Incorporation of Adenosine and Adenosine Triphosphate into Rat Myocardium

Abstract

The isolated rat heart is perfused with adenosine-8-C¹⁴, or a mixture of ATP-8-C¹⁴ and ATP-γ-P³² of known isotope (C¹⁴/P³²) ratio. The results indicate that any difference between the rate of incorporation of adenosine-C¹⁴ or ATP-C¹⁴ into myocardial nucleosides and nucleotides fraction did not show significance, and also that any difference of the C¹⁴ distribution in the perfusates between adenosine-C¹⁴ and ATP-C¹⁴ perfused by the isolated rat hearts did not show singnificance. When perfused with C¹⁴-and P³²-ATP of known isotope ratio, ATP isolated from the myocardium showed an isotope ratio (C¹⁴/P³²) approximately 5 times greater than that of ATP in perfusion fluid. These results suggest that ATP might be first degraded and later resynthesized intracellularly.