Influence of the Adrenal Glands on the Contractility of the Spleen

Abstract

The purpose of the experiments was to determine the regulatory mechanism responsible for splenic contraction and dilatation. Tournade and Chabrol 1 believe in a combined nervous and hormonal control of the splenic contractions and Izquierdo and Cannon 2 observed no erythrocytosis after exposure to low oxygen tension in an animal in which the medullary substance of the adrenal glands had been destroyed.

In 20 normal dogs under chloralose narcosis, the hematocrit curve ol the peripheral blood was studied after the injection of adrenalin, after short asphyxia and after bleeding. The dogs were then adrenalectomized (2 stage operation) and on 11 of the animals which survived adrenalectomy for more than 2 days, the same tests were repeated and the results compared. It was found that the hematocrit curves after adrenalin injection show no or only a slight decrease in their maximal elevation after adrenalectomy. In contrast to this, the hematocrit values after brief asphyxia and after bleeding did not show the elevation found in normal dogs. In Fig. 1 the curves of hematocrit determinations of an adrenalectomized dog after adrenalin injection and after short asphyxia are shown. Fig. 2 records hematocrit curves obtained after bleeding of adrenalectomized and normal dogs.

The results seem to point to the assumption that adrenalin is the significant factor responsible for splenic contraction and the resulting erythrocytosis. As it is possible that the polycythemia and the change in the size of the red blood cells after adrenalectomy may be factors which influence the hematocrit curves, one of us is repeating the experiments and studying the contraction of the spleen of adrenalectomized animals in vivo by skiagraphic visualization methods.