Effects of ouabain on sodium uptake by frog heart and skeletal muscle.
Effects of ouabain (10(-3)-10(-12) M) on frog heart and skeletal muscle net uptake of Na from a K-free Conway-Ringer solution at 0-2 degrees C were investigated. Under these circumstances Na pumps are inactive and fibers are gaining Na even without ouabain. Changes in K, H2O, and solids were also measured. Na gains and K losses were increased by ouabain at greater than 10(-6) and greater than 10(-7) M, respectively, and decreased in heart muscle at less than or equal to 10(-8) M. It is suggested that these effects are due to actions on membrane permeability. Implications for mechanisms of positive inotropic effect of glycosides and for treatment are discussed.
D000818:Animals; D001001:Anura; D001692:Biological Transport / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects; D006333:Heart Failure / Q000378:metabolism; D066298:In Vitro Techniques; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology*; D010539:Permeability; D011188:Potassium / Q000378:metabolism; D011896:Rana temporaria; D012964:Sodium / Q000378:metabolism*
D010042:Ouabain; D012964:Sodium; D011188:Potassium