Nitric oxide production is increased in the spermatic veins of adolescents with left idiophatic varicocele

Background/Purpose: The existence of an excessive release of nitric oxide (NO) within dilated spermatic veins has been recorded in adults with varicocele suggesting a high oxidative stress. The authors investigated whether NO overproduction is already present in the dilated veins of adolescent varicocele and which enzymatic isoforms in the spermatic vein could be expressed. Methods: The study group consisted of 10 adolescent patients affected by left idiophatic varicocele of grade II and Ill. The increase in NO production was established by determination of serum concentration of L-hydroxyarginine (L-NHA) and Nitrite/nitrate (NOx). Both endothelial and inducible NOsynthase (NOS) were investigated by Western blot analysis and by immunohistochemical localization using specific monoclonal fluorescein conjugated antibodies. Results: Serum L-NHA levels were significantly greater in the spermatic veins when compared with the peripheral veins 176.8 +/- 32.3 mu mol/L versus 3.38 +/- 0.64 mu mol/L (P = .0004 Similarly, NOx levels were increased, respectively, 68.2 +/- 16.7 nmol/mL versus 12.9 +/- 2.65 nmol/ml(P = .029). Endothelial NOS was localized in the spermatic vein of varicocele patients, but not overexpressed; the inducible isoform was not detected. Conclusions: Adolescents with varicocele already present an increase in NO within dilated veins. The dilated spermatic vein is not the major source for the increase in NO level. These results could have an implication in the natural history of adolescent varicocele and in programming the ideal time for surgical treatment. Copyright (C) 2001 by W.B. Saunders Company.