Adenosine Triphosphate from Barium-Acid Insoluble Residues

Summary A procedure has been described for the isolation of adenosine triphosphate from barium-nitric acid insoluble residues prepared from whelk foot muscle and rabbit striated muscle. The ATP so isolated is in-distinguishable physiologically from ATP prepared according to the standard procedure of Needham but is only slightly soluble in strong acid. It is present in the smooth muscle of the whelk in much larger amounts than in striated rabbit muscle. Treatment of a similar residue from beef heart yielded a compound which chemically and physiologically resembled ADP.