Critical evaluation of plasma and LDL oxidant-trapping potential in hemodialysis patients.

BACKGROUND: We investigated whether the total peroxyl radical-trapping antioxidant potential (TRAP) assay, which has recently been proposed as a gauge of oxidative stress, could serve to evaluate plasma and low density lipoprotein (LDL) antioxidant state in hemodialysis (HD) patients. METHODS: TRAP was determined by the lag time of the chemiluminescence reaction induced by azo-initiator-catalyzed linoleic acid peroxidation in the plasma and corresponding LDL preparations of 23 HD patients and 22 healthy subjects. Antioxidant systems, including glutathione peroxidase (GSH-Px), ascorbate, vitamin E, and uric acid, oxidative stress markers including malondialdehyde (MDA), carbonyls, and advanced oxidation protein products (AOPP), and lipids, including cholesterol and triglycerides, were also determined in the plasma. RESULTS: Both plasma and LDL-TRAP were significantly increased in HD patients despite decreased GSH-Px and ascorbate and increased MDA, carbonyl, and AOPP plasma levels. Plasma TRAP values were closely related to both uric acid and AOPP levels, and LDL-TRAP values were related to triglycerides and AOPP levels. In vitro studies showed that: (a) plasma TRAP of control plasma increased regularly with supplementation of uric acid, although not reaching that of HD plasma with similar uric acid levels; (b) the addition of human serum albumin-AOPP also regularly increased control plasma TRAP, but was close to that of HD plasma with similar AOPP levels; and (c) LDL-TRAP was increased following LDL enrichment with triglycerides. CONCLUSION: Our study demonstrates that TRAP is not a relevant parameter for evaluating plasma or LDL antioxidant capacity in HD patients, due to the high plasma levels of uric acid, triglycerides and AOPP, which by themselves do not exert efficient antioxidant activity in vivo, but in vitro are able to scavenge the peroxyl radicals involved in the TRAP assay.     

Allopurinol does not increase free radical scavenging capacity during reperfusion in coronary artery bypass graft patients

OBJECTIVES: Allopurinol protects the heart against ischaemic events during coronary artery bypass grafting (CABG), possibly because of its antioxidant properties. This double-blind study was designed to investigate whether allopurinol (1 g), given before cardiopulmonary bypass and prior to the opening of cross-clamping, has an antioxidant effect in CABG patients by measuring plasma total peroxyl radical scavenging capacity. DESIGN: Twenty-seven patients with stabile angina were randomized into allopurinol (n = 14) or placebo (n = 13) groups. RESULTS: During 10 min reperfusion, plasma hypoxanthine and xanthine concentrations increased only in the allopurinol group, whereas uric acid concentrations decreased. Total peroxyl radical scavenging capacity (TRAP) decreased from the initial value at all measuring points in both groups. CONCLUSIONS: The reducing effect of allopurinol on free radical generation cannot be seen in TRAP values, obviously because the uric acid concentration of plasma decreases markedly. The positive clinical effects of allopurinol in CABG patients may arise from its direct oxygen free radical scavenging function.     

Allopurinol Does Not Increase Free Radical Scavenging Capacity During Reperfusion in Coronary Artery Bypass Graft Patients

Objectives: Allopurinol protects the heart against ischaemic events during coronary artery bypass grafting (CABG), possibly because of its antioxidant properties. This double-blind study was designed to investigate whether allopurinol (1 g), given before cardiopulmonary bypass and prior to the opening of cross-clamping, has an antioxidant effect in CABG patients by measuring plasma total peroxyl radical scavenging capacity. Design: Twenty-seven patients with stabile angina were randomized into allopurinol (n = 14) or placebo (n = 13) groups. Results: During 10 min reperfusion, plasma hypoxanthine and xanthine concentrations increased only in the allopurinol group, whereas uric acid concentrations decreased. Total peroxyl radical scavenging capacity (TRAP) decreased from the initial value at all measuring points in both groups. Conclusions: The reducing effect of allopurinol on free radical generation cannot be seen in TRAP values, obviously because the uric acid concentration of plasma decreases markedly. The positive clinical effects of allopurinol in CABG patients may arise from its direct oxygen free radical scavenging function.     

