Anaerobiosis, recovery from anoxia, and the role of strombine and alanopine in the oyster Crassostrea virginica

Abstract

Tissue-specific metabolism was monitored in gill, mantle, and adductor muscle of the oyster Crassostrea virginica over a time course of 96 h of anoxia followed by 48 h of recovery from anoxia. Succinate and alanine accumulated as products of anaerobic metabolism while aspartic acid was utilized as a substrate of anaerobiosis. The imino acids alanopine and strombine were not produced during anoxia. During aerobic recovery tissue levels of metabolites returned to control levels, succinate within 2 h in mantle and gill and 6 h in muscle, while restoration of alanine levels required about 24 h. Aspartate pools were restored in 4 to 6 h. Alanopine and strombine accumulated during the recovery period. By 2 h of recovery, alanopine content of mantle and gill had risen by 1.3 and 0.5 μmol/g, respectively, while in adductor muscle both alanopine and strombine accumulated with net increases of 2 and 2.7 μmol/g. Imino acid content declined after 6–12 h of recovery returning to control levels by 24 h. The roles of alanopine and strombine in the oyster are not as products of anaerobic metabolism but rather as products of glycolytic function during recovery. The increased metabolic rate associated with the return to aquatic conditions appears to require some glycolytic energy production to meet overall tissue energy requirements of recovery.