Abstract
1. The effects of adrenaline on the isolated frog's heart at 27° C are not antagonized by phentolamine (1·5 × 10-6M) but are abolished at 7° C.
2. At 27° C isoprenaline was more potent than noradrenaline, but at 7° C noradrenaline was more potent than isoprenaline.
3. Phenoxybenzamine (1·5 × 10-5M) or dibenamine (1·5 × 10-5M) at 7° C abolished the work output induced by adrenaline. When the temperature was raised to 24° C, adrenaline caused an increase in work output.
4. It is concluded that in the isolated frog heart there are at least two pools of adrenoceptors, the availability of which can be governed by temperature.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Berger J. E., Mokler C. M. The interaction of quinidine with alpha and beta adrenergic receptors in the rat myocardium. J Pharmacol Exp Ther. 1969 Feb;165(2):242–250. [PubMed] [Google Scholar]
- Govier W. C., Mosal N. C., Whittington P., Broom A. H. Myocardial alpha and beta adrenergic receptors as demonstrated by atrial functional refractory-period changes. J Pharmacol Exp Ther. 1966 Nov;154(2):255–263. [PubMed] [Google Scholar]
- Kunos G., Szentivanyi M. Evidence favouring the existence of a single adrenergic receptor. Nature. 1968 Mar 16;217(5133):1077–1078. doi: 10.1038/2171077a0. [DOI] [PubMed] [Google Scholar]
- NAYLER W. G., WRIGHT J. E. EFFECT OF EPINEPHRINE ON THE MECHANICAL AND PHOSPHORYLASE ACTIVITY OF NORMO- AND HYPOTHERMIC HEARTS. Circ Res. 1963 Sep;13:199–206. doi: 10.1161/01.res.13.3.199. [DOI] [PubMed] [Google Scholar]
- Price J. M., Swann J., Nayler W. G. Effect of isoproterenol on contractions and phosphorylase activity of normo- and hypothermic cardiac muscle. Arch Int Pharmacodyn Ther. 1967 Aug;168(2):296–303. [PubMed] [Google Scholar]
- Strubelt O. Der Einfluss der Schilddrüsenfunktion auf die pharmakologischen Wirkungen von Propranolol, Adrenalin, Noradrenalin und Dinitrophenol. Arch Int Pharmacodyn Ther. 1968 Dec;176(2):263–288. [PubMed] [Google Scholar]
- Wenzel D. G., Su J. L. Interactions between sympathomimetic amines and blocking agents on the rat ventricle strip. Arch Int Pharmacodyn Ther. 1966 Apr;160(2):379–389. [PubMed] [Google Scholar]