Nitric Oxide Synthase and Xanthine Oxidase Activities in the Spermatic Vein of Patients with Varicocele: A Potential Role for Nitric Oxide and Peroxynitrite in Sperm Dysfunction

Protective effects of alpha-lipoic acid and alagebrium chloride against testicular dysfunction induced by varicocele and advanced glycation end (AGE) - Rich diet in a rat mode

Heat stress from varicocele can heighten oxidative stress in the testes, impacting sperm function and male fertility. Antioxidant therapy is explored as a remedy for varicocele, while dietary factors like processed foods, sugar, and saturated fats correlate with male infertility. Advanced glycation end products (AGEs), generated through glycation processes, can provoke oxidative stress, inflammation, and adverse health consequences. Alpha-lipoic acid (ALA), a versatile antioxidant, may alleviate oxidative stress and counteract the impact of AGEs, potentially by enhancing glucose reabsorption. Alagebrium chloride (ALT711), an anti-AGE compound, exhibits promise in cardiovascular disease by disrupting AGE cross-links. This study investigates the effects of ALA and ALT-711 on testicular function in varicocele and AGEs animal models. Both AGE and varicocele were found to alter the natural trends, leading to abnormal patterns in sperm parameters, testicular functional tests, as well as the expression of CML, RAGE, and TNF-α proteins. However, the administration of ALA or ALT711 helped mitigate these effects. While ALA demonstrated a slightly greater overall benefit compared to ALT, the difference was not statistically significant.

Reactive Nitrogen Species and Male Reproduction: Physiological and Pathological Aspects

Reactive nitrogen species (RNS), like reactive oxygen species (ROS), are useful for sustaining reproductive processes such as cell signaling, the regulation of hormonal biosynthesis, sperm capacitation, hyperactivation, and acrosome reaction. However, endogenous levels of RNS beyond physiological limits can impair fertility by disrupting testicular functions, reducing gonadotropin production, and compromising semen quality. Excessive RNS levels cause a variety of abnormalities in germ cells and gametes, particularly in the membranes and deoxyribonucleic acid (DNA), and severely impair the maturation and fertilization processes. Cell fragmentation and developmental blockage, usually at the two-cell stage, are also connected with imbalanced redox status of the embryo during its early developmental stage. Since high RNS levels are closely linked to male infertility and conventional semen analyses are not reliable predictors of the assisted reproductive technology (ART) outcomes for such infertility cases, it is critical to develop novel ways of assessing and treating oxidative and/or nitrosative stress-mediated male infertility. This review aims to explicate the physiological and pathological roles of RNS and their relationship with male reproduction.

Reactive oxygen, nitrogen, and sulfur species in human male fertility. A crossroad of cellular signaling and pathology

Infertility is a significant global health problem that currently affects one of six couples in reproductive age. The quality of male reproductive cells dramatically decreased over the last years and almost every aspect of modern life additionally worsen sperm functional parameters that consequently markedly increase male infertility. This clearly points out the importance of finding a new approach to treat male infertility. Redox signaling mediated by reactive oxygen, nitrogen and sulfur species (ROS, RNS, and RSS respectively), has appeared important for sperm reproductive function. Present review summarizes the current knowledge of ROS, RNS, and RSS in male reproductive biology and identifies potential targets for development of novel pharmacological and therapeutic approaches for male infertility by targeted therapeutic modulation of redox signaling.

Mass Spectrometry Reveals New Insights into the Production of Superoxide Anions and 4-Hydroxynonenal Adducted Proteins in Human Sperm

The free-radical theory of male infertility suggests that reactive oxygen species produced by the spermatozoa themselves are a leading cause of sperm dysfunction, including loss of sperm motility. However, the field is overshadowed on several fronts, primarily because: i) the probes used to measure reactive oxygen species (ROS) are imprecise; and ii) many reports suggesting that oxygen radicals are detrimental to sperm function add an exogenous source of ROS. Herein, a more reliable approach to measure superoxide anion production by human spermatozoa based on MS analysis is used. Furthermore, the formation of the lipid-peroxidation product 4-hydroxynonenal (4-HNE) during in vitro incubation using proteomics is also investigated. The data demonstrate that neither superoxide anion nor other free radicals that cause 4-HNE production are related to the loss of sperm motility during incubation. Interestingly, it appears that many of the 4-HNE adducted proteins, found within spermatozoa, originate from the prostate. A quantitative SWATH analysis demonstrate that these proteins transiently bind to sperm and are then shed during in vitro incubation. These proteomics-based findings propose a revised understanding of oxidative stress within the male reproductive tract.

