Urea cycle enzymes in the liver of a dolphin Platanista indi.

Urea cycle enzymes are all shown to be active in dolphin liver. Acetylglutamate-independent cytoplasmic carbamylphosphate synthase is also present. Arginase is a basic protein, although less markedly basic than the dog enzyme. It is 118 per cent activated by heating at 50 degrees. Optimum pH is 10.5. Co++ and Ni++ inhibit the enzyme. AMP deaminase, glutamicoxaloacetic transaminase, glutamate dehydrogenase and ornithine transaminase are also active in dolphin liver.