[Effect of the immunostimulator tuftsin on the heart rate and body temperature of albino rats].

Tetrapeptide tuftsin (0.3 mg/kg) affected the heart rate and body temperature depending on basal physiological parameters: when administered in the state of low heart rate tuftsin produced positive chronotropic effect, whereas at higher basal heart rate the bradycardiac response was observed. Tuftsin caused biphasic changes of the body temperature: transient hyperthermia in 5 min. after peptide injection with subsequent longer period of hypothermia followed by restoration of basal level. No effect of tuftsin occurred after reserpine injection. At the same time tuftsin potentiated the hypothermia induced by reserpine. The time course and sign of vegetative effects of tuftsin correlate with some of its behavioural effects.