[The role of delta sleep-inducing peptide in the electric stability of the heart].

An experimental study in 38 rabbits explored the effect of delta-sleep peptide and its deficiency on thresholds of ventricular fibrillation or its precursors. The delta-sleep peptide (60 nM/kg) was shown to increase electric stability of the heart by elevating the thresholds of ventricular fibrillation and its precursors (ventricular extrasystoles and paroxysmal ventricular tachysystoles). Systemic deficiency of this peptide (the administration of antiserum T = 1:2000--1:3000, at 1:60 dilution) was, on the contrary, associated with lower ventricular arrhythmia thresholds. Therefore, delta-sleep peptide is shown to possess antiarrhythmic activity which may account for its protective cardiac effect under emotional stress.