Dilating Vascular Diseases: Pathophysiology and Clinical Aspects

Atherosclerotic disease of the vessels is a significant problem affecting mortality and morbidity all over the world. However, dilatation of the vessels either in the arterial system or in the venous territory is another vessel disease. Varicocele, pelvic, and peripheral varicose veins and hemorrhoids are aneurysms of the venous vascular regions and have been defined as dilating venous disease, recently. Coronary artery ectasia, intracranial aneurysm, and abdominal aortic aneurysm are examples of arterial dilating vascular diseases. Mostly, they have been defined as variants of atherosclerosis. Although there are some similarities in terms of pathogenesis, they are distinct from atherosclerotic disease of the vessels. In addition, pathophysiological and histological similarities and clinical coexistence of these diseases have been demonstrated both in the arterial and in the venous system. This situation underlies the thought that dilatation of the vessels in any vascular territory should be considered as a systemic vessel wall disease rather than being a local disease of any vessel. These patients should be evaluated for other dilating vascular diseases in a systematic manner.

Significant alterations of 6-keto prostaglandin F1a and NO levels in spermatic vein plexus patients with varicocele

To investigate the level variation of correlative factors between the spermatic vein plexus and peripheral blood in patients with varicocele, a total of 22 patients diagnosed with varicocele were enrolled in the study. All patients were performed a testicular artery-sparing microsurgical varicocelectomy. During the operation, a blood sample from the left spermatic vein plexus and a peripheral blood sample were collected. A radioimmunoassay was used to determine the 6-keto prostaglandin F1a (6-keto-PGF1a ). A colorimetric method was performed to determine the NO. The enzyme immunoassay method was used to determine the creatinine, urea nitrogen, adrenaline, noradrenaline, dopamine and 5-HT. The mean age of all patients was 29.3 ± 7.8 years. Compared with the level of 6-keto-PGF1a and NO in the peripheral blood, 6-keto-PGF1a and NO were significantly increased in left spermatic vein plexus (347.3 (230.8-415.1) versus 99.7 (80.4-119.9) pg/ml and 192.3 ± 178.5 versus 107.1 ± 73.6 μmol/L, p < .05). There were no differences in the level of creatinine, urea nitrogen, adrenaline, noradrenaline, dopamine and 5-HT between the peripheral blood and left spermatic vein plexus (p > .05). The 6-keto-PGF1a and NO concentrations in left spermatic vein plexus were significantly higher than that in peripheral blood patients with varicocele.

Genetics and epigenetics of varicocele pathophysiology: an overview

Varicocele is found in approximately 20% of adults and adolescents and in 19-41% of men seeking treatment for infertility. It is associated with a decrease in sperm count as well as sperm motility and morphology. The currently accepted description of the pathophysiology of varicocele does not explain all its clinical manifestations; therefore, other factors such as genetic and epigenetic changes, associated with the environment, might be involved in causing infertility and decrease in sperm quality. It has been reported that the varicocele-induced deterioration of testicular function is progressive and interferes with fertility; hence, early and efficient assessment of the genetic manifestations in patients would be important for developing future medical interventions. Chromosomal disorders, mutations, polymorphisms, changes in gene expression, and epigenetic changes have all been reported to be associated with varicocele. Several studies are underway to unravel the genetic basis of this disease, as it is important to understand the origin and the aggravating factors to ensure appropriate guidance and intervention. Here, we review the available literature regarding the genetic and epigenetic changes associated with varicocele, and how these alterations are related to the different clinical manifestations of the disease.

Dilating venous disease: Pathophysiology and a systematic aspect to different vascular territories

Venous disease is a common but overlooked clinical problem and is an important mortality and morbidity factor depending on the effected vascular territory. Different contributing factors play role on the clinical manifestation of the disease. Peripheral varices of lower extremities, hemorrhoids, varicoceles, pelvic varicose veins are the vasculopathy of veins running toward heart but against gravity. We hypothesize that all these clinical entities share common pathophysiologic steps in terms of vascular wall remodeling and vessel wall damage. A systematic approaches to both arterial and venous dilating disease in further studies and research would increase our understanding on the pathophysiology of dilating vascular disease and would provoke to find out new treatment modalities. Varicose remodeling of veins occurs by a complex interplay of various factors including both physical forces and extracellular matrix remodeling mechanisms. This article focuses on the systematic aspects of dilating venous disease with a focus on pathophysiology under the term of "Dilating Venous Disease".

Comparison of Before and After Varicocelectomy Levels of Trace Elements, Nitric Oxide, Asymmetric Dimethylarginine and Malondialdehyde in the Seminal Plasma and Peripheral and Spermatic Veins

Increased oxidative damage has been suggested to play an important role in the spermatogenesis and sperm function changes in patients with varicocele. However, changes in levels of nitric oxide (NO), asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), iron (Fe), zinc (Zn) and copper (Cu) in blood and seminal plasma, and semen quality, are unknown. The aim of this study was to investigate the NO, ADMA, Fe, Cu, Zn and MDA levels from seminal plasma and peripheral and spermatic vein blood samples of patients with varicocele before and after varicocelectomy. In this before and after comparative study, 29 consecutive patients attending a training hospital in Tekirdag, Turkey, were recruited. MDA and NO levels were determined by spectrophotometric methods. The levels of ADMA were determined by enzyme-linked immunosorbent assay method. Trace element level was determined by atomic absorption spectrophotometric method. The levels of MDA in the seminal plasma and peripheral and spermatic vein samples were observed to decrease significantly in the comparison of before and after phases of the study group (p = 0.022, p = 0.001 and p = 0.034, respectively). Also, the levels of NO in the seminal plasma and spermatic vein samples decreased significantly in the comparison of before and after phases of the study group (p = 0.025 and p = 0.001, respectively), while the levels of ADMA in seminal plasma and spermatic vein samples increased significantly in the comparison of before and after phases of the study group (p = 0.003 and p = 0.001, respectively). There were no significant differences in the levels of trace elements and sperm count (p > 0.05). Oxidative stress is significantly higher in the spermatic vein and seminal plasma samples of patients with varicocele before varicocelectomy. In conclusion, these events may be evaluated accordingly for the potentially beneficial treatment methods.

