Effect of propranolol and related drugs on transmembraneous pH differences in liposomes.

Propranolol (1-isopropylamino-3-(1-naphtoloxy)-propan-2-ol) a beta-adrenergic receptor blocking agent was found to cause changes of transmembraneous pH in liposomes prepared from Soy-lecithin and cardiolipin. When the external pH was neutral and the internum of the liposomes acidic, the drug decreased the pH gradient. When the externum was acidic and the internum neutral, the gradient was increased by the drug. The effect of butacaine was similar to that of propranolol, while procaine, timolol and practolol were ineffective. It is suggested that the charged form of propranolol is bound to the membrane and dislocates protons from binding sites in the membrane and that the uncharged form of propranolol penetrates the membrane. After penetration it could associate with protons in the intraliposomal compartment and hence increase the pH of the interior. Depending on the direction of the pre-existing proton gradient propranolol would thus be able to increase or decrease the pH difference across the liposomal membrane.

[1]  S. Orrenius,et al.  The inhibition of the mitochondrial NADH oxidase by alprenolol and the protective effect of cytochrome P-450. , 2009, Acta pharmacologica et toxicologica.

[2]  J. Järvisalo,et al.  Action of propranolol on mitochondrial functions--effects on energized ion fluxes in the presence of valinomycin. , 1975, Biochemical pharmacology.

[3]  J. Järvisalo,et al.  Action of propranolol on mitochondrial functions--effects on non-energized ion fluxes. , 1975, Biochemical pharmacology.

[4]  J. Järvisalo Change of mitochondrial buffering capacity induced by propranolol , 1975, Journal of bioenergetics.

[5]  Järvisalo Jo Action of propranolol on mitochondrial proton fluxes. , 1975 .

[6]  G. Gardos,et al.  Mechanism of various drug effects on the Ca2+‐dependent K+‐efflux from human red blood cells , 1974, FEBS letters.

[7]  I. Smith,et al.  The effects of local anesthetics on lipid multilayers. A spin probe study. , 1973, Archives of biochemistry and biophysics.

[8]  T. Narahashi,et al.  Mechanism of action of propranolol on squid axon membranes. , 1973, The Journal of pharmacology and experimental therapeutics.

[9]  P. Seeman,et al.  The membrane actions of anesthetics and tranquilizers. , 1972, Pharmacological reviews.

[10]  D. Papahadjopoulos Studies on the mechanism of action of local anesthetics with phospholipid model membranes. , 1972, Biochimica et biophysica acta.

[11]  H. Andersen,et al.  Thermogenesis of brown adipose tissue reflected in mitochondrial respiratory control. , 1970, Acta physiologica Scandinavica.

[12]  D. Papahadjopoulos,et al.  Studies on model membranes. I. Effects of Ca2+ and antibiotics on permeability of cardiolipin liquid-crystalline vesicles. , 1970, Biochimica et biophysica acta.

[13]  V. Manninen Movements of sodium and potassium ions and their tracers in propranolol-treated red cells and diaphragm muscle. , 1970, Acta physiologica Scandinavica. Supplementum.

[14]  E. Williams Mode of action of beta receptor antagonists on cardiac muscle. , 1966, The American journal of cardiology.

[15]  B. Prichard,et al.  Use of propranolol in conjunction with alpha receptor blocking drugs in pheochromocytoma. , 1966, The American journal of cardiology.

[16]  J. Skou,et al.  Local anaesthetics. VI. Relation between blocking potency and penetration of a monomolecular layer of lipoids from nerves. , 2009, Acta pharmacologica et toxicologica.