rapid. The presence of an excess of glucose in the blood did not cause any alteration in the rate of glycolysis. Macleod offers the following conclusions: 1. Unclotted (hirudin) and defibrinated blood have the same glycolytic power, but potassium oxalate, in concentrations of one per thousand and over diminishes glycolysis. 2. The rate of glycolysis varies in specimens of defibrinated blood taken at differ ent times from the same animal; and it varies also in the blood from different animals of the same species. 3. On an average, about one-half of the original amount of dextrose disappears in heating the blood to 58°C. destroyed glycolysis completely, thus proving that glycolysis is a fermentative process. According to him the causative enzyme issues from the blood cells, as the serum does not have any glycolytic power, an observation which has been confirmed by other observers. Thus the leucocytes are supposed to have such glycolytic qualities (Lepine and Boulud) and the glycolytic quality of blood is supposed to be lessened when typical leucopenia is present (Löwy and Richter) and increased by hyperleucocytosis (M. Hahn). two and one-half hours from blood kept According to von Noorden, Jr., while outside the body at 40°C. 4. Glycolysis is a function of the corpuscles and is absent in the serum. It disIt disappears from the corpuscles after frequent washing with isotonic solution. 5. The addition of dextrose to blood does not materially increase the extent of the glycolysis occurring in a given time. In higher concentrations it may indeed depress the process. 6. The source of the dextrose, i.e., whether chemical or derived from glycolysis by the action of glycogenose, bears no relationship to the rate of glycolysis. Glycolysis proceeds at the same rate in normal as in "diabetic" blood. 7. Even under the most favorable cir cumstances the quantity of dextrose which the blood can destroy is only a small fraction of that which disappears in the same time in an intact animal. The glycolysis which occurs in blood is most probably of no importance in carbohydrate metabolism. 8. No evidence could be obtained of an increase of sugar as a result of allowing freshly drawn blood to stand at body temperature for varying periods of time up to one hour. Lepine made extensive studies of glycolysis in vitro and found that cooling the blood decreases glycolysis. He found that the optimum temperature was about 38° or 39°C., and that the blood corpuscles possess a glycolytic power, yet this can not be proved for the erythrocytes. The production of the glycolytic ferment by leucocytes depends upon their integrity. According to Doyon and Morel, if the blood is diluted with 10 times its quantity of water, no glycolysis takes place. Lepine, Rona and Doblin confirm these observations. On the other hand Edelmann found that after destroying the cellular elements of the blood by saponin (100 mgm. saponin to 50 cc. of blood) the glycolytic power of blood was not changed. He has not proved, however, that the leucocytes were dissolved by this procedure. Rona and Doblin, and von Noorden demonstrated that the glycolytic ferment which causes glycolysis in blood in vitro is present in plasma; and also Istate that there is evidence that the leucocytes contain considerably more of this enzyme than do the red blood cells. The belief that the disappearance of sugar from the blood is due to the action of a special glycolytic enzyme |