THE INACTIVATION OF ADENOSINE BY BLOOD, WITH SPECIAL REFERENCE TO CAT'S BLOOD

¹ The Departments of Pathology and Biochemistry, University of Cambridge

1. There is present in cat's plasma an enzyme system which is capable of inactivating adenosine.

2. The inactivation is accompanied by the liberation of ammonia, and it is probable that it is due to the deamination of adenosine and the production of inosine, which is biologically inactive.

3. The capacity of the plasma to inactivate adenosine is considerably increased under certain experimental conditions. The reason for this change is not understood.

4. The plasma from other animals also contains a similar enzyme, but it is present in much smaller quantity.

5. Whole blood from different animals inactivates adenosine at different rates. This apparently depends more upon the different amount of enzyme which is present in the blood-cells than that in the plasma.

6. Muscle adenylic acid and adenyl pyrophosphoric acid are also inactivated by plasma, but very much less readily than adenosine.