Cytosolic phospholipase A2 and F2 isoprostanes are involved in semen quality and human infertility-A study on leucocytospermia, varicocele and idiopathic infertility.

Phospholipase A2 (PLA2 ) is involved in eicosanoid release, and F2 -isoprostanes (F2 -IsoPs), as free radical-generated eicosanoids released by PLA2 , are indicators of oxidative stress in different human conditions. This study investigated the interplay between cytosolic PLA2 (cPLA2 ), F2 -IsoPs and sperm features in male infertility, when the involvement of oxidative stress has been reported. Semen evaluation was performed following WHO guidelines, sperm ultrastructure was detected by transmission electron microscopy indicating a fertility index, and the percentages of sperm immaturity, apoptosis and necrosis. In sperm cells and seminal plasma, cPLA2 levels were determined by immunological method, whereas F2 -IsoPs by mass spectrometry. Sperm concentration, morphology, vitality and fertility index values were significantly lower in infertile groups compared with fertile men. An increase in sperm apoptosis and necrosis (p < .01), apoptosis (p < .01) and immaturity (p < .001) was detected in leucocytospermia, idiopathic infertility and varicocele, respectively. Seminal cPLA2 showed the highest value in varicocele group (p < .05), whereas seminal F2 -IsoPs increased in varicocele (p < .001) and leucocytospermia (p < .05) groups. In the whole population, F2 -IsoP and cPLA2 levels were positively correlated (p < .05). On the contrary, F2 -IsoPs and cPLA2 were not significantly different when investigated in sperm cells. Our data indicate that fatty acid oxidation/metabolism plays a role in different male reproductive pathological conditions.

The Relationship Between Endothelial Nitric Oxide Synthase Gene (NOS3) Polymorphisms, NOS3 Expression, and Varicocele.

BACKGROUND: Varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. Varicocele is the most common cause of secondary male infertility. Nitric oxide (NO), which has a role on varicocele pathophysiology, is synthesized by endothelial nitric oxide synthase gene (NOS3). OBJECTIVE: In our study, we aimed to explain the relationship between varicocele, three common NOS3 polymorphisms (T-786C, G894T, 4b/a), and NOS3 mRNA expression levels. METHODS: We investigated NOS3 T-786C, G894T, and 4b/a polymorphisms in 102 patients with varicocele and 100 healthy controls. Twenty-four patients and 17 controls were chosen for expression studies based on polymorphism subgroupings. Subgroup 1 includes patients who have no minor allele polymorphisms, and subgroups 2, 3, and 4 have T-786C, G894T, and 4b/a polymorphisms, respectively. RESULTS: The 4b/a polymorphism demonstrated significantly elevated levels in both allele and genotype analysis in the control group compared to the patient group. The G894T polymorphism was statistically elevated for genotypic frequencies in the patient group compared to the control group, but this finding did not extend to allelic frequencies. There were no statistically significant differences in either the allelic or genotypic frequencies between patients and control groups for the T-786C polymorphism. When patient and control expression levels were compared without considering the subgroups, the NOS3 expression level was found to be statistically higher in the patient group. There were no statistically significant differences in the patient and control group expression levels when stratified by subgroup, nor was there any effect of the polymorphisms under study on expression levels. CONCLUSIONS: The 4b/a polymorphism may have a protective effect for varicocelem and G894T polymorphism may contribute to varicocele occurrence by lowering the level of NO. The higher NOS3 expression levels in the patient group may be a kind of dilator compensatory mechanism to protect vascular anatomy in varicocele.

Seminal cyclooxygenase relationship with oxidative stress in infertile oligoasthenoteratozoospermic men with varicocele.

This study aimed to assess the relation of seminal cyclooxygenase COX-1, COX-2 with oxidative stress in infertile oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). In all, 128 men were allocated into fertile men, fertile men with Vx, infertile OAT men without Vx and infertile OAT men with Vx. They were subjected to history taking, clinical examination and semen analysis. Also, seminal COX-1, COX-2, malondialdehyde (MDA) and glutathione peroxidase (GPx) were estimated. Mean levels of seminal COX-1, COX-2 were over-expressed, the mean level of seminal MDA was significantly increased, and the mean level of seminal GPx was significantly decreased in infertile OAT men with Vx compared with other groups. Seminal COX-1 and COX-2 were over-expressed in cases with Vx grade III compared with Vx grades I, II cases and in cases with bilateral Vx compared with unilateral Vx. There was significant negative correlation between seminal COX-1 and COX-2 with sperm concentration, sperm motility, sperm normal morphology, seminal GPx and significant positive correlation with seminal MDA. It is concluded that seminal COX-1 and COX-2 are over-expressed in infertile OAT men with Vx compared with fertile men with/without and infertile OAT men without Vx being associated with oxidative stress, Vx grade and Vx laterality.

