Effect of Adrenalin and Pituitrin on the Volume of the Liver.

Abstract

In view of the contradiction which exists in the literature in regard to the effects of adrenalin and pituitrin on the circulation in the liver, we have used the liver plethysmograph, which has been previously described, 1 in a new attack on this problem. The results will be very briefly described in this preliminary report without substantiation from actual records or attempt to cite the literature; these will appear in due time.

Cats and rabbits under chloralose anesthesia have been used in this work; the results are as follows:

I. Intravenous injections of adrenalin. 1. Pressor doses invariably produce constriction in the liver, whether introduced by way of the femoral, or portal veins, or hepatic artery, provided the general blood pressure is high and the animal in good condition. This constriction may last as long as the pressor response or it may at times give way to prompt and active dilation; when this latter occurs it may be abolished by section of the depressor nerves (rabbit). On the other hand, if the animal is in poor condition with low blood pressure the liver apparently dilates passively during the pressor response to an injection by way of the femoral vein. This is intensified by first clamping the hepatic artery, but is prevented altogether and even replaced by constriction if the portal vein has been previously clamped so as to restrict the volume changes in the liver to variations in its arterial blood supply; i. e., the liver is forced to expand under these conditions and in spite of active vasoconstriction within itself, because of an engorgement through its massive portal supply. This in turn is probably due to an unusual movement of blood through the toneless (?) mesenteric capillaries as a result of the high general blood pressure.