Detection of nitric oxide stable metabolites in ovarian cyst fluid as evidence of local nitric oxide production

Objective: Although nitric oxide has an important physiological role in controlling the growth of ovarian follicles, the production of NO by ovarian cysts has not been demonstrated. The present study was conducted to evaluate the presence of NO stable metabolites (nitrite and nitrate) in ovarian cystic fluid and to correlate it with the correspective levels in the serum. Methods: The concentration of NO metabolites in both biological fluids was evaluated also as a function of the volume of the cysts. The study involved 15 women undergoing surgical removal of benign cysts. Cystic fluid was aspirated during surgical intervention and a blood sample was contemporarily collected. Nitrite/nitrate concentration was assayed by a specific Griess reaction. Results: The mean levels of NO2-/NO3- were significantly higher in cystic fluid than in serum (p < 0.05), but no correlation between cystic fluid and serum NO metabolites levels. Serum levels of NO-/NO- did not correlate with cyst volume; however, the levels of NO2-/NO3- in cystic fluid were higher than in the smaller cysts. Conclusion: In conclusion, we have detected large amounts of NO2-/NO3- in ovarian cysts and no correlation between NO levels in serum and cystic fluid, supporting the concept of local production of NO metabolites in benign ovarian cysts.