POSTMORTEM CHANGES OF ATP AND ITS RELATED-COMPOUNDS IN OYSTER TISSUESIN THE PRESENCE OF ANTIBIOTIC CHLORAMPHENICOL

Chopped and homogenized tissues of oyster were stored in the presence of an antibiotic chloramphenicol (CP) and the postmortem changes of AT P and its related compounds were investigated to clarify the role of e ndogenous enzymes and bacterial enzymes on these changes. With and wit hout CP, the degradation of ATP to inosine (HxR) in the homogenized ad ductor muscle, mantle, and gill, or to xanthine (Xt) in the homogenize d body trunk proceeded smoothly. Therefore, the breakdown of ATP to Hx R or Xt was mainly caused by endogenous enzymes. When the tissue struc ture is maintained in the chopped tissues, ATP-breakdown by the endoge nous enzymes was limited from ATP to IMP in the adductor muscle or to AMP in other tissues and further breakdown proceeded slowly. In the ch opped and homogenized tissues, the decrease of IMP and HxR and the inc rease of hypoxanthine and Xt during the decomposition stage were suppr essed at certain levels in the presence of CP. These changes were supp osed to be mainly due to the exogenous enzymes.