Influence of a Pyrimidopyrimidine Derivative on Deamination of Adenosine by Blood

Abstract

The disappearance of exogenous adenosine from blood is principally due to its degradation into inosine and hypoxanthine by the enzymes present in the erythrocytes. In the presence of intact red cells, Persantin (RA-8 or 2,6-Bis (diethanolamino) -4,8-dipiperidinopyrimido-(5,4-d)-pyrimidine) effectively prevents the disappearance of adenosine. Although Persantin inhibits adenosine deaminase its adenosine-sparing action in whole blood is more likely due to a reduction in permeability of the red cell membrane to adenosine. This property of Persantin makes possible its use as a tool in investigation of the role of adenine nucleotide derivatives in the regulation of the coronary circulation.