Cation transport by gastric H+:K+ ATPase.
A vesicular microsomal fraction isolated from hog fundic mucosa demonstrates the capacity to take up equal amounts of RB+ and Cl-. The amount of the Rb+ uptake is sensitive to the extravesicular osmolarity, and rate of uptake is sensitive to temperature. 86Rb+ efflux is dependent upon the cation composition of the diluting solution. ATP, but not beta-gamma methylene ATP, induces a reversible efflux of 86Rb+ from loaded vesicles, and this is dependent upon a functional K+-ATPase. The ATP induced efflux is not affected by CCCP (carbonyl cyanide m-chlorophenylhydrazone) or TCS (tetrachlorosalicylanilide) nor by lipid soluble ions or valinomycin. Nigericin inhibits the efflux by 40%. Uptake of the lipid soluble ion 14C-SCN- has been demonstrated and is enhanced by ATP only in the presence of valinomycin. The results are consistent with a neutral or isopotential exchange of H+ for Rb+ mediated by K+-ATPase.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D004789:Enzyme Activation; D005753:Gastric Mucosa / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008566:Membranes / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism*; D009708:Nucleotidases / Q000378:metabolism; D009994:Osmolar Concentration; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D012413:Rubidium / Q000378:metabolism; D013552:Swine; D013861:Thiocyanates / Q000378:metabolism
D013861:Thiocyanates; D009708:Nucleotidases; D000251:Adenosine Triphosphatases; D008274:Magnesium; D012413:Rubidium; D011188:Potassium