Electrical and molecular coupling between sodium and proton fluxes in basolateral membrane vesicles of rat liver.
Mechanisms of Na+-H+ exchange in the hepatocyte were studied utilizing isolated basolateral membrane vesicles prepared by two different methods: Evidence was obtained for the existence of molecular coupling of Na+ and H+ fluxes (Na+/H+-antiport) which exhibits saturation kinetics (Km 7 mmol/l Na+) and is inhibited by amiloride (1.0 mmol/l). Although the two membrane preparations showed differences with respect to ionic permeabilities, our data suggest that a relatively high H+ conductance exists in the basolateral plasma membrane. Hence, electrical coupling of conductive H+ and Na+ fluxes in the opposite direction could contribute to net Na+-H+ exchange across the basolateral hepatocyte plasma membrane.
D000818:Animals; D001692:Biological Transport; D004563:Electrochemistry; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism; D009994:Osmolar Concentration; D011188:Potassium / Q000378:metabolism; D011522:Protons; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D012979:Sodium Radioisotopes
D011522:Protons; D012979:Sodium Radioisotopes; D006859:Hydrogen; D012964:Sodium; D011188:Potassium