Body Fluid Changes in Neurogenic Hypertension and Total Paravertebral Sympathectomy

Abstract

This is a report of changes which have been observed in the blood volume, plasma volume, hematocrit and red blood cell count under various conditions of vascular tension resulting from operative interference with vasomotor nerve supply. These studies have been made on normal dogs, dogs made hypertensive by resection of both carotid sinuses, both aortic depressor nerve pathways, and one or the other vagus, and dogs made hypertensive by total paravertebral sympathectomy. Two hypertensive dogs have been subjected to total paravertebral sympathectomy and 2 sympathectomized dogs to the procedure used for production of hypertension and the subsequent changes noted.

Plasma volume was measured by the use of disappearance curves of the blue dye, T-1824. Blood volume was estimated from the plasma volume and hematocrit. Blood loss encountered during each experiment was corrected by transfusion of an equal volume of blood from donor dogs.

As indicated in the accompanying graph, the following observations have been made:

First, that dogs subjected to modulator nerve section (MNS) develop marked hypertension and a markedly increased total blood volume apparently due entirely to an increase in the cellular fraction of the blood.

Second, that these hypertensive, polycythemic dogs regain approximately a normal total blood volume and their hypertension is markedly reduced after total paravertebral sympathectomy. This decrease in total blood volume after sympathectomy is apparently due to a decrease in cells alone, the plasma volume remaining unchanged.