The Effect of Digoxin on Rat Contractile Proteins

Ischemia reperfusion dysfunction changes model-estimated kinetics of myofilament interaction due to inotropic drugs in isolated hearts

“…Digoxin is a clinically used Na + /K + ATPase inhibitor that may regulate the formation of actinomyosin cross-bridges [ 12 ], but its effects on Ca 2+ affinity for TnCA have yet to be completely quantified. Our model parameters suggested that digoxin did not alter myofilament Ca 2+ sensitivity or cross-bridge kinetics before ischemia.…”

“…Several investigators have reported an increase in cross-bridge formation by post-synaptic adrenoceptor agonists [ 9 , 10 ], but others have failed to confirm these findings [ 11 ]. Digoxin may regulate formation of cross-bridges [ 12 ] but its effect on Ca 2+ affinity for troponin C is unclear. However, another Na + /K + ATPase inhibitor, ouabain, was shown to increase cross-bridge kinetics and myofilament Ca 2+ cycling in ventricular myocardium from patients with heart failure [ 13 ].…”