Summary
-
1.
Responses to phenylephrine of left and right atria of the rat heart have been measured at 37°C and 21°C.
-
2.
Differences in basal force of contraction at the two temperatures were attributable solely to differences in frequencies of contraction.
-
3.
Reduction in temperature produced no change in EC50 for phenylephrine nor any greater susceptibility of the responses to blockade by phentolamine rather than propranolol.
-
4.
It is concluded that β-adrenoceptors of the rat heart are not converted to α-adrenoceptors by a reduction in temperature.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Benfey, B. G.: Temperature dependence of phenoxybenzamine effects and the adrenoceptor hypothesis. Nature 256, 745–747 (1975)
Benfey, B. G.: Temperature, phenoxybenzamine and adrenoceptor transformation. Nature 259, 252 (1976)
Daly, J. W., Creveling, C. R., Witkop, B.: The chemorelease of norepinephrine from mouse hearts. Structure-activity relationships. I. Sympathomimetic and related amines. J. Med. Chem. 9, 273–380 (1966)
Freedberg, A. S., Hamolsky, M. W.: Effects of thyroid hormones on certain nonendocrine organ systems. In: Handbook of Physiology, Vol. III, Section 7, pp. 435–468 (Greer, M. A., Solomon, D. H., eds.). Washington: American Physiological Society 1974
Iversen, L. L.: The uptake and storage of noradrenaline in sympathic nerves. Cambridge: University Press 1967
Kunos, G.: Thyroid hormone-dependent interconversion of myocardial α-and β-adrenoceptors in the rat. Br. J. Pharmacol. 59, 177–190 (1977)
Kunos, G., Nickerson, M.: Temperature-induced interconversion of α-and β-adrenoceptors in the frog heart. J. Physiol. (Lond.) 256, 23–40 (1976)
Kunos, G., Nickerson, M.: Effects of sympathetic innervation and temperature on the properties of rat heart adrenoceptors. Br. J. Pharmacol. 59, 603–614 (1977)
Kunos, G., Mucci, L., Jaeger, V.: Interconversion of myocardial adrenoceptors: its relationship to adenylate cyclase activation. Life Sci. 19, 1597–1602 (1976)
Ledda, F., Marchetti, P., Mugelli, A.: Studies on the positive inotropic effect of phenylephrine: a comparison with isoprenaline. Br. J. Pharmacol 54, 83–90 (1975)
Parr, J. J., Urquilla, P. R.: Analysis of adrenergic receptors of pacemaker and myocardial cells. Eur. J. Pharmacol. 17, 1–7 (1972)
Starke, K.: Alpha sympathomimetic inhibition of adrenergic and cholinergic transmission in the rabbit heart. Naunyn-Schmiedeberg's Arch. Pharmacol. 274, 18–45 (1972)
Wagner, J., Reinhardt, D.: Characterization of the adrenoreceptors mediating the positive ino-and chronotropic effect of phenylephrine on isolated atria from guinea-pigs and rabbits by means of adrenolytic drugs. Naunyn-Schmiedeberg's Arch. Pharmacol. 282, 295–306 (1974)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bennett, T., Kemp, P.A. Lack of evidence for a temperature-mediated change of adrenoceptor type in the rat heart. Naunyn-Schmiedeberg's Arch. Pharmacol. 301, 217–222 (1978). https://doi.org/10.1007/BF00507040
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00507040