Sugar and oxygen relationships in the blood of dogs

Abstract

Before subjecting the organism to certain experimental conditions capable of changing the sugar and oxygen relationships of dog's blood, it was thought advisable to determine the variations and relationships which might normally be encountered within the same individual at different times and in different individuals.

The blood sugar was estimated by the MacLean method. The capacity of the blood for oxygen and its actual oxygen content were determined by the Van Slyke technic. Specimens of blood from the external jugular veins of resting dogs were drawn by aspiration without exposure to the air, at intervals of one and one half or two hours over periods of six, or seven and one half hours. To date eleven such series of observations on eight dogs have been completed.

In view of the frequent statement in the literature that even a slight amount of hemorrhage may induce hyperglycemia and because loss of corpuscles would tend to reduce the oxygen-carrying capacity of the blood, the effects of loss of blood on the factors to be studied were examined. The total amount of blood in the body was assumed to be five per cent. of the body weight.

Successive samples were drawn until about ten per cent. of the total amount in the body had been removed before the final sample was taken. Although there were individual instances in which the blood sugar rose slightly above its initial value, it was usually found to progressively decrease. A slight but unmistakable decrease in the oxygen content and capacity of the blood was found following hemorrhage of this extent. Compare columns I1 and 111, VI and VII, X and XI of Table I.

Although the actual amounts of the blood sugar, oxygen content and capacity may vary somewhat when studied at different times in one individual, the average level assumed by each of these factors seems to be characteristic for the individual.