Regulatory mechanism of protein metabolic pathway during the differentiation process of chicken male germ cell

We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro.

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.

Characterisation of a subpopulation of sperm with massive nuclear damage, as recognised with the sperm chromatin dispersion test

Assessment of human sperm DNA fragmentation by the sperm chromatin dispersion (SCD) test is based on the detection of haloes of spreading DNA loops after sequential DNA denaturing and protamine removal. After the SCD test, sperm without DNA fragmentation show chromatin haloes emerging from the central nuclear core, while sperm containing fragmented DNA present small or no haloes. The nuclear degraded sperm are recognised as a differentiated category within the sperm with fragmented DNA, whose cores appear irregularly and/or faintly stained. This subpopulation is more prevalent in patients with varicocele. Protein staining with 2.7-dibrom-4-hydroxy-mercury-fluorescein demonstrated that degraded sperm intensely lose nuclear core proteins after the SCD processing. Moreover, degraded sperm are 65% more faintly labelled for DNA breaks after in situ nick translation (ISNT) on average, due to extensive DNA loss. A two-dimensional comet assay under sequential neutral and alkaline conditions demonstrated that degraded sperm contain both massive double- and single-strand DNA breaks. The degraded sperm appear as a subpopulation with stronger nuclear damage, affecting both DNA and protein fractions, possibly due to intense intratesticular oxidative stress, what could explain its higher proportion in patients with varicocele.

Role of reactive nitrogen species in male infertility

Reactive nitrogen species (RNS) is a subset of free oxygen radicals called reactive oxygen species (ROS). Physiological levels of ROS are necessary to maintain the reproductive functions such as cell signaling, tight junction regulation, production of hormones, capacitation, acrosomal reaction, sperm motility, and zona pellucida binding. However, an excess of RNS can adversely affect reproductive potential by causing testicular dysfunction, decreased gonadotropin secretion, and abnormal semen parameters. Because such levels of RNS have been demonstrated in males with fertility problems and routine semen analysis has not been able to accurately predict IVF outcomes, it is imperative that novel strategies be developed in order to both assess and treat oxidative stress. This article describes both physiological and pathological roles of this unique subset of ROS.

Insight into oxidative stress in varicocele-associated male infertility: part 2

Varicocele, the leading cause of male infertility, can impair spermatogenesis through several pathophysiological mechanisms. Of these, current evidence suggests that oxidative stress is the central element contributing to infertility in men with varicocele, to which the testis responds by way of heat stress, ischaemia or production of vasodilators, such as nitric oxide. Surgical varicocele repair (varicocelectomy) is beneficial not only for alleviating oxidative stress-associated infertility, but also for preventing and protecting against the progressive character of varicocele and its consequent upregulations of systemic oxidative stress. However, antioxidant therapy in infertile men with surgically treated and those with untreated varicocele is poorly studied, and well-designed trials are needed.

Insight into oxidative stress in varicocele-associated male infertility: part 1

Varicocele is recognized as the leading cause of male infertility because it can impair spermatogenesis through several distinct pathophysiological mechanisms. Current evidence supports oxidative stress as a key element in the pathophysiology of varicocele-related infertility, although these mechanisms have not yet been fully described. Measurement of the reactive oxygen species and other markers of oxidative stress, including the levels of the antioxidant enzymes catalase and superoxide dismutase, can provide valuable information on the extent of oxidative stress and might guide therapeutic management strategies. The testis can respond to varicocele-associated cell stressors, such as heat stress, ischaemia or production of vasodilators (for example, nitric oxide) at the expense of the generation of excessive reactive oxygen species. These responses have their own implications in exacerbating the underlying oxidative stress and on the subsequent infertility.

Comparison of before and after varicocelectomy levels of nitric oxide in seminal fluid of infertile men

Background

Since nitric oxide (NO) has an oxidant activity, lower levels following a varicocelectomy may result in better functioning sperm, improved semen quality and consequently higher fertility rates. However, this procedure should be examined in more detail.

Objectives

Accordingly, this study was performed to compare the before and after varicocelectomy levels of NO in the seminal fluid of infertile men.

Patients and Methods

In this before and after comparative study, 20 consecutive patients attending a training hospital in Tehran, Iran were recruited. All of these men had primary or secondary infertility accompanied with a varicocele. A semen sample was collected from the men in two phases, first before their varicocelectomy and two months after their operation.

