Radioimmunoassay for a novel urinary nucleoside, N6-succinyladenosine.

A sensitive radioimmunoassay has been developed for an unusual urinary nucleoside, N6-succinyladenosine (N6-SAR). Antibodies were raised in rabbits and the antibody specificity was established by binding inhibition radioimmunoassay of compounds with structural similarity to N6-SAR. The assay is sensitive enough to detect up to a nanomole of N6-SAR in 1 ml of urine. The mean N6-SAR urinary excretion value for normal adults was 4.09 mg/gm of creatinine with a standard deviation of 1.22. The measurement of N6-SAR in the urines of a number of subjects with metastatic malignant disease suggests that these patients excreted in their urines elevated amounts of N6-SAR in comparison to that in the urines of normal subjects.