Peptide TSKY Decelerates Outcome of the Ground Squirrel from Hibernation

Effect of peptide TSKY on the heart rate was studied in the ground squirrel Citellus undulatusat outcome from hibernation. At provocation of awakening in the first half of the hibernation bout (the 3rd–4th hibernation days), an intraperitoneal peptide injection at a dose of 1 mg/kg produced a deceleration of the HR increase and elongated the time of transfer of the animal to the normothermia state. This effect was not observed in the second half of the hibernation bout (the 5th–7th hibernation days). The study of the peptide cardiotropic activity on an isolated frog heart did not reveal any statistically significant TSKY activity.