Effects of N‐Nitrosopyrrolidine and N‐Nitrosoproline on the Incorporation of 3H‐Thymidine into the DNA of Various Organs of the Mouse: Tissue Specificity and Effects of Ethanol Consumption

Publisher Website
Google Scholar
Abstract
The effects of the carcinogenic N-nitrosamine N-nitrosopyrrolidine (NPYR) and the non-carcinogenic N-nitrosamino acid N-nitrosoproline (NPRO) on 3H-thymidine incorporation into DNA were evaluated in various organs of male C57BL mice. The N-nitroso compounds were given intraperitoneally 24 hrs before sacrifice in equimolar amounts of (148 .mu.mol/kg b.wt.). Two hours before the mice were killed, they were given an intraperitoneal injection of 3H-thymidine. NPYR, but not NPRO, induced a tissue-specific inhibition of 3H-thymidine incorporation into DNA. The inhibition occurred only in organs reported to be involved in the biotransformation of NPYR, i.e., the liver, lung, and nasal mucosa. Daily oral consumption of ethanol (1.8 ml 30% ethanol for 30 days) had no effects in itself on 3H-thymidine incorporation, but resulted in an enhancement of the inhibitory action of NPYR in the lung and nasal mucosa.