Anaerobic metabolism of erythrocytes of the arcid clam Scapharca inaequivalvis (Bruguiere): effects of cadmium

Abstract

1. 1. Anaerobic metabolism was studied in erythrocytes of the bivalve Scapharca inaequivalvis and compared with other tissue cells. In all cells aspartate reserves are utilized and alanine and succinate accumulate. 2. 2. Erythrocytes are distinct from other tissues as regards the anerobic energy supply. Phosphoarginine is not stored in the erythrocytes. The low glycogen content and the absence of glycogen phosphorylase indicate that the former cannot serve as anaerobic fuel. 3. 3. During 24 hr of anaerobiosis the energy charge in the erythrocytes decreased from 0.83 to 0.64. 4. 4. Extremely high concentrations of free β-alanine were detected in the erythrocytes. 5. 5. Plasma glucose concentration increased from 0.086 to 0.228 μmol per ml during 96 hr of anaerobiosis. 6. 6. Exposure to 50 ppb Cd during 6 weeks did not influence the energy charge during subsequent anaerobiosis, but the increase of alanine was significantly lowered.