State analysis of endogenous cyanate ion in human plasma.

Cyanate ion is continuously produced by spontaneous degradation of urea both in healthy human blood and in blood of patients with uremia on intermittent hemodialysis. The cyanate ion is trapped irreversibly by amino groups as N-carbamyl groups and reversibly by sulfhydryl groups as S-carbamyl groups. Consequently, these reactions keep the cyanate ion levels in plasma extremely low. Plasma proteins may play an important role in the detoxication of cyanate ion.