Summary
In isolated electrically driven right auricular strips of human hearts (1 Hz at 37°C) the ability of the endogenous catecholamines noradrenaline, adrenaline, and dopamine to mediate positive inotropic effects by stimulation of myocardial α-adrenoceptors was investigated.
-
1.
The concentration-response curve for the positive inotropic effect of noradrenaline was shifted to the right by pindolol, 10−8M, whereas the additional blockade by phentolamine, 3×10−6M, was without further effect; therefore, the positive inotropic effect of noradrenaline is mediated by β-adrenoceptors only.
-
2.
In contrast, the positive inotropic effects of adrenaline as well as of dopamine are caused by stimulation of both, β- and α-adrenoceptors.
-
3.
These results are discussed with respect to the possible physiological and pathophysiological function of myocardial α-adrenoceptors.
This is a preview of subscription content, log in via an institution to check access.
References
Endoh, M., Schümann, H.J., Krappitz, N., Hillen, B.: α-adrenoceptors mediating positive inotropic effects on the ventricular myocardium: some aspects of structure-activity relationship of sympathomimetic amines. Jpn. J. Pharmacol. 26, 179–190 (1976)
Goldberg, L.J.: Cardiovascular and renal actions of dopamine: Potential clinical applications. Pharmacol. Rev. 24, 1–29 (1972)
Mary-Rabine, L., Hordorf, A.J., Bowman, F.O., Malm, J.R., Rosen, M.R.: Alpha- and beta adrenergic effects on human atrial specialized conducting fibres. Circulation 57, 84–90 (1978)
Schümann, H.J., Endoh, M., Wagner, J.: Positive inotropic effects of phenylephrine in the isolated rabbit papillary muscle mediated both by α- and β-adrenoceptors. Naunyn-Schmiedeberg's Arch. Pharmacol. 284, 133–148 (1974)
Schümann, H.J., Motomura, S., Endoh, M., Brodde, O.-E.: Comparison of the mechanism underlying the positive inotropic actions of dopamine, adrenaline, and isoprenaline on the isolated rabbit papillary muscle. Naunyn-Schmiedeberg's Arch. Pharmacol. 297, 257–267 (1977)
Schümann, H.J., Wagner, J., Knorr, A., Reidemeister, J. Chr., Sadony, V., Schramm, G.: Demonstration in human atrial preparations of α-adrenoceptors mediating positive inotropic effects. Naunyn-Schmiedeberg's Arch. Pharmacol. 302, 333–336 (1978)
Wagner, J., Brodde, O.-E.: On the presence and distribution of α-adrenoceptors in the heart of various mammalian species. Naunyn-Schmiedeberg's Arch. Pharmacol. 302, 239–254 (1978)
Wagner, J., Rodrigues-Pereira, E., Schümann, H.J.: Alpha-Adrenozeptoren im Ventrikelmyokard der Katze. Verh. Dtsch. Ges. Kreislaufforschg. 41, 226–229 (1975)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wagner, J., Schümann, H.J., Knorr, A. et al. Stimulation by adrenaline and dopamine but not by noradrenaline of myocardial α-adrenoceptors mediating positive inotropic effects in human atrial preparations. Naunyn-Schmiedeberg's Arch. Pharmacol. 312, 99–102 (1980). https://doi.org/10.1007/BF00502581
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00502581