Metabolism of nitrosamines in vivo. V Investigation on 14CO2 exhalation, liver RNA labelling and isolation of two metabolites from urine after administration of [2, 5-14C-]dinitrosopiperazine to rats.

The synthesis of N, N'-dinitrosopiperazine and N-nitrosopiperazine, both 14C-labelled in the 2-and 5-position is described. After i.p. application of 10 mg/69.5 muCi/kg[2, 5-14C]-N, N'-dinitrosopiperazine to rats no labelled 7-methylguanine was detected in the liver RNA; 1% of the radioactivity was exhaled as 14CO2, 1% excreted via the bile and about 40% excreted in the urine. Two of the urine metabolites were identified as 3-hydroxynitrosopyrrolidine and 1-nitrosopiperazinone-(3).