Comparison of glycosidase levels in bovine seminal plasma

Seven glycosidases (beta-N-acetylglucosaminidase, alpha-fucosidase, beta-galactosidase, acid alpha-glucosidase, beta-glucuronidase, acid and neutral alpha-mannosidase) were analysed in seminal plasma from the first and second successive ejaculates in normal Ayrshire bulls. In comparison to our previous data the results indicate that beta-N-acetylglucosaminidase, beta-galactosidase and beta-glucuronidase are derived mainly from epididymal secretions, while alpha-fucosidase and particularly neutral alpha-mannosidase originate additionally from the spermatozoan cytoplasmic droplets. The seminal vesicles appear to contribute particularly to the seminal plasma acid alpha-glucosidase and acid alpha-mannosidase activities. The seminal plasma enzymes derived from the epididymis and cytoplasmic droplets were suppressed in semen samples with low sperm density or with high numbers of abnormal spermatozoa. The epididymal and seminal vesicle enzymes could be utilized in assessment of the secretory/functional capacity of these glands.     

Seminal antioxidant capacity in pre- and postoperative varicocele

In order to explore the impact of surgical treatment on antioxidant defense system in varicocele (VAR), we evaluated seminal total antioxidant capacity (TAC) in 25 patients affected by VAR, in 14 patients studied 10-24 months after varicocelectomy (post-VAR) and separated into normo- and oligospermic groups, and in 24 non-VAR control patients with seminal parameters matched to patients with VAR in the oligo- and normospermic groups (7 subjects with idiopathic oligospermia and 17 normal fertile subjects). TAC was measured in seminal plasma with the system H(2)O(2)-metamyoglobin as a source of radicals, which interact with a chromogen 2,2',-azinobis (3-ethylbenzothiazoline-6-sulphonate) (ABTS), generating a radical cation spectroscopically detectable. The presence of antioxidants induces a lag time in the production of ABTS cation proportional to the concentration of antioxidant compounds. When whole groups of patients were analyzed, lag values were significantly higher in VAR vs non-VAR controls (mean +/- SEM, 106.6 +/- 8.8 seconds vs 78.7 +/- 8.8 seconds) but were not modified by surgery (mean +/- SEM, 105.8 +/- 8.6 seconds). In groups separated according to seminal parameters, oligospermic VAR presented significantly higher lag values than oligospermic controls. Finally, when exploring a possible association of TAC with seminal parameters, we found a significant correlation between lag and sperm motility only in patients with VAR who were in the normospermic group (r = 0.65, P <.01). This correlation was not yet manifest post-VAR. In conclusion, surgical treatment does not seem to modify absolute values of TAC but influences its fine regulation and relationships with sperm motility.     

Relationship between seminal ascorbic acid and sperm DNA integrity in infertile men

Ascorbic acid has recently been reported to protect sperm DNA from the damage induced by exogenous oxidative stress in vitro. But, there is no report on seminal ascorbic acid and sperm DNA fragmentation in infertile men. In this study, we asked whether sperm DNA damage correlates with seminal ascorbic acid levels. Sperm DNA fragmentation index (DFI) was analysed in 75 men by flow cytometry after acridine orange staining. We also measured the levels of seminal plasma ascorbic acid and total antioxidant capacity. Abnormal sperm DNA integrity (DFI >or= 30%) was observed in 12% of the patients with normal semen parameters and in 52% of the patients with abnormal semen parameters. There were significant correlations between the level of DFI and conventional semen parameters including sperm count, motility and morphology (r = -0.29, -0.55 and -0.53 respectively; p < 0.05). Seminal ascorbic acid level was significantly lower in the patients with leucospermia than the patient with normal semen parameters. Interestingly, a significantly greater percentage of men with abnormal DFI were observed in the patients with low levels of seminal ascorbic acid compared with those with normal or high levels of ascorbic acid (59% vs. 33%, p < 0.05). Men with insufficient seminal ascorbic acid frequently have sperm DNA damage.     

Effect of folic acid and zinc sulphate on endocrine parameters and seminal antioxidant level after varicocelectomy

Varicocele is among the most common problems which may lead to male infertility. Spermatogenesis is impaired as a consequence of this vascular defect, through mechanisms that are not well described. This study aimed to evaluate serum hormonal level (inhibin B, FSH and testosterone) and seminal plasma antioxidant defence levels after folic acid and zinc sulphate administration in varicocelectomised patients. Participants were randomly allocated to four experimental groups. Our randomisation schedule was as follows: zinc sulphate/folic acid, folic acid, zinc sulphate and placebo. The patients underwent varicocelectomy, before which a blood and semen sample were obtained and also three and six months after varicocelectomy for evaluation of blood hormonal level (FSH, testosterone, inhibin B) and seminal oxidative stress status (nitric oxide, superoxide dismutase, total antioxidant capacity). Patients in different groups took orally one capsule per day after dinner following varicocelectomy for 6 months. A significant rise in peripheral blood inhibin B and seminal plasma activity was detected in the zinc sulphate/folic acid group after 6 months. The present clinical trial indicates a change in the hormonal status of varicocelectomised patients following long‐term administration of zinc sulphate and folic acid.     

