Role of adrenergic mechanisms in cardiac and respiratory effects of digoxin.

The respiratory and cardiac effects of digoxin the the dog were both markedly reduced by ganglionic blockade and reserpinization, but only the cardiac effects were significantly modified by propranolol. This gives support to our previous hypothesis that digoxin cardiac effects depend, in part, on extra-cardiac mechanisms and its relationship with respiratory effects results from the fact that both effects are dependent directly and reflexly from sympathetic nervous activation.