摘要
Hunan Province is one of the high incidence areas of nasopharyngeal carcinoma (NPC) in China and ranks the fourth after Guangdong, Guangxi and Fujian. Consequently, the pathogenesis of NPC has been the focus of our study for many years. Induction of experimental NPC by chemical carcinogens began from 1972. Later, NPC in rats was successfully induced by nitroso compounds, especially N, N’-dinitroso-piperazine (DNPZ) which possesses relative organospecificity and is able to induce squamous cell carcinoma of nasopharynx in rats even by subcutaneous injection. NPC induced in rats is slightly different from the NPC of human due to species difference: it often developed as well-dif-