Results

NO levels differed significantly across the study and the mean (± standard deviation) levels of NO in the patients were 30.59 ± 10.35 µM/L and 21.48 ± 32.14 µM/L in the before and after phases of the study, respectively (P = 0.009).

Conclusions

According to the results obtained in this study, it may be concluded that in future, levels of NO should be taken into consideration together with other parameters for the evaluation of patients who are affected by varicoceles, to determine probable therapeutic responses.

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.

Relationship between varicocele and sperm DNA damage and the effect of varicocele repair: a meta-analysis

Varicocele, a cause of male infertility, occurs in nearly 40% of infertile males. It has been postulated that varicoceles may cause sperm DNA damage. Sperm DNA integrity has been recognized as one of the important determinants of normal fertilization and embryo growth in natural and assisted conception. Eighty-three human studies were identified after an extensive literature search involving the role of varicoceles in sperm DNA damage. Of the 83 studies, 12 were selected that measured similar types of reactive sperm DNA damage. Seven studies determined the damage of sperm DNA in varicocele-associated patients and six studies evaluated the efficacy of varicocelectomy. One study was a duplicate because both outcomes were included. Data were analysed using RevMan software. The overall estimate showed that patients with varicoceles have significantly higher sperm DNA damage than controls, with a mean difference of 9.84% (95% CI 9.19 to 10.49; P<0.00001). A varicocelectomy can improve sperm DNA integrity, with a mean difference of -3.37% (95% CI -4.09 to -2.65; P<0.00001). In conclusion, there is increased sperm DNA damage in patients with varicoceles and varicocelectomy may be a possible treatment; however, more studies with appropriate controls are needed to confirm this finding. A varicocele is an important cause of male infertility and occurs in nearly 40% of infertile males. The recent understanding of the effect of varicoceles in male reproduction has led some researchers to postulate varicoceles as the possible cause of sperm DNA damage. Eighty-three human studies were identified after an extensive literature search involving the role of varicoceles in sperm DNA damage. Of the 83 studies, 12 were selected that measured similar types of reactive sperm DNA damage by a similar method. Seven studies determined the damage of sperm DNA in varicocele-associated patients and six studies evaluated the efficacy of varicocelectomy. One study was a duplicate because both outcomes were included. The data were then entered in the RevMan software for analysis. The overall estimate showed that patients with varicoceles have significantly higher sperm DNA damage than controls, with a mean difference of 9.84% (95% CI 9.19 to 10.49; P<0.00001). A varicocelectomy can improve sperm DNA integrity, with a mean difference of -3.37% (95% CI -4.09 to -2.65; P<0.00001). Based on the results, it can be concluded that there is increased sperm DNA damage in patients with varicoceles and that varicocelectomy may be a possible treatment; however, more studies with appropriate controls are needed to confirm this finding.

Simultaneous determination in situ of DNA fragmentation and 8-oxoguanine in human sperm

Deoxyribonucleic acid fragmentation and oxidative DNA damage were simultaneously determined in the same sperm cell, incubating with an 8-oxoguanine DNA probe on human spermatozoa processed by the sperm chromatin dispersion test. The assay was validated by incubation with agents that induce DNA fragmentation with or without oxidative base damage. In all samples examined, increased levels of 8-oxoguanine were present only in those spermatozoa with fragmented DNA, suggesting a link between both DNA damage types.

Varicocele and infertility: why a prevention?

The varicocele is the abnormal dilation of the veins of the pampiniform plexus, resulting from an altered venous drainage, and it is considered one of the main causes of male infertility. In this paper we review the most recent observations on the histological, endocrinological, biochemical and clinical alterations reported in adolescents with left idiopathic varicocele. Data indicate that varicocele progressively impairs the reproductive function of the testis. Treatment could improve a number of such damages.

Seminal reactive oxygen species-antioxidant relationship in fertile males with and without varicocele

The aim of this study was to assess seminal reactive oxygen species (ROS)-antioxidants relationship in fertile and infertile men with and without varicocele. One hundred and seventy six males were studied; fertile healthy volunteers (n = 45), fertile men with varicocele (n = 45), infertile oligoasthenozoospermia (OA, n = 44) without varicocele and infertile OA with varicocele (n = 42). In their seminal plasma, two ROS parameters (malondialdehyde, hydrogen peroxide) and five antioxidants (superoxide dismutase, catalase, glutathione peroxidase, vitaminE, vitaminC) were estimated. Compared with fertile healthy men, in all other studied groups, estimated seminal ROS were significantly higher and estimated antioxidants were significantly lower. Infertile men with varicocele showed the same relationship as infertile men without varicocele. Sperm concentration, total sperm motility as well as sperm normal forms were negatively correlated with seminal malondialdehyde and were positively correlated with vitaminC. It is concluded that varicocele has an oxidative stress (OS) in fertile normozoospermic bearing conditions. This may allow understanding that, within men with varicocele, there is a threshold value of OS over which male fertility may be impaired.

