Effects of psychological stress on male reproduction: a review

Stress and Pregnancy Outcomes: A Review of the Literature

The human body has the ability to adapt to changing circumstances, and mobilizes various biological systems in order to do so. When exposed to stressful conditions, the endocrine, nervous, and immune systems come together to aid in maintaining homeostasis; however, during periods of chronic stress, these systems can become maladaptive and lead to long-term detrimental health outcomes. Amongst the lingering effects associated with chronic stress exposure, increasingly, studies are identifying a link to adverse pregnancy and neonatal outcomes. This review explores what has been uncovered in the field to date, and examines the effects of stress on fertility and gestation. Establishing additional factors which put women at risk for adverse pregnancy outcomes can aid in identifying a vulnerable population who could benefit from early stress-reducing interventions.

Impact of stress on male fertility: role of gonadotropin inhibitory hormone

Studies have implicated oxidative stress-sensitive signaling in the pathogenesis of stress-induced male infertility. However, apart from oxidative stress, gonadotropin inhibitory hormone (GnIH) plays a major role. The present study provides a detailed review of the role of GnIH in stress-induced male infertility. Available evidence-based data revealed that GnIH enhances the release of corticosteroids by activating the hypothalamic-pituitary-adrenal axis. GnIH also mediates the inhibition of the conversion of thyroxine (T4) to triiodothyronine (T3) by suppressing the hypothalamic-pituitary-thyroidal axis. In addition, GnIH inhibits gonadotropin-releasing hormone (GnRH), thus suppressing the hypothalamic-pituitary-testicular axis, and by extension testosterone biosynthesis. More so, GnIH inhibits kisspeptin release. These events distort testicular histoarchitecture, impair testicular and adrenal steroidogenesis, lower spermatogenesis, and deteriorate sperm quality and function. In conclusion, GnIH, via multiple mechanisms, plays a key role in stress-induced male infertility. Suppression of GnIH under stressful conditions may thus be a beneficial prophylactic and/or therapeutic strategy.

Lifestyle, Insulin Resistance and Semen Quality as Co-Dependent Factors of Male Infertility

Infertility is a problem that affects millions of couples around the world. It is known as a disease of couples, not individuals, which makes diagnosis difficult and treatment unclear. Male infertility can have many causes, from mechanical ones to abnormal spermatogenesis or spermiogenesis. Semen quality is determined by a number of factors, including those dependent on men themselves, with the number of infertile men growing every year. These include, e.g., diet, physical activity, sleep quality, stress, among many others. As these factors co-exist with insulin resistance, which is a disease closely related to lifestyle, it has been singled out in the study due to its role in affecting semen quality. In order to examine connections between lifestyle, insulin resistance, and semen quality, a review of literature published from 1989 to 2020 in the following databases PubMed/Medline, EMBASE (Elsevier), Scopus, Web of Science, and Google Scholar was performed. Hence, semen quality, environment, and insulin resistance are interrelated, thus it is difficult to indicate which aspect is the cause and which is the effect in a particular relationship and the nature of possible correlations. Since the influence of lifestyle on semen quality has been extensively studied, it is recommended that more thorough research be done on the relationship between insulin resistance and semen quality, comparing the semen quality of men with and without insulin resistance.

Reproductive development of male rats exposed in utero to stress and/or sertraline

Despite increased prescription of sertraline during pregnancy, little is known about its action on reproductive development. Therefore, the present study aimed to investigate the impact that stress, associated or not with sertraline, causes on the reproductive development of male rats. Pregnant Wistar rats were divided into 4 groups (n = 16/group): CO - received filtered water; SE - received 20 mg/kg sertraline; ST - submitted to restraint stress and received filtered water; SS - submitted to restraint stress and received sertraline. The treatment was carried out from gestational days (GD) 13 to 20. The animals were euthanized on GD 20 (n = 8/group), postnatal day (PND) 45 (n = 8/group) and PND 110 (n = 8/group). The testes and epididymis were analyzed histologically, and immunohistochemistry was performed on the testes by proliferating cell nuclear antigen (PCNA) and the Wilms tumor protein (Wt1). Sperm quality was also analyzed on PND 110. The evolution of body weight, anogenital distance (AGD), and puberty installation day were also verified. Statistical analysis: Two-way ANOVA or Kruskal-Wallis test (p ≤ 0.05). Fetal testes presented a large number of acidophilic cells in the sertraline-exposed groups. The SS group also showed a decrease in the nuclear volume of Leydig cells. This same group showed low expression of PCNA and Wt1, decreased weight of the testes and epididymis, lower AGD, and delayed puberty installation. The adulthood groups exposed to sertraline presented alterations in sperm morphology and motility. The results demonstrated that prenatal exposure to sertraline compromises the development of the rat reproductive system.

