The environmental carcinogens N-nitrosopyrrolidine (NPYR) and N′-nitrosonornicotine (NNN) were incubated with human liver microsomes to test for the presence of enzymes catalyzing α-hydroxylation, which is likely to be an activation mechanism for these compounds. Both nitrosamines underwent α-hydroxylation; rates were higher for NPYR than for NNN, as observed in rats. The results indicate that both NPYR and NNN can be metabolically activated by human liver microsomes.
Bibliographical noteFunding Information:
This study was supported by National Cancer Institute Grants CA 21393 and CA 23901. Stephen S. Hecht is recipient of National Cancer Institute Research Career Development Award 5K04-CA 00124.