Genetic polymorphisms in glutathione S-transferase T1 affect the surgical outcome of varicocelectomies in infertile patients

Glutathione S-transferases (GSTs), superoxide dismutase 2 (SOD2) and NAD(P)H:quinone oxidoreductase 1 (NQO1) are anti-oxidant enzyme genes. Polymorphisms of GSTs, SOD2 and NQO1 have been reported to influence individual susceptibility to various diseases. In an earlier study, we obtained preliminary findings that a subset of glutathione S-transferase T1 (GSTT1)-wt patients with varicocele may exhibit good response to varicocelectomy. In this study, we extended the earlier study to determine the distribution of genotype of each gene in the infertile population and to evaluate whether polymorphism of these genes affects the results of surgical treatment of varicocele. We analyzed 72 infertile varicocele patients, 202 infertile patients without varicocele and 101 male controls. Genotypes of GSTs were determined by polymerase chain reaction (PCR). Genotyping of SOD2 and NQO1 was performed using the PCR-restriction fragment length polymorphism (PCR-RFLP) method. A significantly better response to varicocelectomy was found in patients with the GSTT1-wt genotype (63.2%) and NQO1-Ser/Ser genotype (80.0%) than in those with GSTT1-null genotype (35.3%) and NQO1-Pro/Pro or NQO1-Pro/Ser genotype (45.2%), respectively. The frequencies of glutathione S-transferase M1/T1, SOD2 and NQO1 genotypes did not differ significantly among the varicocele patients, idiopathic infertile patients and male controls. GSTT1 genotype is associated with improvement of semen parameters after varicocelectomy. As the number of patients with NQO1-Ser/Ser genotype was not sufficient to reach definite conclusions, the association of NQO1 genotype with varicocelectomy requires further investigation.

The role of varicocele repair in the new era of assisted reproductive technology

Infertility affects 10-15% of couples who are trying to conceive, and half of the cases are due to male infertility. Intracytoplasmic sperm injection is increasingly being used to overcome multiple sperm deficiencies. Due to its effectiveness, some have proposed ICSI as a solution for all cases of male infertility, regardless of the cause. Hence, even men with potentially treatable causes of infertility have sought the aid of assisted reproductive technology, rather than undergo specific therapies to treat their infertility. Varicoceles are the most frequent physical finding in infertile men; indeed, they may be responsible for nearly one-third of cases of male infertility. Varicocele management, however, has always been a controversial issue because very few randomized, controlled studies have been performed to examine varicocelectomy as an infertility treatment. Significant evidence suggests that varicoceles have a harmful effect on the testis and that varicocelectomy can not only prevent progressive decline in testicular function but also reverse the damage. However, the degree to which varicocele repair improves pregnancy rates and the success of assisted reproductive technology remains controversial.

Clinical relevance of oxidative stress in male factor infertility: an update

Male factor has been considered a major contributory factor to infertility. Along with the conventional causes for male infertility such as varicocele, cryptorchidism, infections, obstructive lesions, cystic fibrosis, trauma, and tumors, a new, yet important cause has been identified: oxidative stress. Oxidative stress (OS) is a result of the imbalance between reactive oxygen species (ROS) and antioxidants in the body, which can lead to sperm damage, deformity and eventually male infertility. This involves peroxidative damage to sperm membrane and DNA fragmentation at both nuclear and mitochondrial levels. OS has been implicated as the major etiological factor leading to sperm DNA damage. OS-induced DNA damage can lead to abnormalities in the offspring including childhood cancer and achondroplasia. In this article, we discuss the need of ROS in normal sperm physiology, the mechanism of production of ROS and its pathophysiology in relation to male reproductive system. The benefits of incorporating antioxidants in clinical and experimental settings have been enumerated. We also highlight the emerging concept of utilizing OS as a method of contraception and the potential problems associated with it.

Nitric oxide produced in the testis is involved in dilatation of the internal spermatic vein that compromises spermatogenesis in infertile men with varicocele

OBJECTIVE

To determine the concentration of nitric oxide (NO) and the location and change in the expression of NO synthase (NOS) isoforms in the testes of subfertile men with varicocele, and to compare the NO concentration or NOS expression with clinical variables, to determine the role of NO on the pathophysiology of varicocele.

PATIENTS AND METHODS

In all, 27 men who had a left varicocelectomy and five with 'normal' spermatogenesis (controls) who had scrotal surgery for other reasons were enrolled. Intratesticular fluid was taken from the men and the NO concentration determined colorimetrically. The expression and location of NOS isoforms were examined by Western blotting and immunohistochemistry, using testicular biopsy specimens, and NADPH-diaphorase (NADPH-d) staining used to identify NO-producing cells. The relationship between the NO concentration and the expression of NOS isoforms or clinicopathological variables was investigated.

RESULTS

In testes with grade 2 and 3 varicoceles there were significant increases in the concentration of NO or the expression of inducible NOS. There was no change in the expressions of endothelial NOS, which is located in vascular endothelial cells, while NADPH-d activity was mainly located in these cells. The concentration of NO was significantly correlated with the maximum and total vein diameter (both P<0.01). In patients aged>35 years, the concentration of NO significantly correlated with a deterioration in total motile sperm count (P<0.05).

