Heterogenic contractile response of rat left ventricular myocytes to beta1-adrenoceptor stimulation.
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.
Stones
Rachel
R
School of Biomedical Sciences, University of Leeds, Worsley Building, Leeds, West Yorkshire, LS2 9JT, UK.
Billeter
Rudolf
R
Harrison
Simon
S
White
Ed
E
D058665:Adrenergic beta-1 Receptor Agonists; D058671:Adrenergic beta-1 Receptor Antagonists; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001262:Atenolol / Q000494:pharmacology; D048430:Cell Shape / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D016014:Linear Models; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011412:Propanolamines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018342:Receptors, Adrenergic, beta-1 / Q000502:physiology*; D016276:Ventricular Function
D058665:Adrenergic beta-1 Receptor Agonists; D058671:Adrenergic beta-1 Receptor Antagonists; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D018342:Receptors, Adrenergic, beta-1; C026777:ICI 118551; D001262:Atenolol; D007545:Isoproterenol