Human sperm molecular anatomy: the enzyme 5α-reductase (SRD5A) is present in the sperm and may be involved in the varicocele-related infertility.

The most common cause of male infertility is the testicular varicocele, a condition that impairs production and decreases quality of sperm. Male fertility also strictly depends on androgens acting through their own receptor. The enzyme 5α-reductase (SRD5A) is involved in the conversion of testosterone to 5α-dihydrotestosterone, both required for the development and maintenance of male reproductive function. Here, we evaluated, by western blotting analysis, the presence of SRD5A in human ejaculated spermatozoa and evidenced differences in sperm SRD5A content between healthy donors and varicocele-affected patients. Additionally, SRD5A sperm ultrastructural localization was also assessed by transmission electron microscopy and immunogold assay. We evidenced that SRD5A enzyme is present in the human spermatozoa and that its cellular content is lowered in sperm samples from varicocele patients compared to healthy subjects. The presence of SRD5A in human ejaculated spermatozoa highlights the potential role of this enzyme in sperm physiopathology suggesting that the decrease in its content, by affecting the conversion of testosterone into 5α-dihydrotestosterone, may be an important additional mechanism involved in the harmful effect of varicocele in male fertility.

Glutathione-S-transferase-oxidative stress relationship in the internal spermatic vein blood of infertile men with varicocele.

This study aimed to assess glutathione-S-transferase (GST) enzyme- oxidative stress (OS) relationship in the internal spermatic vein (ISV) of infertile men associated with varicocele (Vx). Ninety five infertile oligoasthenoteratozoospemic (OAT) men associated with Vx were subjected to history taking, clinical examination and semen analysis. During inguinal varicocelectomy, GST, malondialdehyde (MDA) and glutathione peroxidase (GPx) were estimated in the blood samples drawn from ISV and median cubital veins. The mean levels of GST, GPx were significantly decreased and the mean level of GPx was significantly increased in the ISV compared with the peripheral blood. The mean level of GST and GPx in the ISV was significantly decreased, and the mean level of MDA was significantly increased in Vx grade III compared with Vx grade II cases. There was nonsignificant difference in the mean level of GST in the ISV in unilateral Vx cases compared with bilateral Vx cases. There was significant positive correlation of GST with sperm count, sperm motility, GPx and significant negative correlation with sperm abnormal forms, MDA. It is concluded that ISV of infertile men associated with Vx has decreased levels of GST compared with peripheral venous circulation that is correlated with both OS and Vx grade.

Altered metalloproteinase-9 expression as least common denominator between varicocele, inguinal hernia, and chronic venous disorders.

BACKGROUND: Varicocele, inguinal hernia, and clinical manifestations related to chronic venous disorders are often associated, and collagen metabolism together with metalloproteinases (MMPs) alterations may be implicated. The aim of this study was to analyze the relationship between these factors. METHODS: We evaluated tissue and plasma samples from patients with varicocele, inguinal hernia, and great saphenous vein reflux, who underwent surgical treatment for their conditions. We then analyzed and correlated these findings with MMP levels. RESULTS: Significantly higher levels of MMP-1, -2, -12, and -13 were found in patients with inguinal hernia. MMP-9 levels were higher in patients with at least two of the conditions indicated. CONCLUSION: MMP-9 seems to be the common thread in various clinical conditions and is related to a more general and progressive disorder of collagen metabolism.

Varicocele decreases epididymal neutral α-glucosidase and is associated with alteration of nuclear DNA and plasma membrane in spermatozoa.