CONCLUSIONS

Increased production of NO in the testis is involved in the enlargement of varicocele and indirectly deteriorates spermatogenesis.

Decreased protein tyrosine phosphorylation and membrane fluidity in spermatozoa from infertile men with varicocele

Varicocele is a prevalent pathology among infertile men. The mechanisms linking this condition to infertility, however, are poorly understood. Our previous work showed a relationship between sperm functional quality and the ability of spermatozoa to respond to capacitating conditions with increased membrane fluidity and protein tyrosine phosphorylation. Given the reported association between varicocele, oxidative stress, and sperm dysfunction, we hypothesized that spermatozoa from infertile patients with varicocele might have a combined defect at the level of membrane fluidity and protein tyrosine phosphorylation. Semen samples from infertile patients with and without grade II/III left varicocele were evaluated for motion parameters (computer-assisted semen analysis [CASA]), hyperactivation (CASA), incidence and intensity of protein tyrosine phosphorylation (phosphotyrosine immunofluorescence and western blotting), and membrane fluidity (Laurdan fluorometry), before and after a capacitating incubation (6 hr at 37 degrees C in Ham's F10/BSA, 5% CO(2)). Spermatozoa from varicocele samples presented a decreased response to the capacitating challenge, showing significantly lower motility, hyperactivation, incidence and intensity of tyrosine phosphorylation, and membrane fluidity. The findings reported in this article indicate that the sperm dysfunction associated to infertile varicocele coexists with decreased sperm plasma membrane fluidity and tyrosine phosphorylation. These deficiencies represent potential new pathophysiological mechanisms underlying varicocele-related infertility.

Effect of age and grade on surgery for patients with varicocele

OBJECTIVES

To assess the seminal characteristics, hormonal levels, and pathologic findings in patients of various age groups with varicocele before and after ligation to establish the presence of an aging effect in patients with varicocele on those characteristics.

METHODS

The records were retrospectively evaluated for 70 infertile patients with azoospermia or oligospermia who underwent microsurgical left inguinal varicocele ligation. The mean +/- SD patient age was 33.9 +/- 5.5 years. Left varicocele was detected in 70 patients. We divided our patients into three groups according to age: group 1, 20 to 29 years old (n = 17); group 2, 30 to 39 years old (n = 41); and group 3, older than 40 years (n = 12).

RESULTS

Before ligation, no significant differences were seen among the three groups in luteinizing hormonal level, prolactin level, estradiol level, right testicular volume, semen volume, and sperm concentration and sperm motility. Significant differences were seen in the follicle-stimulating hormonal level, testosterone level, and left testicular volume. After ligation, even in group 3, the sperm concentration and motility increased from 6.38 +/- 5.47 to 13.07 +/- 9.05 million/mL (P = 0.042) and from 28.42% +/- 23.22% to 39.92% +/- 22.06%, respectively. No significantly greater degree of improvement in semen characteristics was observed between grade II and grade III after varicocele ligation.

CONCLUSIONS

The results of our study have shown that age is not a significant predictive factor of improvement in semen characteristics before ligation. It is reasonable to perform ligation to improve the semen characteristics in patients older than 40 years old.

Increased expression of Leydig cell haem oxygenase-1 preserves spermatogenesis in varicocele

BACKGROUND

Oxidative stress is involved in the pathogenesis of testicular disorders. Haem oxygenase-1 (HO-1) plays an important cytoprotective role against oxidative stress. We investigated the presence of oxidative stress, represented by generation of 4-hydroxy-2-nonenal (4-HNE)-modified proteins, and expression of HO-1 in varicocele testes of human.

METHODS

Thirty testicular biopsies from patients with left varicocele and 10 from patients with normal spermatogenesis were included. Generation of 4-HNE-modified proteins was examined as a marker of oxidative stress. Expression of HO-1 was assessed by western blotting and immunohistochemistry. The expression was compared with clinico-pathological parameters.

RESULTS

Increased generation of 4-HNE-modified proteins was observed in varicocele testes. HO-1 expression was significantly correlated with varicocele grade (P < 0.01 in grade 2 and 3 compared to control) and expression of 4-HNE-modified proteins (r = 0.508, P < 0.01). The immunoreactivity was increased in Leydig cells in varicocele testes. There were significant correlations between age, total motile sperm count, Johnsen's mean score and HO-1:4-HNE-modified protein ratio (r = 0.206, 0.405 and 0.408, P = 0.027, 0.027 and 0.025 respectively).

CONCLUSIONS

In testes with varicocele, there are increases in 4-HNE-modified proteins, suggesting that oxidative stress is present. Increased HO-1 expression, mainly in Leydig cells, is considered to protect the cells against oxidative stresses in varicocele testes.

Deletions in L-type calcium channel α1 subunit testicular transcripts correlate with testicular cadmium and apoptosis in infertile men with varicoceles

OBJECTIVE

To identify and understand predictors of successful varicocelectomy.