Enhanced chemiluminescence assay vs colorimetric assay for measurement of the total antioxidant capacity of human seminal plasma

Although the enhanced chemiluminescence assay is commonly used to measure the nonenzymatic total antioxidant capacity (TAC) of the human seminal plasma, it is cumbersome, expensive, and time-consuming. We describe herein an alternate method to measure TAC that is based on the ability of antioxidants in seminal plasma to interfere with a reaction between 2,2'-azino-di-[3-ethylbenzthiazoline sulphonate] and metmyoglobin with H(2)O(2). This reaction produces a relatively stable blue-green color with absorbance maxima at 600 nm. We compared this colorimetric assay with our established chemiluminescence method and assessed quality control parameters (ie, intra-assay and interassay variabilities) in addition to intraobserver and interobserver differences. Our results show that the colorimetric assay was fairly predictive of antioxidant capacity similar to the chemiluminescence assay (P <.001). Furthermore, there was a high level of agreement between the duplicate measures by the same observer (intraobserver) and intra-assay variability, with a concordance correlation coefficient of 0.99. The interassay coefficient of variation was 4.7% (overall). The mean +/- SD of the difference between the 2 observers was 2.98% +/- 4.1%. In conclusion, we found that the colorimetric assay is a reliable and accurate method to evaluate seminal TAC, and it could be used as a simpler, rapid, and cheaper alternative to the chemiluminescence assay.     

Impaired seminal antioxidant capacity in human semen with hyperviscosity or oligoasthenozoospermia.

Antioxidant capacity of seminal plasma was evaluated in 120 semen samples subdivided into asthenozoospermic and oligoasthenozoospermic specimens with normal consistency and into asthenozoospermic and oligoasthenozoospermic specimens with hyperviscosity. Semen samples (n = 25) from normozoospermic donors were used as a control group. Scavenger antioxidant capacity of reactive oxygen species was evaluated by superoxide dismutase and catalase activity measurements, whereas the chain-breaking antioxidant efficiency was detected by total antioxidant status assessment. In semen with normal viscosity, unaltered enzymatic and nonenzymatic antioxidant capacity was revealed in the asthenozoospermic specimens, whereas low superoxide dismutase activity was detected in oligoasthenozoospermic samples. On the contrary, impairment of both the scavenger and chain-breaking antioxidative systems was revealed in asthenozoospermic and oligoasthenozoospermic hyperviscous ejaculates, regardless of sperm count. Catalase activity and total antioxidant status values were also reduced in the 2 subgroups of hyperviscous ejaculates compared with their respective matched controls, whereas similar superoxide dismutase activities were detected in oligoasthenozoospermic samples with normal and high consistencies. These results suggest that asthenozoospermia could be related to an antioxidant deficiency only in combined ejaculate pathologies, and that a severe impairment of the low and high molecular weight seminal antioxidative capacities could be associated with semen hyperviscosity.     

Identification of fatty acids in canine seminal plasma

Seminal plasma contains various biochemical components associated with sperm function. However, there is limited information regarding the fatty acid composition of seminal plasma and their effect on sperm. The aim of this study was to identify the fatty acid content in canine seminal plasma using gas chromatography. Twelve ejaculates were studied, the seminal plasma was obtained by centrifugation and then the lipids were extracted, methylated and analysed by chromatography. The total lipids in the seminal plasma were 2.5 ± 0.3%, corresponding to 85% saturated fatty acids (SFA) and 15% unsaturated fatty acids (UFA). The greatest proportions of SFA were palmitic acid (30.4%), stearic acid (23.4%) and myristic acid (5.3%) and of UFA oleic acid (9.0%). Therefore, the protocols and techniques used enabled the identification of 18 different fatty acids in canine seminal plasma, which constitutes a good method to evaluate and quantify the fatty acid profile in this species.     

