The functions of octopine dehydrogenase and D-lactate dehydrogenase in the pedal retractor muscle of thedog whelk Nassarius coronatus (Gastropoda: Nassariidae)

The pedal retractor muscle of Nassarius coronatus, unlike most mollusc muscles, contains high activities of both octopine dehydrogenase (159 IU g^-1 wet wt muscle) and D-lactate dehydrogenase (40 IU g^-1 wet wt muscle). Pedal retractor muscles show accumulation of octopine (increase of 4.7 mol g^-1 wet wt muscle), and a fall in arginine phosphate concentration (decrease of 4.1 mol g^-1 wet wt musscle) after exercise. During recovery from exercise, octopine returns to resting levels after about 120 min, D-lactate accumulates (5.1 mol g^-1 wet wt muscle), and arginine phosphate returns to resting levels within 30 min. D-lactate (2.0 mol g^-1 wet wt muscle) accumulates during long-term exposure to air. The results show that octopine dehydrogenase and D-lactate dehydrogenase can function to catalyze the terminal step of glycolysis during muscle anoxia associated with these different physiological states.