title: Action of propranolol on mitochondrial proton fluxes.
abstract: The action of propranolol, a Beta-blocking adrenergic agent, on mitochondrial proton fluxes in nonenergized and energized conditions has been studied. 1. The drug inhibited the actions of valinomycin, higericin and FCCP on the inner mitochondrial membrane. 2. It decreased the rate and extent of active energized proton expulsion and passive collapse of the proton gradient so formed. 3. Propranolol was able to increase the permeation of chloride ion through the inner mitochondrial membrane in nonenergized and energized conditions. 4. The drug inhibited mitochondrial contraction but stimulated swelling in various conditions. It is suggested that propranolol is is able to change the proton and chloride permeabilities of mitochondria by perturbing the structure of inner membrane phospholipids, thus enlarging the water-lipid interface.
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism; D066298:In Vitro Techniques; D008928:Mitochondria / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D008933:Mitochondrial Swelling / Q000187:drug effects; D009550:Nigericin / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology*; D011522:Protons; D051381:Rats; D013997:Time Factors; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D002712:Chlorides; D011522:Protons; D014634:Valinomycin; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D011433:Propranolol; D009550:Nigericin