Abstract
We measured the contractile response of left ventricular cardiac myocytes from female rats to selective beta(1)-adrenoceptor stimulation (isoprenaline, 10(-8) M and 10(-7) M in the presence of 10(-7) M ICI 118,551 a beta2-adrenoceptor inverse agonist). A heterogenic response to stimulation, inversely related to the extent of cell shortening prior to adrenergic stimulation, was observed. Challenge of cardiac myocytes with a selective beta1-antagonist, atenolol (10(-7) M), suggests the heterogenic response is not caused by basal beta1-adrenoceptor activity. Thus, basal myocyte contractility determines the response to beta1-adrenoceptor stimulation, this should be taken into account when experimental conditions are designed.
Publication types
-
Comparative Study
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adrenergic beta-1 Receptor Agonists
-
Adrenergic beta-1 Receptor Antagonists
-
Adrenergic beta-Agonists / pharmacology
-
Adrenergic beta-Antagonists / pharmacology
-
Animals
-
Atenolol / pharmacology
-
Cell Shape / drug effects
-
Dose-Response Relationship, Drug
-
Drug Synergism
-
Female
-
Heart Ventricles / cytology
-
Heart Ventricles / drug effects
-
Isoproterenol / pharmacology
-
Linear Models
-
Myocytes, Cardiac / cytology
-
Myocytes, Cardiac / drug effects
-
Myocytes, Cardiac / physiology*
-
Propanolamines / pharmacology
-
Rats
-
Rats, Sprague-Dawley
-
Receptors, Adrenergic, beta-1 / physiology*
-
Ventricular Function*
Substances
-
Adrenergic beta-1 Receptor Agonists
-
Adrenergic beta-1 Receptor Antagonists
-
Adrenergic beta-Agonists
-
Adrenergic beta-Antagonists
-
Propanolamines
-
Receptors, Adrenergic, beta-1
-
ICI 118551
-
Atenolol
-
Isoproterenol