Pharmacological experiments demonstrate that toad (Bufo marinus) atrial beta-adrenoceptors are not identical with mammalian beta2- or beta1-adrenoceptors

O'Donnel S.R. and Wanstall J.C. (1982) Pharmacological experiments demonstrate that toad (Bufo marinus) atrial beta-adrenoceptors are not identical with mammalian beta2- or beta1-adrenoceptors. Life Sciences, 31 7: 701-708. doi:10.1016/0024-3205(82)90772-X


Author O'Donnel S.R.
Wanstall J.C.
Title Pharmacological experiments demonstrate that toad (Bufo marinus) atrial beta-adrenoceptors are not identical with mammalian beta2- or beta1-adrenoceptors
Journal name Life Sciences   Check publisher's open access policy
ISSN 0024-3205
Publication date 1982-08-16
Sub-type Article (original research)
DOI 10.1016/0024-3205(82)90772-X
Open Access Status Not yet assessed
Volume 31
Issue 7
Start page 701
End page 708
Total pages 8
Subject 3004 Pharmacology
Abstract Chronotropic responses to symphathomimetic amines of isolated atrial preparations from toads (Bufo marinus) were mediated by β-adrenoceptors since isoprenaline was more potent than adrenaline and noradrenaline, and propranolol was a potent antagonist (pA2, adrenaline as agonist = 9.33). The β-adrenoceptors had some of the characteristics of mammalian β2-adrenoceptors in that (i) adrenaline was more potent than noradrenaline and (ii) the pA2 values of two selective β-adrenoceptor antagonists, atenolol (pA2 = 5.84) and α-methylpropranolol (pA2 = 8.42), were close to the values reported on β2-adrenoceptors in mammalian tissues. However, the relative potencies of adrenaline, isoprenaline, noradrenaline, rimiterol, salbutamol and fenoterol (1 : 45.8 : 0.07 : 3.3 : 1.05 : 0.32) did not correspond to the relative potencies reported for these agonist on mammalian tissues which contain predominantly β2-adrenoceptors. Also the pA2 value for the β2-selective antagonist, ICI 118,551 (7.89, adrenaline as agonist) was lower than its reported pA2 on β2-adrenoceptors in mammalian tissues. There was no evidence that the response was mediated by both β1-andβ2-adrenoceptors since Schild plots for ICI 118,551 using three agonists of differing selectivity (adrenaline, rimiterol and noradrenaline) weer superimposed. It is concluded that, although toad atrial β-adrenoceptors have several characteristics in common with β2-adrenoceptors in mammalian tissues, these amphibian β-adrenoceptors are not identical with mammalian β2-adrenoceptors.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import - Archived
 
Versions
Version Filter Type
Citation counts: Scopus Citation Count Cited 6 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 28 Jun 2016, 14:58:01 EST by System User