Comparison of the Actions of Acebutolol, Practolol and Propranolol on Calcium Transport by Heart Microsomes and Mitochondria
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1 The effects of acebutolol, practolol and propranolol (0,5-3 mM) on calcium uptake, calcium binding and ATPase activities of the rabbit and rat heart microsomal and mitochondrial fractions were investigated. 2 Dose-response and time course experiments revealed that propranolol greatly inhibited microsomal and mitochondrial calcium uptake whereas both acebutolol and practolol showed slight depressant effects. 3 The ATPase activities of microsomal and mitochondrial fractions were decreased by acebutolol, practolol and propranolol; however, the latter agent was more effective than the other two. 4 The inhibitory effects of acebutolol, practolol and propranolol on mitochondria and microsomes were not antagonized by adrenaline. 5 Propranolol decreased calcium binding by the microsomal fraction only, whereas acebutolol and practolol had no effect on microsomal or mitochondrial calcium binding. 6 The sensitivity of the rabbit heart subcellular fractions to the beta-adrenoceptor blocking drugs was similar to that of the rat heart; however, the calcium uptake and ATPase activities of microsomes were more sensitive to propranolol than mitochondria in both species. 7 Perfusion of rat hearts with 0.2-1 mM propranolol decreased contractile force, and microsomal and mitochondrial fractions obtained from these hearts accummulated less calcium in comparison to the control. On the other hand, acebutolol and practolol (0.2-1nM) had no appreciable effects on contractile force or subcellular fractions under similar conditions. 8 The negative inotropic effect of propranolol may partly be due to its inhibitory actions on calcium transport by subcellular organelles of the myocardium; the depressant action of propranolol on calcium transport is unlikely to be due to its beta-adrenoceptor blocking property.
Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure.
Perez D Int J Mol Sci. 2021; 22(11).
PMID: 34071350 PMC: 8198887. DOI: 10.3390/ijms22115783.
Alterations in the heart sarcolemmal Ca2+ transport activity by some beta-adrenergic antagonists.
Dzurba A, Ganguly P, Guerin A, Dhalla N Basic Res Cardiol. 1984; 79(6):620-6.
PMID: 6152393 DOI: 10.1007/BF01908380.
Kaumann A, BLINKS J Naunyn Schmiedebergs Arch Pharmacol. 1980; 311(3):205-18.
PMID: 6104791 DOI: 10.1007/BF00569401.
Su J, Malencik D Naunyn Schmiedebergs Arch Pharmacol. 1985; 331(2-3):194-201.
PMID: 4088321 DOI: 10.1007/BF00634238.
Interaction of some antiarrhythmic drugs with the heart sarcolemmal Na+-Ca2+ exchange system.
Eyolfson D, Dhalla N Basic Res Cardiol. 1989; 84(4):414-20.
PMID: 2818441 DOI: 10.1007/BF02650876.