Asymmetric dimethylarginine (ADMA) concentration

Method

Circulating asymmetric dimethylarginine in plasma or serum by HPLC, LC-MS/MS or ELISA. Assay platform recorded on the edge -- ELISA and mass-spectrometry values are not interchangeable and differ systematically in absolute concentration.

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 symmetric dimethylarginine, its structural isomer, separated on the same chromatographic run and tabulated on the adjacent line. Only the asymmetric isomer competitively inhibits nitric oxide synthase; the symmetric one is a renal-clearance marker with no direct NOS activity, and the two gave different results in the same schizophrenia meta-analysis. Also distinct from plasma arginine, and from the arginine/ADMA ratio, which belongs to neither node and needs its own if it recurs.