A study of metabolic effects of experimental polycythemia in dogs

Abstract

Although the clinical and morphological signs of plethora vera are known to a large extent, the metabolic effects produced by increasing the amount of blood in the body have been but sparingly investigated. The present research deals with the latter question. The augmentation of the supply of blood was effected by intravenous transfusion of defibrinated blood taken from the same species. In one experiment direct transfusion was performed after connecting a femoral artery of one dog with a small branch of a saphenous vein in another. After each transfusion, as will be shown later, there developed a condition of the blood that closely resembled polycythemia, as observed in man. These experiments also bear upon certain phases of the general question of parenteral nutrition.

Seven experiments were conducted on as many apparently healthy dogs that were kept under observation for some time before the experiments were started. The majority of the experiments lasted from 5 to 6 weeks. Some dogs were under observation for even a longer time. Each experiment was divided into preliminary periods of normal nutritional conditions, and subsequent periods during which the metabolic influences of blood transfusion were studied. Two animals were put through a period of fasting that lasted 16 days in one case and 25 days in the other, during each of which two blood transfusions were performed to ascertain their possible nutritive value and metabolic effects. In some cases the effect of the ether narcosis was determined as was also the influence on metabolism of the operation itself without the transfusion. The body weight, the amount, specific gravity, and reaction of the urine, and the weight of the dried feces were noted in the daily record.