Postmortem Changes of ATP and Its Related Compounds in Oyster Tissues in the Presence of Antibiotic Chloramphenicol

Abstract

Chopped and homogenized tissues of oyster were stored in the presence of an antibiotic chloramphenicol (CP) and the postmortem changes of ATP and its related compounds were investigated to clarify the role of endogenous enzymes and bacterial enzymes on these changes. With and without CP, the degradation of ATP to inosine (HxR) in the homogenized adductor muscle, mantle, and gill, or to xanthine (Xt) in the homogenized body trunk proceeded smoothly. Therefore, the breakdown of ATP to HxR or Xt was mainly caused by endogenous enzymes. When the tissue structure is maintained in the chopped tissues, ATP-breakdown by the endogenous enzymes was limited from ATP to IMP in the adductor muscle or to AMP in other tissues and further breakdown proceeded slowly. In the chopped and homogenized tissues, the decrease of IMP and HxR and the increase of hypoxanthine and Xt during the decomposition stage were suppressed at certain levels in the presence of CP. These changes were supposed to be mainly due to the exogenous enzymes.