OBJECTIVE: To assess the relationship between a marker of epididymal function and both the fragmentation of the sperm nucleus and the integrity and maturity of the sperm membrane in patients with or without varicocele. PATIENTS AND METHODS: Semen samples were obtained from men with varicocele grades II and III (n = 60) and from a control group with zoospermia defined as normal (n = 30). Samples were evaluated by a spermiogram, a hypoosmotic swelling test (HOST), neutral α-glucosidase (NAG) enzyme activity, sperm hyaluronan-binding assay (HBA) and DNA fragmentation using a sperm chromatin dispersion (SCD) test. RESULTS: Seminal plasma NAG levels, percentage of sperm bound to hyaluronic acid, HOST-positive cells and sperm quality were significantly lower in the varicocele compared with the control group. Higher levels of sperm DNA fragmentation, as measured by SCD, were also observed in the varicocele group compared with the control group. Seminal NAG activity levels showed a strong negative correlation with DNA fragmentation and a significant positive correlation with the HBA test and the HOST. CONCLUSIONS: Varicocele causes a reduction in NAG activity by the epididymis that is associated with damage to both the membrane and sperm nucleus and a reduction in the seminal parameters. NAG levels were correlated with the quality of the sperm membrane and nucleus. Data suggest that a reduction of fertilization capacity in men during varicocele can result from damage to both the testis and the epididymis.

Human sperm anatomy: different expression and localization of phosphatidylinositol 3-kinase in normal and varicocele human spermatozoa.

Abstract Recent reports support the possible role of PI3K in sperm capacitation and acrosome reaction, although studies regarding PI3K identity in human sperm, under certain disease states such as varicocele, are still lacking. The authors, therefore, examined the expression profile and ultrastructural localization of PI3K in human semen samples, comparing healthy donors and patients with varicocele. The results obtained performing western blotting assay showed decreased PI3K expression in varicocele with respect to the "healthy" sperm. Immunogold labeling revealed human sperm cellular compartments containing PI3K, evidencing it in the head at both the membrane and nucleus and the entire tail, from the middle to the end piece of normal sperm. In varicocele PI3K label was confined to the head, with a strong reduction of specific reaction in the neck, middle piece, and tail. In conclusion, the data suggest that PI3K may play a role in the maintenance of male factor infertility associated with varicocele, and it may be further exploited as an additional molecular marker for the diagnosis of male infertility disorders.

Apurinic/apyrimidinic endonuclease immunoreactivity in germ cells of experimental varicocele-induced rat testes.

Increased germ cell apoptosis is related to oxidative DNA damage; therefore, we investigated whether there was a significant change in apurinic/apyrimidinic endonuclease (APE) in varicoceles. Experimental varicoceles were created by partial ligation of the left renal vein of adult male Sprague-Dawley rats, which were sacrificed at 1, 3 and 6 weeks after varicocele creation. Testicular tissues were sampled for TUNEL, Western blotting and immunohistochemistry. There was a significant increase in apoptotic germ cells in the ipsilateral testes 6 weeks after varicocele creation. Increased activation of p53, Bax and cleaved caspase-3 in the left testes was also noted. APE increased activation until 3 weeks after varicocele creation, and then decreased at 6 weeks after varicocele surgery. The spermatocytes were immunostained for both 8-hydroxy-2'-deoxyguanosine and APE, but the spermatogonia revealed only APE immunopositivity in the defective tubules. These results suggest that repression of APE is an underlying mechanism of augmented p53-dependent apoptosis in varicocele-induced rat testes and that remaining APE in the spermatogonia plays a decisive role in regaining testicular spermatogenic function after varicocelectomy.

Prolidase enzyme activity in varicose venous walls related to sperm count in patients with varicocele.

OBJECTIVES: To investigate peripheral, seminal and varicose venous wall prolidase enzyme activities and their relationships between sperm parameters in patients with varicocele. DESIGN AND METHODS: Prolidase enzyme activities were determined in blood, seminal fluid and varicose vein walls in patients with grade 3 varicocele. Sperm parameters were also measured and the relationships between prolidase enzyme and sperm parameters were assessed by statistical correlation analysis. RESULTS: There was a significant and negative correlation between sperm counts and varicose venous wall prolidase enzyme activities (r = -0.618, p < 0.001) and a positive significant correlation between sperm counts and seminal fluid prolidase enzyme activities (r = 0.676, p < 0.001). None of the parameters were correlated with sperm motility indices. CONCLUSION: Varicose venous wall prolidase enzyme activity could be an important factor in progression of azoospermia and infertility in patients with varicocele.

Expression of NOS isoforms in internal spermatic veins of infertile men with varicocele.

