[Induction of cysts in adult rats by means of sodium nitrite after infection with avian sarcoma virus].

Trials were conducted to study the possible effect of sodium nitrite administered in drinking water as exerted upon carcinogenesis induced by the sarcoma virus in the organisms of adult rats during a five-month period of observation. No clinical changes were observed in these rats during the test period. On the 125th day of age the rats were subjected to post-mortem examination. Cysts were found in seven of twenty rats (36.8%), as compared with the zero induction in the control groups. The cysts occurred in the renal region and in thymus. They were as large as a pea up to the size of an egg and contained serous or slightly haemorrhagic liquid. There is a description of the macroscopic structure of the studied cysts. Interstitial pneumonia was observed in three cases, including the control group. The results show that sodium nitrite may act as a promoter in the carcinogenesis of rats induced by avian sarcoma virus.