Metabolism of N-nitroso-hydroxyethyl-alkylamine phosphate esters in the rat.

The metabolism of 1-(N-methyl-N-nitrosamino)-ethylphosphate and 1-(N-ethyl-N-nitrosamino)-ethylphosphate in the rat was investigated. The determination of blood clearance, organ clearance, excretion of parent compounds in the urine and the exhalation of radiolabeled CO2 originating from a nitrosaminophosphate demonstrated a rapid metabolism of the compounds. The high activity of alkaline phosphatase in kidney caused a very rapid degradation of the nitrosamino phosphates in kidney homogenate, whereas the compounds were relatively stable in liver homogenate and serum. We, therefore, suggest a rapid degradation of such nitrosamino conjugates, if they are formed at all, in vivo.