Correlation between radiotherapy and serumal level of endogenous nitric oxide in patients with nasopharyngeal carcinoma

Objective To explore the correlation between radiotherapy and the serumal level of endogenous nitric oxide (NO) in patient with nasopharyngeal carcinoma (NPC). Methods The levels of NO were detected by nitrate reductase method in sera from 20 patients with NPC at the time points before radiotherapy, immediately after radiotherapy, and one year after radiotherapy. 27 healthy adults were taken as control; their levels of NO were also detected. Results ① The levels of NO in NPC patient before radiotherapy was significantly higher than that in of control group (P0.01). ② The levels of NO in NPC patients immediately after radiotherapy were significantly lower that those before radiotherapy (P0.01). ③ The levels of NO in NPC patients one year after radiotherapy were higher than those in control group and NPC patients immediately after radiotherapy (P0.01), but much lower than those in NPC patients before radiotherapy (P0.05). Conclusion NO may play an important role in the carcinogenesis and development of NPC at molecular level. Concentration monitoring of serumal NO maybe helpful to evaluate the state and prognosis of NPC patients.