[Phrenic blood flow in cats with closed abdominal cavity]

By means of ultrasonic method, used in acute experiments on cats with closed abdominal cavity under nembutal narcosis, the authors studied the linear and volumetric blood flow velocity in left phrenic artery, the resistance of vascular bed of the phrenic artery, systemic blood pressure, respiration excursions during asphyxia, hypoxia, infusion of some biologically active substances. It was shown, that shortening of the diaphragm has definite influence on the blood flow and resistance of the vascular bed of the phrenic artery; the degree of the decrease of the blood flow in inspiration (on relation to the value of the blood flow in expiration, that passed as 100%) does not differ significantly in quiet and intensive respiration. Under the influences, the resistance of vascular bed of the phrenic artery decreases, the linear and volumetric blood flow increases, that indicates large reserve of the vascular bed of the phrenic artery for the increase of the blood flow.