Incorporation of adenosine into ATP: formation of compartmentalized ATP.

Abstract

The incorporation of [3H]adenosine, [3H]adenine and [3H]hypoxanthine into adenine nucleotides of nude (athymic) mouse liver and human hepatoma grown subcutaneously in nude mice was studied. 3H and 32P radioactive labeling in vivo of acid soluble nucleotides followed by chromatographic procedures indicated that, in contrast to [3H]adenine and [3H]hypoxanthine, [3H]adenosine is preferentially incorporated into ATP in comparison with its incorporation into AMP and ADP. This phenomenon, as well as complementing the recently reported 3-fold increase in total cellular ATP on treatment with 0.5-1.0 mM concentrations of adenosine, indicates the formation from adenosine of compartmentalized ATP that is not produced from adenine or hypoxanthine. The observed effect is of larger magnitude in the growth arrested normal liver than in the actively growing tumor.