Investigations on the circulation of anesthetized dogs.

In the present experiments arterial blood pressure, cardiac output, heart rate, oxygen consumption, AVO2 difference values and their changes were investigated in 64 anesthetized dogs in four periods for altogether 60 min. Blood flows of the renal, commune carotid and femoral arteries were measured in parallel and the changes were recorded throughout the 60 min of the experimental period. Urine was collected separately from both kidneys, in order to determine whether the measurement of the blood flow of the renal artery disturbed renal functions. Total peripheral vascular resistance and the vascular resistance of the territories of the commune carotid and femoral arteries were calculated from the parameters measured. In the present experiments the equation of the regression line between cardiac output and body weight was y = 0.102x + 0.9411. The equation of the regression line between cardiac output an body surface proved to be y = 2.996x + 0.653. The relationship between total oxygen consumption and body weight could be characterized by the y = 5.815x + 24.227 equation. Our data were in accordance with data of the Biology Data Book obtained in dogs anesthetized by pentobarbital. Our present data can be found but partially in the Biology Data Book, so the results obtained in the present study may serve as basis of future comparisons. In this work proper care was taken to maintain the same conditions and, thus ruling out possible artefacts. The experiments were carried out on mongrel dogs of different sexes; nevertheless, the animals were attempted to be kept under the same conditions for the 14 days preceding the experiments.