[Effect of apressin on the mechanism regulating vascular tone]

Acute experiments with anesthetized and decerebrate cats brought evidence that in a dose of 1 mg/kg apressin first increases by 50 per cent the centrogenically-produced pressor vascular reactions and then (30-60 min thereafter) suppresses pressor responses. Apressin (in a dose of 3-5 mg/kg) appreciably weakens the intensity of the pressor vascular reactions and increases the efferent outflow in the renal nerve. In doses of 1-10 mg/kg it does not affect the transmission of excitation in the superior cervical sympathic ganglion and in the solar plexus nodes. In tests with the crossed circulation apressin in doses of 1 and 5 mg/kg produces a marked depression of vascular reactions and a drop of the perfusion pressure in the vessels of the hind extremity perfused with the autoblood and a rising intensity of these reactions along with a greater resistance of the hind extremity vessels, perfused with the donor's blood.