Effect of depolarizing concentrations of potassium on calcium uptake and metabolism in rat liver.
Exposure of perfused livers of fed rats to 60 mM K+ induces rapid responses in the Ca2+-sensitive metabolic events, glycogenolysis, cytoplasmic and mitochondrial NADH/NAD ratios and octanoate oxidation. All increase within 45 s of K+ addition. Metabolic responses were not observed following K+ addition to livers perfused in the absence of added Ca2+. Movements of Ca2+ into the liver were suggested from experiments in which 45Ca2+ uptake was measured. The Ca2+ antagonists verapamil, diltiazem and Ni2+ essentially abolished changes to tissue metabolism and Ca2+ fluxes induced by K+ addition. K+-induced changes were consistent with Ca2+ channel activation.
D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002210:Caprylates / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004110:Diltiazem / Q000494:pharmacology; D006003:Glycogen / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology
D002210:Caprylates; D009243:NAD; D006003:Glycogen; D014700:Verapamil; D004110:Diltiazem; C031492:octanoic acid; D011188:Potassium; D002118:Calcium