[The mechanism of action of thyrocalcitonin on myocardial cells].

Thyrocalcitonin preserved its effect on the electric and contractile activity of the myocardial cells even under the influence of 2,4-dinitrophenol. Administration of the hormone during a considerable drop in amplitude and duration of the action potential due to DNP effect led to increase in the amplitude and to a still greater decrease in duration of the action potential. The contraction amplitude reduced by DNP was also augmented by the hormone administration.