Comparison of the β-adrenoceptors in the myocardium and coronary vasculature of the kitten heart

摘要: The relative potencies of (minus) noradrenaline, (minus)-adrenaline, (plus or minus)-isoprenaline and minus)-salbutamol have been assessed for their positive inotropic chronotropic actions on kitten isolated atria. These compared with those obtained the coronary dilator in two preparations. were intact hearts perfused by Langendorff's method arteries from kitten. molar effects noradrenaline 1: adrenaline1: iso-prenaline 7: salbutamol 0.6. observed ratios not significantly different effects. adrenaline isoprenaline as myocardial stimulants similar to dilators heart. Similar also found artery but was only one third active this preparation. In both heart about tenth noradrenaline. It therefore less a than stimulant. spite these differences potency effects, dissociation constants (Kb values) practolol against driven atria arteries. Myocardial vascular beta-adrenoceptors thus can be placed general classification beta1-adrenoceptors.