Arginine-to-ornithine ratio

Method

Ratio of plasma arginine concentration to plasma ornithine concentration measured on the same specimen, used to index arginase-mediated diversion of arginine.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Will be confused with plasma arginine concentration alone. The two dissociated in PMID 41534622, where the concentration rose and this ratio did not, so an edge resting on the claim that arginine went up must not be recorded here. Also distinct from the global arginine bioavailability ratio, which divides arginine by the SUM of ornithine and citrulline -- a different denominator, a different number, and frequently reported under the same loose phrase arginine bioavailability.