Although varicocele is a relatively common entity encountered in the evaluation of infertile men, the exact pathophysiology still remains unclear. Recently, as previously widely investigated in various parts of human circulatory system, nitric oxide synthase (NOS) and its product, nitric oxide (NO) have been thought to play a role in the development of varicocele and thus male infertility. In this study, we determined the concentration of NO metabolite and the expression of NOS isoforms in the internal spermatic (ISV) and superficial branch of inferior epigastric veins of infertile men with varicocele. The study included 60 infertile men with clinically unilateral or bilateral varicocele. Expression of inducible and endothelial NOS (iNOS and eNOS) isoforms were investigated in tissue arrays of internal spermatic and superficial branch of inferior epigastric veins with immunohistochemistry. NO metabolite (nitrite) levels were measured using the calorimetric method. A significantly higher expression of eNOS was observed in the varicose veins (mean score: 2.25 and 1.55, respectively; p = 0.0001). However, statistically, there was no significant difference for expression of iNOS between varicose and control veins (p = 0.094). The nitrite concentration and NOS expression were not found to be correlated with clinical variables (varicocele grade, maximum varicose vein diameter, and sperm concentration, motility, and morphology) (p > 0.05). As a result, the significantly higher expression of eNOS in ISV may be responsible for the development of varicocele, although this finding is not accompanied by an increase in NO concentration. Still, the pattern of the relationship between varicocele and increased eNOS expression warrants further investigation.

Genetic polymorphisms of glutathione S-transferase M1, T1, and P1, and the assessment of oxidative damage in infertile men with varicoceles from northwestern China.

Our objective was to investigate the genetic polymorphisms of the glutathione S-transferase M1, T1, and P1 genes (GSTM1, GSTT1, and GSTP1) and to assess the oxidative damage in infertile men with varicoceles from northwestern China. A total of 65 infertile men with varicoceles and 30 controls were included in the study. Multiplex polymerase chain reaction and polymerase chain reaction-restriction fragment length polymorphism analyses were used to identify the genotypes. Sperm DNA damage was assessed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL). The levels of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) were measured by high-performance liquid chromatography with electrochemical detection. The activities of malondialdehyde (MDA) and nitric oxide (NO), and the total antioxidant capacity (TAC) were detected by spectroscopic analysis, and sperm characteristics were measured using computer-assisted semen analysis. The frequencies of the GSTM1, GSTT1, and GSTP1 genotypes were not significantly different between the control and patient groups (P > .05). The percentage of TUNEL-positive sperm and the levels of 8-OH-dG, MDA, and NO were higher but the sperm concentration and motility and the TAC were lower in the patients with the GSTM1, GSTT1, and GSTM1/T1 null genotypes than those in the patients with the GSTM1, GSTT1, and GSTM1/T1 present genotypes (P < .05). However, no significant differences were observed between the GSTP1 A/A and A/G+G/G genotypes (P > .05). Our results suggest that the GSTM1 and GSTT1 null genotypes may predispose sperm to increased oxidative damage in infertile men with varicoceles; however, GSTP1 allelic variation was not significantly different between the patient and control groups in this study.

Elevation of both reactive oxygen species and antioxidant enzymes in vein tissue of infertile men with varicocele.

OBJECTIVE: To compare reactive oxygen species (ROS) and antioxidants in internal spermatic vein tissue of men with varicocele and a control group with inguinal hernia. Also to compare the levels of oxidants and antioxidants in infertile and fertile men with varicocele. PATIENTS AND METHODS: 48 varicocele patients and 12 non-varicocele inguinal hernia patients participated in this study. The varicocele group was again divided into two groups--fertile men with varicocele and infertile men with varicocele. Internal spermatic vein tissue samples were obtained. The level of the malondialdehyde (MDA), an indicator of oxidative stress, and the activities of antioxidant enzymes (defense systems) against oxidative stress such as superoxide dismutase (SOD) and catalase (CAT) were estimated in these tissue samples. RESULTS: The mean level of MDA in the varicocele group was significantly higher than in the hernia group, whereas the levels of antioxidants (SOD and CAT) were significantly lower in the varicocele group than in the hernia group. When compared with the subgroups of the varicocele group, the MDA levels and SOD and CAT activities were significantly higher in the infertile varicocele group than in the fertile varicocele group. CONCLUSIONS: Antioxidant enzyme levels generally decrease due to a high consumption in varicocele patients. On the contrary, in our study both MDA and antioxidant enzymes increased in the internal spermatic venous wall of infertile varicocele patients. This situation may be explained by an adaptation against oxidative stress in varicocele, which could be defined as a chronic process.