Increased total antioxidant capacity in seminal plasma of varicocele patients: a multivariate analysis

To investigate seminal antioxidant systems and their correlation with hormonal pattern in varicocele patients, we studied 33 varicocele (VAR) patients (12 oligozoospermic, 21 normozoospermic) and 34 non-VARs (10 idiopathic oligozoospermic, 24 normozoospermic). Non-enzymatic total antioxidant capacity (TAC) was measured using H(2)O(2)-metamyoglobin, which generates the radical form, spectroscopically detectable, of the chromogen 2,2',-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS): time till appearance (Lag) of ABTS*(-) signifies antioxidant concentration. Lag was significantly longer in VARs than controls suggesting ineffective utilization of antioxidants. A significant direct correlation (r = 0.65, p < 0.01) of Lag with sperm count was observed in non-VARs, while in VARs it was inverted, as well as with hematic FSH levels. A multivariate analysis including FSH, Lag, progressive spermatozoa, oligozoospermia and varicocele indicated a strong inverse correlation between FSH and motility (r(2) = 0.31, p > F = 0.0007), not modified by Lag (r(2) = 0.31, p > F = 0.002). Their inverse correlation with Lag may suggest that higher FSH levels, improving sperm antioxidant efficiency, counterbalance varicocele-induced dyspermia.     

The effects of dietary lycopene supplementation on human seminal plasma

OBJECTIVE: To investigate whether lycopene levels in blood and seminal plasma increase after dietary supplementation with a natural source of the compound, and whether any potential increase of lycopene levels in semen translates into increased free-radical trapping capacity in the seminal plasma. METHODS: Reactive oxygen species are detrimental to the health and function of spermatozoa. Semen contains enzymatic and non-enzymatic defence mechanisms to combat such species, and lycopene, a dietary antioxidant, forms part of the non-enzymatic arm. Immuno-infertile men have significantly lower levels of lycopene in their semen, and oral lycopene therapy can improve various seminal variables in idiopathic infertility. Whether this improvement is a direct consequence of increased lycopene levels in semen, resulting in an increased radical scavenging ability, remains unknown. Blood and seminal lycopene levels were measured in healthy volunteers, using high-performance liquid chromatography, before and after a period of dietary supplementation. The antioxidant capacity of seminal plasma was also assayed to determine if supplementation results in a measurable increase in seminal radical scavenging ability. RESULTS: There were statistically significant increases in blood and seminal plasma lycopene levels after dietary supplementation. The increase in seminal and blood lycopene levels showed a strong positive correlation (r = 0.84, P < 0.05). There was no measurable increase in the total radical scavenging capacity of semen. CONCLUSION: This study confirms the presence of lycopene in human semen, the levels of which can be significantly increased after dietary supplementation with a natural source of lycopene. Further studies to establish whether this would also be the case in infertile men, with possible associated improvements in their seminal quality, are warranted.     

Antioxidant activity of seminal plasma in fertile and infertile men

This study was conducted to evaluate and compare the total antioxidant capacity among fertile and infertile men. Thirty infertile patients and 20 fertility-proven healthy donors with normal sperm analysis were included in the study. Total antioxidant capacity, zinc and fructose levels of seminal plasma, and various sperm parameters were compared among fertile controls and idiopathic infertility patients prospectively. The mean antioxidant capacity of fertile controls (2.02 +/- 0.16 mmol/L) was significantly higher than that of the infertile patients group (1.78 +/- 0.23 mmol/L) (p < .01). Furthermore, asthenozoospermic and asthenoteratozoospermic groups had significantly lower mean antioxidant values (1.73 +/- 0.11 and 1.64 +/- 0.13, respectively) when compared to fertile control group (p < .01). The mean fructose level was significantly lower in the fertile control group and mean zinc level was significantly lower in the entire infertile group. On the other hand, antioxidant capacity is positively correlated to sperm motility (p = .001). Decreased antioxidant capacity was associated with impaired sperm function as a result of either increased ROS production or insufficient antioxidant capacity.     

