Effects of (+/-)-, (+)- and (-)-celiprolol on the rat left atria and portal vein.
Differing effects of (+/-)-celiprolol at beta-adrenoceptors have been reported. The effects of (+/-)-, (+)- and (-)-celiprolol on the contractile responses of the rat left atria and portal vein have therefore been studied. (+/-)-Celiprolol did not augment the responses of the atria to electrical stimulation and is therefore not an agonist at beta 1-adrenoceptors. Prolonged treatment with (+/-)-celiprolol attenuated the contractile activity of the vein and this effect was blocked by ICI 118,551 and is therefore mediated by agonism at beta 2-adrenoceptors. The pA2 values for (+/-)-, (+)- and (-)-celiprolol at the beta 1-adrenoceptors of the atria were 8.0, 6.0 and 8.6, respectively. On the protal vein, (+/-)- and (-)-celiprolol produced non-parallel rightward shifts of log isoprenaline attenuation curves with a reduction in isoprenaline maximum responses. This effect of (+/-)-celiprolol on the vein was not due to slowly reversible antagonism, as the inhibitory effect of (+/-)-celiprolol was readily reversible.
Doggrell
S A
SA
Department of Pharmacology, School of Medicine, University of Auckland, New Zealand.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D017272:Celiprolol; D004558:Electric Stimulation; D006325:Heart Atria / Q000187:drug effects*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011169:Portal Vein / Q000187:drug effects*; D011412:Propanolamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C026777:ICI 118551; D017272:Celiprolol; D007545:Isoproterenol