Potential role of poly(ADP-ribose) polymerase activation in the pathogenesis of experimental left varicocele.

The aim of this study was to evaluate whether the poly(adenosine diphosphate[ADP]-ribose) polymerase (PARP) pathway is activated by experimental left varicocele. Rats underwent partial ligation of the left renal vein to induce experimental varicocele, and left testes were analyzed 13 weeks after surgery. Tubule degeneration was evaluated by Johnsen score. Expression of 4-hydroxy-2-nonenal (4-HNE)-modified proteins, PARP-1, and poly(-ADP-ribose) (PAR) was detected by immunohistochemistry and Western blot. The degree of apoptosis within testes was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling. Light microscopy revealed testicular damage comprising various degrees of seminiferous tubule degeneration. Germ cell apoptotic index and 4-HNE, PAR, and PARP-1 expression in germ cells increased after varicocele induction. Increased oxidative stress and PARP overactivation in testes might be important with regard to impaired testicular function associated with varicocele.

Potential role of p38-mitogene-activated protein kinase and nuclear factor-kappa B expression in testicular dysfunction associated with varicocele: an experimental study.

The aim of this study was to investigate p38-mitogene-activated protein kinase (p38-MAPK), nuclear factor-kappa B (p65-NF-kB) and inducible nitric oxide synthase (iNOS) expression in an experimental model of varicocele in the rat testis. Male Wistar albino rats (n = 18) were divided into three equal groups: control group, sham operated group and left varicocele-induced group. Malondialdehyde (MDA), nitric oxide (NO) and reduced glutathione (GSH) levels were biochemically assessed, and the p38-MAPK and NF-kB activity, and iNOS expression were immunohistochemically studied in the right and left testicles of rats from each group. The GSH levels were significantly decreased, whereas the level of MDA and NO was significantly increased in the testicular tissues of rats in varicocele group compared with those of the control and sham groups. There was a marked staining for iNOS, p38-MAPK and p65-NF-kB expression in rats of varicocele group compared with the sham group. There was no positive staining in rats of control group. There were significant differences in biochemical, histological and immunohistochemical studies, but no significant differences were noted between other groups. p38-MAPK and p65-NF-kB activation, and iNOS expression have a significant role in varicocele-induced testicular dysfunction.

Glutathione S-transferase M1 and T1 polymorphisms in Turkish patients with varicocele.

Several studies have shown that high oxidative stress levels are associated with varicocele. The GST (glutathione S-transferase) family of genes is critical in the protection of cells from oxidative stress because they utilise as substrates a wide variety of products of oxidative stress. The objective of this study was to assess the relationship between genetic polymorphism in GST-M1 and GST-T1 and varicocele using 109 varicocele patients and 123 controls. Varicoceles were clinically graded as Grade 1, Grade 2 and Grade 3. GST-M1 and GST-T1 genes were determined by polymerase chain reaction. Although the GST-M1 null genotype was higher in Grade 3 than in Grade 1, 2 and controls, there were no statistical differences between control group and varicocele groups according to GST-M1 and GST-T1 null genotype. Men with varicocele do not have more GST-M1 and GST-T1 null polymorphisms than men without varicocele. Additional studies are needed to assess the exact mechanism by which the varicocele corresponds to elevated ROS levels.

Sperm caspase-9 in oligoasthenoteratozoospermic men with and without varicocele.

OBJECTIVE: To assess sperm caspase-9 activity in infertile oligoasthenoteratozoospermic (OAT) men with and without varicocele. DESIGN: Prospective. SETTING: Academic setting. PATIENT(S): Eighty men: healthy fertile control subjects (n = 20), OAT (n = 25), and OAT associated with left-side varicocele (n = 35). INTERVENTION(S): History taking, clinical examination, semen analysis,assessment of seminal caspase-9. MAIN OUTCOME MEASURE(S): Semen analysis, sperm caspase-9. RESULT(S): Sperm caspase-9 was significantly increased in infertile OAT men associated with varicocele compared with OAT men without varicocele and healthy fertile control subjects. Sperm casapse-9 activity demonstrated significant negative correlation with sperm count, sperm motility, sperm velocity, sperm linear velocity, sperm linearity index, and sperm normal morphology. CONCLUSION(S): Sperm caspase-9 is exaggerated in infertile OAT cases with varicocele compared with infertile OAT cases without varicocele or healthy fertile men. Sperm caspase-9 demonstrated significant negative correlation with semen variables.