DESIGN

Examination of testicular L-type voltage-dependent calcium channel (L-VDCC) mRNAs and proteins in testis biopsies and comparison of presence and absence of various mRNAs with testicular cadmium levels, with apoptosis, and with sperm count change after varicocelectomy.

SETTING

University clinical urology practice and research laboratories.

PATIENT(S)

Infertile men with varicocele (left varicocele only, n = 18; bilateral varicoceles, n = 26) and controls (men with obstructive azoospermia undergoing testicular sperm extraction before intracytoplasmic sperm injection; n = 7).

INTERVENTION(S)

Left testis biopsies by percutaneous needle aspiration biopsy. Varicocele repair by subinguinal approach.

MAIN OUTCOME MEASURE(S)

Calcium channel mRNA sequence by reverse transcription-polymerase chain reaction and amplicon analysis; calcium channel protein distribution by immunocytochemistry; cadmium levels by atomic absorption and apoptosis by deoxynucleotidyl transferase labeling; and sperm counts in the ejaculate before and after varicocelectomy.

RESULT(S)

Calcium channel mRNAs are polymorphic in human testis biopsies from different men. Proteins from sequence-deleted exons 7 and/or 8 localize to germ cell membranes. Expression of undeleted L-type calcium channel mRNAs correlates with normal testes cadmium and increased sperm count after varicocelectomy. Apoptosis is lower in such cases.

CONCLUSION(S)

Expression of normal testicular L-VDCC sequence in exons 7-8 predicts postvaricocelectomy sperm count increase. Deletions may alter calcium channel function and affect testicular cadmium and apoptosis.

Interstitial telomeric DNA sequences of Chinese hamster cells are hypersensitive to nitric oxide damage, and DNA-PKcs has a specific local role in its repair

The DNA breakage detection-fluorescence in situ hybridization (DBD-FISH) procedure was used to analyze DNA single-strand breaks (SSBs) and alkali-labile sites induced by exposure to the nitric oxide (NO) donors sodium nitroprusside (SNP) and 3-morpholinosydnomine hydrochloride (SIN-1) in the whole genome and in long interstitial telomeric repeat sequence (ITRS) blocks from Chinese hamster cells. The relative density of DNA damage generated in the ITRS by X-rays was similar to that induced in the genome overall, whereas it was 1.7 times higher when the alkylating agent MNNG was assayed. Nevertheless, after SNP or SIN-1 treatment, ITRSs proved to be 2.8 and 2.7 times relatively more damaged, respectively, than the whole genome. When the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) was not active, as in XR-C1 mutant cells, the repair kinetics in the whole genome did not differ from that in the parental cell line with X-ray or SNP exposure. However, whereas the SSBs and alkali-labile sites induced in the ITRS by X-rays exhibited rejoining kinetics similar to that of the parental cell line, the damage induced by SNP was more slowly rejoined. This implies a role for DNA-PKcs in the repair of DNA damage induced by NO, especially in ITRSs. The results demonstrated intragenomic heterogeneity of NO-induced DNA damage and repair; there was a higher density of DNA damage in the ITRS blocks, possibly because of their guanine richness. This suggests that a parallel process may occur in the terminal telomeres, which has implications for premature aging and neoplastic development by chronic NO exposure in vivo.

Testicular tissue nitric oxide and thiobarbituric acid reactive substance levels: evaluation with respect to the pathogenesis of varicocele

The aim of the present study is to evaluate tissue nitric oxide (NO) and thiobarbituric acid reactive substance (TBARS) levels in testicular tissue, and to determine their relationship with seminal parameters in order to explain possible effects on varicocele pathophysiology. Ten adult male Wistar rats at 8 weeks old underwent partial left renal vein ligation. A sham operation was performed on control rats in a second group of another ten rats. All animals were killed 4 weeks after surgery. The testes were removed and histological changes were observed by light microscopy with haematoxylin and eosin stain on half of each testis. The rest of testis was used for the evaluation of testicular tissue NO and TBARS levels. Epididymal aspirated seminal plasma was used for semen analysis and morphological analysis was carried out according to Kruger's criteria. Statistical analysis was performed by using Mann-Whitney U-tests and Spearman rank correlations between the two groups for NO and TBARS levels and for seminal parameters. Testicular tissue NO and TBARS levels (mean+/-SEM) were 62.8+/-10.1 micromol/g protein and 4.7+/-0.3 nmol/g protein in group 1. These parameters were 16.9+/-2.2 micromol/g protein and 3.1+/-0.2 nmol/g protein in the group 2 controls. There were significant differences between these parameters ( P(NO)=0.000, P(TBARS)=0.001). Although a positive and significant correlation between testicular tissue NO and TBARS levels was found ( r(s)=0.739, P=0.014), there was only a strong negative correlation between NO levels and sperm motility in group 1 ( r(s)=-0.815, P=0.004). We found that this effect of NO on sperm motility was independent from TBARS levels after regression analysis ( r(2)=-0.687, beta=0.825, P=0.034). Although there were statistically significant differences in seminal parameters between the two groups, there was no difference between them in the histopathological examination. We found that sperm motility was significantly related to testicular tissue NO levels only. Thus, we suggest that NO is an important mediator in the pathogenesis of varicocele. TBARS and other substances have been effective via NO pathways.

