[Protective effects of inhibition of tissue nitric oxide in the initial stage against tardive injury of testicular spermatogenic function: experiment with rats].
OBJECTIVE
To study the protective effects of inhibition of tissue nitric oxide in the initial stage against the tardive injury of contralateral testicular spermatogenic function after unilateral testicular torsion.


METHODS
56 prepubertal Sprague-Dawley rats were randomly divided into 4 equal groups: placebo group undergoing rotation of left testis 720 degrees clockwise for 4 h, fixing thereof to the scrotum, and then intravenous injection of normal saline; cyclosporine group, undergoing intraperitoneal injection of cyclosporine once daily for 1 month after the testicular rotation and fixation; NG-methyl L-arginine (L-NMMA) group, undergoing intravenous injection of L-NMMA 30 mg/kg 30 min before the testicular rotation; and sham-operation group, undergoing isolation and suture of testis only. The right (untwisted) testes were removed from 7 rats from each group 1 week and 2 months after surgery. The malondialdehyde (MDA) level and nitrous oxide (NO)/nitrogen oxide synthase (NOS) content were evaluated. Histological examination was conducted. The mean seminiferous tubule diameter (MSTD) was assessed. The level of MHC peptide-tetramer complex was determined by flow cytometry.


RESULTS
The levels of MDA, NO, NOS, and MHC peptide-tetramer complex of the L-NMMA, placebo, and cyclosporine groups one week after surgery were all significantly higher than those of the sham operation group (all P < 0.05). The levels of MDA, NO, NOS, and MHC peptide-tetramer complex of the L-NMMA group were all significantly lower then those of the placebo group (all P < 0.05). The pathological damage of the contralateral testis in early and late stages in the L-NMMA group was lighter than in the placebo group.


CONCLUSIONS
By inhibiting tissue NO production in focal organizations during the early period, L-NMMA reduces the damages inthe testis contralateral to the testis undergoing unilateral torsion.
Lin
Xiao-kun
XK
Department of Pediatric Surgery, Affiliated Yuying Children's Hospital of Wenzhou Medical College, Wenzhou 325027, China.
Qin
Le
L
Chen
Cong-de
CD
Han
Yi-xiang
YX
Chen
Xiao-ming
XM
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012671:Seminiferous Tubules / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D013086:Spermatic Cord Torsion / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D019323:omega-N-Methylarginine / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D008315:Malondialdehyde; D019001:Nitric Oxide Synthase