Reactive oxygen species in semen of infertile patients: levels of superoxide dismutase- and catalase-like activities in seminal plasma and spermatozoa

Reactive oxygen species (ROS) can be detected in the semen of 40% of infertile men, whereas none is detected in semen from normal men. The ROS detected in semen are a reflection of the imbalance between ROS production and degradation. The aim of the present study was to determine whether a lowered scavenging capacity or an increased production of ROS was responsible for the ROS detected in semen samples from infertile men. Two activities were investigated: (1) catalase-like activity, which is responsible for the degradation of H₂O₂, and (2) superoxide dismutase-like (SOD-like) activity which is responsible for the degradation of O₂-_-. Catalase-like and SOD-like activities were found in whole seminal plasma, in dialyzed seminal plasma (> 12 kD), in an ultrafiltrate of seminal plasma (< 5 kD) and in spermatozoa. There was no significant difference in the SOD-like activities measured in spermatozoa, or in seminal plasma (whole or fractionated) from samples that did or did not produce ROS. SOD-like activity originated mostly from the high molecular weight components of seminal plasma. However, the catalase-like activity of whole seminal plasma and of spermatozoa was significantly greater ( P = 0.01) in those samples that produced ROS as compared to those that did not. The catalase-like activity in dialyzed seminal plasma, and an ultrafiltrate of seminal plasma from semen samples that did or did not produce ROS were not statistically different. The catalase-like activity of the seminal plasma originated equally from high and low molecular weight components. In conclusion, the data suggest that the ROS detected in the semen of infertile patients are likely due to increased ROS production rather than to decreased ROS scavenging capacity.     

Determination of fatty acid profile in ram spermatozoa and seminal plasma

Fatty acids are important in male reproductive function because they are associated with membrane fluidity, acrosome reaction, sperm motility and viability, but limited information exists about the fatty acid profile of ram semen. Our aim was to determine the fatty acid composition in ram spermatozoa and seminal plasma. Sixty ejaculates were obtained from three ram (20 ejaculates/ram) using artificial vagina. Ram spermatozoa (RS) and seminal plasma (SP) were separated using centrifugation, and the fatty acids were analysed by gas chromatography. Total lipids obtained in ram spermatozoa were 1.8% and 1.6% in seminal plasma. Saturated fatty acid (SFA) was proportionally major in SP (66.6%) that RS (49.9%). The highest proportions of SFA corresponded to C4:0 (RS = 16.3% and SP = 28.8%) and C16:0 (RS = 16.3% and PS = 20%). The most important unsaturated fatty acid (UFA) was docosahexaenoic acid (DHA), 44.9% in RS and 31.5% in SP. The profile of fatty acid and their proportions showed differences between spermatozoa and seminal plasma.     

Sperm motility inhibitor from human seminal plasma: presence of a precursor molecule in seminal vesicle fluid and its molecular processing after ejaculation

Human seminal plasma contains a protein factor that has the capacity to inhibit the movement of demembranated and intact spermatozoa. This factor 'seminal plasma motility inhibitor' (SPMI) has been shown to originate exclusively from the seminal vesicles. The present results demonstrate that the biological activity of SPMI in semen decreases rapidly from 1000 U/d, immediately after ejaculation, to 220 U/ml 2 h later. Immunoblots of seminal plasma proteins probed with an antibody against human SPMI, revealed the rapid processing of a predominant 52 kDa SPMI antigen, present in the seminal vesicle secretions. This precursor was degraded initially into intermediate molecular mass fragments of 25–40 kDa, and subsequently into smaller fragments of 17–21 kDa. When seminal vesicle fluid was mixed with prostatic secretions (3: 1 v/v), proteases present in prostatic secretions were shown to be responsible for processing of the SPMI precursor. Addition of protease inhibitors such as phenylmethylsulphonyl fluoride (PMSF, 5 mM), benzamidine (100 mM) or ethylenediaminetetraacetic acid (EDTA, 5 mM) to the mixture of seminal vesicle and prostate secretions partially prevented the loss of activity of SPMI by 54%, 27% and 9%, respectively. However, the simultaneous addition of PMSF and benzamidine conferred almost total stability to the SPMI precursor activity. These results demonstrate that SPMI exists as a predominant 52 kDa precursor form in the seminal vesicles and is processed rapidly after ejaculation into less active, lower molecular mass forms by one or more serine proteases and/or metallo-proteases of prostatic origin which are present in liquefied semen.     