Evaluation of nuclear DNA damage in spermatozoa from infertile men with varicocele

OBJECTIVE

To examine levels of sperm DNA damage and oxidative stress (OS) in infertile men with varicocele.

DESIGN

Prospective controlled study.

SETTING

Male infertility clinic, Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio.

PATIENT(S)

Thirty-one infertility patients and 16 fertile controls.

INTERVENTION(S)

Sperm DNA fragmentation index (DFI), levels of seminal reactive oxygen species (ROS), and total antioxidant capacity (TAC) were assessed using the sperm chromatin structure assay, chemiluminescence assay, and enhanced chemiluminescence assay, respectively. ROS-TAC score was calculated as a measure of OS.

MAIN OUTCOME MEASURE(S)

Median (interquartile range) DFI and ROS-TAC scores.

RESULT(S)

Sixteen of the 31 patients had left varicocele [grade I (n = 3), grade II (n = 10), and grade III(n = 3)], and the remaining 15 had normal genital examination. Patients with varicoceles had significantly higher percent DFI than controls (25%, range: 20%-35%; vs. 15%, range: 10%-22%). Patients with varicoceles had significantly lower ROS-TAC scores (21, range: 9.5-31) than the infertile patients with normal genital examination (34, range: 28-42) or the controls (40.3, range: 38-44).

CONCLUSION(S)

Infertile men with varicoceles showed significantly increased spermatozoal DNA damage that appears to be related to high levels of OS in semen.

Preliminary report on nitric oxide-mediated oxidative damage in adolescent varicocele

BACKGROUND

The current study was designed to characterize the process of nitric oxide (NO) and peroxynitrite generation through the determination of nitrotyrosine concentration in the dilated veins of varicoceles in adolescents.

METHODS

Ten adolescents with a median age of 13 years (range 12-17) affected by a left idiopathic varicocele (grade II and III) were studied. Whole blood samples were withdrawn from a peripheral vein at time of induction of anaesthesia, and from a dilated spermatic vein before ligation. Peripheral blood samples from five adolescents undergoing minor surgical procedures were used as controls. The nitrotyrosine concentration was evaluated by a sandwich enzyme-linked immunosorbent assay (ELISA), using a monoclonal anti-nitrotyrosine antibody and Western blot analysis.

RESULTS

Plasma nitrotyrosine concentrations were significantly greater in the spermatic vein when compared with the peripheral vein (P = 0.031). Nitrotyrosine in plasma of controls did not show any significant difference in comparison with peripheral samples from varicocele patients. Western blot analysis confirmed the above data.

CONCLUSIONS

In adolescents with a varicocele, there is an increase in nitrotyrosine concentration within the spermatic vein that can cause protein nitration and cytotoxicity via its reaction with various molecular targets. This could have repercussions on both sperm and testis function. We conclude that an oxidative stress status is present and should be considered as an indication for varicocele treatment in the adolescent.

Incidence of varicoceles in patients with ankylosing spondylitis evaluated by physical examination and color duplex sonography

OBJECTIVES

To assess the incidence of varicocele in ankylosing spondylitis (AS) in comparison to healthy age-matched controls.

METHODS

Twenty-one male patients with AS who were not taking disease-modifying antirheumatic drugs (eg, sulfasalazine, a well-known cause of drug-induced infertility) and age-matched healthy controls were evaluated with both physical examination and color duplex sonography for varicocele. The maximal vein diameters of pampiniform plexus and duration of reflux were recorded. Semen samples were also analyzed in both groups.

RESULTS

Patients with AS had a higher incidence of clinical varicoceles (52%) compared with the healthy age-matched controls (20%). On color Doppler examination, 12 patients (57%) had varicocele (3 bilateral and 9 on the left side) and 6 controls had varicocele on the left side. The patients with AS had significantly greater vein diameters of pampiniform plexus on the left and right side compared with the controls.

CONCLUSIONS

The incidence of varicocele is increased in patients with AS, and its clinical relevance needs to be evaluated.

Seminal plasma nitric oxide concentration in oligo- and/or asthenozoospermic subjects with/without varicocele

There is an inverse correlation between seminal plasma nitric oxide (NO) concentration and sperm parameters (motility and concentration) in patients with varicocele. This study investigated whether this occurs in patients with oligo- and/or asthenozoospermia due to causes other than varicocele. A total of 69 (19 with varicocele and oligo- and/or asthenozoospermia [group 1], 30 from oligo- and/or asthenozoospermic ones without varicocele [group 2], and 20 from healthy subjects [control group]) semen samples were analyzed. While group 1 had a significantly higher NO concentration in the seminal plasma compared to both the control group and group 2, there was no significant difference between group 2 and the control group (p >.05). In group 1, but not in the other groups, there was an inverse correlation between the seminal plasma NO concentration and sperm motility and concentration. NO production could be specifically related to the varicocele, since NO production in oligo- and/or asthenozoospermia cases without varicocele is not increased.