Roles of matrix metalloproteinases in the etiology of inguinal hernia.

INTRODUCTION: The fascia transversalis is accepted as one of the anatomical structures that can prevent hernia formation. Degradation of collagen within the fascia transversalis is one of the known reasons for the development of inguinal hernia. In the present study, we investigated the roles of matrix metalloproteinases (MMPs), specifically MMP-1, MMP-2, and MMP-9 in the etiology of inguinal hernia. MATERIALS AND METHODS: This prospective study included 60 inguinal hernia patients: 30 patients had indirect inguinal hernia and 30 patients had direct inguinal hernia. An additional 30 patients operated for reasons other than hernia in the inguinal canal were included as a control group. All patients underwent operations at Istanbul Training and Research Hospital between 1 June 2009 and 1 December 2009. Tissue specimens were taken from the fascia transversalis from patient and control groups during the operation, and MMP-1, MMP-2, MMP-9 values were investigated using immunohistochemical methods. RESULTS: Significantly higher values of MMP-1, MMP-2, MMP-9, were found in inguinal hernia cases than in the control group (P = 0.0001, P = 0.007, P = 0.021, respectively). CONCLUSION: Increased MMP-1, MMP-2, MMP-9 values play a role in the etiology of inguinal hernia. Since weakening may also occur in other tissues in addition to the floor of inguinal canal in inguinal hernia patients, the association of arterial aneurisms and connective tissue diseases should also be investigated in these patients.

Heme oxygenase enzyme activity in seminal plasma of oligoasthenoteratozoospermic males with varicocele.

This work aimed to assess seminal plasma heme oxygenase (HO) enzyme activity in oligoasthenoteratozoospermia (OAT) males with varicocele. Ninety-three men were divided according to their sperm count and clinical examination into: healthy fertile controls (n = 34), OAT without varicocele (n = 37) and OAT associated with varicocele (n = 22). They were subjected to semen analysis and estimation of seminal plasma HO enzyme activity in the form of bilirubin concentration. Seminal plasma HO enzyme activity decreased significantly in OAT cases compared with controls. Seminal plasma HO in OAT cases associated with varicocele decreased significantly compared with OAT cases without varicocele and healthy controls (mean +/- SD; 109.2 +/- 29.5, 283.6 +/- 88.4, 669.5 +/- 236.1 nMol bilirubin/mg ptn/min, P < 0.001). There was positive correlation between seminal plasma HO enzyme activity and sperm concentration, per cent of motile spermatozoa, number of motile spermatozoas ml(-1) and significant negative correlation with sperm abnormal forms per cent. It is concluded that varicocele has a negative impact on seminal HO enzyme activity. Therefore, improved seminal picture after correcting varicocele repair might be related, in part, to improved HO action(s).

Increased testicular 8-hydroxy-2'-deoxyguanosine (8-OHdG) and inducible nitric oxide synthetase (iNOS) and nuclear factor κB (NF-κB) expressions in experimental rat varicocele.

OBJECTIVES: To assess nuclear factor-kappaB (NF-kappaB), inducible NO synthase (iNOS) immunohistochemically, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) biochemically, which are sensitive biological markers of oxidative damage and stress, in testes with experimental varicocele. MATERIALS AND METHODS: Adult rats were randomly divided into three groups. Control group (n: 10), sham group (n: 10), varicocele group (n: 10). Of 14 rats undergoing partial ligation of the left renal vein, 10 rats had developed dilation of the left spermatic vein when evaluated 3 months after varicocele-inducing surgery. The rats were sacrificed after 3 months of the varicocele-inducing surgery. Ipsilateral and contralateral testes were examined for 8-hydroxy-2'-deoxyguanosine (8-OHdG) biochemically, inducible NO synthase (iNOS) and nuclear factor-kappaB (NF-kappaB) expression immunohistochemically. RESULTS: Inducible NO synthase (iNOS), nuclear factor-kappaB (NF-kappaB) expressions and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in both testes of varicocele group were markedly higher compared with control and sham groups (p < 0.01). There was no difference between control and sham groups (p > 0.05). CONCLUSIONS: Regarding to our results, we suggest that varicocele may produce oxidative stress in both of testes, and we believe that this stress may play a role in male fertility.