Longitudinal Distribution of Blood in the Rabbit in Relation to the Heart, with Observations on the Contribution of Different Organs

Abstract

The distribution of blood along the length of an animal is relevant to the stability of cardiac filling pressure during tilting. We investigated the longitudinal distribution of blood in conscious, anesthetized, and dead, rabbits by a scanning technique, after labeling red blood cells with 51 Cr. The mean longitudinal distributions of blood were computed after standardization for body size and radioactivity. The longitudinal distribution of blood showed a large main peak near the level of the tricuspid valve. General anesthesia produced very little change in blood distribution, but after death blood left the lower abdomen and accumulated in the upper abdomen, probably in the liver. The liver made much the greatest contribution (25 to 30%) to the total pool of blood, but the blood contained within it was labile and could be largely removed by bleeding the animal, or transferred to the lungs during pulmonary congestion.