[Coupling of insulin-stimulated ATP formation by preparations of plasma membrane-enriched particles with proton transport across the plasma membranes of target cells].

In the particles enriched with plasmatic membranes of target cells (human erythrocytes, skeletal muscles and adipocytes of rats) ATP was steadily formed within 1 min of incubation of the particles with insulin (4 microgram/ml) in the medium containing Tris-HCl buffer, pH 7.5, ADP, Mg2+, inorganic phosphate, NaF, during NADH oxidation in presence of cytochrome c and oxygen (30 degrees). Introduction of proton ionophore p-trifluoromethoxycarbonyl cyanide phenylhydrazone (pFCCP) into the incubation medium before addition of human erythrocyte particles enriched with plasmatic membranes and of insulin led to a distinct increase of the insulin-stimulated accumulation of ATP in erythrocyte plasmatic membranes: at 10(-6) M concentration of pFCCP the increase was 3.5-fold, at 5 X 10(-6) M of pFCCP it was even 8-fold. In presence of 10(-4) M pFCCP the insulin-stimulated ATP accumulation was increased 2-fold in the particles from rat adipocytes. Output of protons into the medium and its acidification (alteration of pM by 0.01-0.012) within 3-6 sec was found in experiments with impulse administration of insulin 100 micrograms and pFCCP 0.1 micrograms into the suspension of freshly isolated rat adipocytes (5 ml) added to an electrolyte containing 150 mM NaCl, 10 mM beta-hydroxybutyric acid, 0.01 mM Gly-Gly (pH 7.45).