cardiovascular system
• ouabain, a glycoside poison that binds to and inhibits the sodium-potassium pump (inhibits Atp1a1 but not Atp1a2 in these mutants), increased cardiac contractility in isolated mutant hearts and resulted in greater positive inotropy than in wild-type
• 3-fold greater increase in the maximal rate of contraction and the rate of contraction at 40 mm Hg than in wild-type after ouabain infusion, however heart function and response of cardiac contraction to beta-adrenergic stimuli was normal under regular conditions (without ouabain)
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muscle
• ouabain, a glycoside poison that binds to and inhibits the sodium-potassium pump (inhibits Atp1a1 but not Atp1a2 in these mutants), increased cardiac contractility in isolated mutant hearts and resulted in greater positive inotropy than in wild-type
• 3-fold greater increase in the maximal rate of contraction and the rate of contraction at 40 mm Hg than in wild-type after ouabain infusion, however heart function and response of cardiac contraction to beta-adrenergic stimuli was normal under regular conditions (without ouabain)
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