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. 1981 Jun;73(2):355–362. doi: 10.1111/j.1476-5381.1981.tb10429.x

Pre- and postjunctional effects of clonidine-and oxymetazoline-like compounds in guinea-pig ileal preparations

E Malta, C Raper, Pauline E Tawa
PMCID: PMC2071678  PMID: 7236990

Abstract

1 Noradrenaline and 28 imidazolidine (clonidine-like) and imidazoline (oxymetazoline-like) compounds with various phenyl ring substituents have been examined for their ability to inhibit responses to transmural stimulation and exogenous acetylcholine in ileal preparations from reserpine-treated guinea-pigs.

2 The bathing solution contained propranolol, mepyramine, cimetidine and desipramine to preclude interference with the responses by other than the α-receptor-mediated actions of the compounds.

3 In transmurally stimulated preparations the inhibitory response to noradrenaline is due to a combination of prejunctional α-adrenoceptor stimulation and a postjunctional depressant effect that does not involve adrenoceptor activation.

4 Of the 28 imidazolidines and imidazolines studied, 21 inhibited transmurally elicited responses. In the various compounds studied this effect involved actions at pre- or postjunctional sites as indicated by (a) the frequency-dependence of the inhibitory response, (b) its susceptibility to blockade by α-receptor antagonists and (c) the relative concentrations required to inhibit responses to transmural stimulation and exogenous acetylcholine.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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