Effect of spermatic vein ligation on seminal total antioxidant capacity in terms of varicocele grading

We aimed to assess the effect of spermatic vein ligation on seminal total antioxidant capacity (TAC) in patients with varicocele. Twenty infertile male patients with varicocele and 20 normal fertile men (control group) were included in the study. All the male patients were diagnosed with primary infertility and varicocele. The patients with varicocele were divided into two groups as nonpalpable (GI) (eight patients) and palpable (GII-III) (12 patients) varicocele groups. All the patients underwent microsurgical spermatic vein ligation. Seminal TAC levels and sperm parameters were evaluated in all the patients. Preoperative sperm count, sperm motility, sperm morphology and seminal TAC levels with equivalent figures 3-6 months after spermatic vein ligation and the same values of the control group were compared. There was a statistically significant increase in the total seminal antioxidant capacity level after spermatic vein ligation, and there was a statistically significant increase in the sperm count, sperm motility and spermatozoa with normal morphology. However, evaluation of the patients for varicocele grade showed a statistically significant increase in the TAC level only in the GII-III varicocele group. Spermatic vein ligation can improve the total seminal antioxidant capacity levels especially in patients with middle and high grade varicocele.     

High seminal sialic acid concentrations in patients with severe teratozoospermia.

Seminal plasma and sperm-bound sialic acid (SA) concentrations were evaluated in patients with severe teratozoospermia (less than 5% morphologically normal sperm) and correlated with values of a control group with greater than 20% morphologically normal sperm. The SA concentrations both in seminal plasma and on sperm were significantly higher in teratozoospermia, but the ratio of sperm-bound SA to seminal plasma SA remained virtually the same. The causes and consequences of high SA in these patients need further study.     

Evaluation of a commercially available kit for the colorimetric determination of zinc in human seminal plasma

A kit from Wako Pure Chemical Industries for colorimetric determination of zinc has been evaluated for its possible use in the determination of zinc in human seminal plasma. The within-assay variation for 15 replicates of each of two seminal plasma samples having zinc concentrations (mM) of 0.43 +/- 0.025 and 6.06 +/- 0.125 (mean +/- SD) was 5.7% and 2.1%, respectively. The between-assay variation after analysis of 15 replicates of a seminal plasma sample (zinc conc. 5.6 mM) on different days was 2.3%. No interference from other metal ions present in seminal plasma was observed. The average % recovery of zinc added to seminal plasma was 102.7 +/- 1.77 (mean +/- SD). A close correlation (r = 0.996, n = 105) was found between the levels of zinc determined by the colorimetric method and that determined by atomic absorption spectrophotometry as reference method. It is concluded that the present colorimetric method, which is fast, sensitive and linear over the entire concentration range of zinc present in human seminal plasma, can be recommended for use in semen analysis laboratories.     

Varicocelectomy reduces reactive oxygen species levels and increases antioxidant activity of seminal plasma from infertile men with varicocele

Several theories have been advanced to explain the mechanisms by which varicocele impairs male fertility. These theories include scrotal hyperthermia, retrograde flow of adrenal or renal metabolites, Leydig cell dysfunction and hypoxia. Varicocele is reported to be associated with elevated reactive oxygen species (ROS) production in spermatozoa and diminished seminal plasma antioxidant activity. The aim of this study was to investigate whether surgical correction of varicocele might reduce ROS or increase the antioxidant capacity of seminal plasma from infertile patients with varicocele. The study group consisted of 68 infertile males, selected from patients scheduled for varicocelectomy at Cairo University Hospital during the year 1999. Seminal plasma levels of two ROS [malondialdehyde (MDA), hydrogen peroxide (H2O2)] and one ROS radical [nitric oxide (NO)] were estimated as well as six antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), vitamin C (Vit C), vitamin E (Vit E), albumin) on the day prior to varicocelectomy. For comparison, the same parameters were measured again 3 and 6 months post-operatively. A statistically significant reduction in the 3 month post-operative levels of MDA, H2O2 and NO was observed when compared with the pre-operative values. A further significant reduction took place during the following 3 months. Four of the six antioxidants tested (SOD, CAT, GPx, and Vit C) showed a significant increase in seminal levels when comparing 3-month post-operative with pre-operative values. A further significant increase of the four antioxidant levels took place during the following 3 months. No significant change in the level of seminal plasma albumen took place during the first 3 months after varicocelectomy, however, a significant increase was noted during the next 3 months. In contrast to other antioxidants, seminal plasma levels of Vit E showed a significant decrease when comparing 3-month post-operative with pre-operative values. A further significant decrease took place during the following 3 months. It is concluded that varicocelectomy reduces ROS levels and increases antioxidant activity of seminal plasma from infertile men with varicocele.