Uricolytic Enzymes in Liver of the Dipnoan Protopterus aethiopicus

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Science  30 Sep 1966:
Vol. 153, Issue 3744, pp. 1653-1654
DOI: 10.1126/science.153.3744.1653


The enzymes uricase, allantoinase, and allantoicase have been measured in liver preparations of the African lungfish Protopterus aethiopicus. The levels for these enzymes in lungfish liver suggest that the amount of urea formed in vivo in Protopterus via a uricolytic pathway may be greater than that derived via the Ornithine-urea cycle. The operation of a "purine cycle" in lungfish liver is proposed.