkephalin on intestinal contractions was the result of its depressing action on motor cholinergic neurons, whereas the inhibition of intestinal contractile activity with histamine and bradykinin resulted from their activating action on cholinergic interneurons which activate non-adrenergic inhibitory neurons through nicotinic cholinoceptors.
Institute of Experimental Medicine, Russian Acad. Med. Sci, 197376, St. Petersburg, Acad. I. P. Pavlov St., 12.
V I
VI
Ovsiannikov
T P
TP
Berezina
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002415:Cats; D003864:Depression, Chemical; D004744:Enkephalin, Methionine / Q000494:pharmacology*; D006632:Histamine / Q000494:pharmacology*; D007583:Jejunum / Q000187:drug effects* / Q000502:physiology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D018733:Nicotinic Antagonists / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D004744:Enkephalin, Methionine; D006632:Histamine; D001920:Bradykinin