Effect of Phosphodiesterase-5 Inhibitors on the Treatment of Male Infertility: A Systematic Review and Meta-Analysis

Purpose

Male infertility is a worldwide problem with limitations in the treatment. Phosphodiesterase-5 inhibitors (PDE5is) is the first choice for the treatment of erectile dysfunction, more and more studies show that it has a certain effect on male infertility in recent years. But there was currently no high quality of systematic review to evaluate the effects of PDE5is on semen quality.

Materials and Methods

We retrieved the electronic databases of MEDLINE, PubMed, Web of Science, EMBASE, etc. Related randomized controlled trials (RCTs) were collected and selected up to May 20, 2020. We have searched literature with terms “male infertility”, “phosphodiesterase-5 inhibitors”, “PDE5i”, “Tadalafil”, “Sildenafil”, “Vardenafil”, “Udenafil”, “Avanafil”, “semen”, and “sperm”. Mean value and its standard deviation were used to perform quantitative analysis. All statistical analyses were conducted by RevMan 5.3 and Stata software.

Results

There were a total of 1,121 participants in the nine included studies. There was a statistically significant improvement treated with PDE5is compared with sham therapy, which including sperm concentration (mean difference [MD]=1.96, 95% confidence interval [CI]=1.70–2.21, p<0.001; MD=3.22, 95% CI=1.96–4.48, p<0.001), straight progressive motility (%) Grade A (MD=3.71, 95% CI=2.21–5.20, p<0.001), sperm motility (MD=8.09, 95% CI=7.83–8.36, p<0.001), morphologically normal spermatozoa (%) (MD=0.67, 95% CI=0.20–1.15, p=0.005; MD=1.27, 95% CI=0.02–2.52, p=0.05), sperm abnormalities (%) (MD=−0.64, 95% CI=−0.81–−0.47, p<0.001), and progressive motile sperm (MD=5.34, 95% CI=3.87–6.81, p<0.001).

Conclusions

In this meta-analysis of nine RCTs, treatment with PDE5is could improve some indicators of male sperm.

Changes in nitric oxide, carbon monoxide, hydrogen sulfide and male reproductive hormones in response to chronic restraint stress in rats

Gasotrasmitters are endogenously synthesized gaseous molecules that are engaged in cellular physiological and pathological processes. Stress influences various physiological aspects of an organism and amends a normal system's functions, including those of the reproductive system. This study aims to investigate the effect of long-term exposure to restraint stress on the male reproductive system as well as the possible impact of stress on the levels of nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H₂S), and the expression of their producing-enzymes. In this study, rats were subjected to the restraint condition for 2 h per day and 7 days per week for 8 consecutive weeks. The results revealed decreases in the serum levels of kisspeptin-1(Kiss-1), gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and dehydroepiandrosterone sulfate (DHEA-s); however, corticosterone, gonadotropin-inhibitory hormone (GnIH), estradiol (E2) and prolactin levels increased following restraint stress. The mRNA expression levels of NO synthases (NOSs); neuronal NOS (nNOS), inducible NOS (iNOS) and H₂S synthases; cystathionine-γ-lyase- (CSE), 3-mercaptopyruvate-sulfurtransferase- (3MST) and CO-producing enzyme; heme oxygenase-2 (HO-2) were upregulated in the hypothalamus of restraint rats. Testicular mRNA expression levels of endothelial NOS (eNOS), nNOS, HO-1 and HO-2 were upregulated whereas cystathionine β-synthase (CBS), CSE and 3MST expression levels were downregulated following restraint stress. Concentrations of NO increased in the testes but decreased in the semen of restraint rats. On the contrary, CO levels were reduced in the testes while they were elevated in the semen, whereas H₂S concentrations decreased in both testes and semen of restraint rats. Concentrations of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), as well as total antioxidant capacity (TAC) rose in the testes, while they declined in the semen of the restraint group. Restraint stress decreases the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in the testes while increasing them in the semen. Collectively, restraint stress negatively impacts male reproductive functions and modulates gasotransmitters producing-enzymes expression in the hypothalamus and testes.

The effects of maternal separation stress experienced by parents on male reproductive potential in the next generation

There is little information available about the effects of early-life parental stress on the reproductive potential of the next generation. The aim of this study is to examine the reproductive potential of male mice whose parents experienced maternal separation stress. In the present study, male first-generation offspring from parents were undergone of maternal separation (MS) were examined. Sperm characteristics, histological changes in testis, reactive oxygen species (ROS) production, expression of apoptotic and inflammatory genes and proteins were assessed. Findings showed that MS experienced by parents significantly decreased the morphology and viability of spermatozoa. Furthermore, significant changes in testicular tissue histology were observed. Increased production of ROS, decreased glutathione peroxidase (GPX) and adenosine triphosphate (ATP) concentrations, and affected the expression of genes and cytokines involved in inflammation. Finally, the mean percentage of caspase-1 and NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) positive cells was significantly higher in first-generation group. MS experienced by parents may negatively affect the reproduction of first generation offspring.

Effect of diazepam, sertraline and melatonin on the stress-induced reproductive disorders and intrauterine growth restriction in female rats

Objective: Psychological stress is an important factor triggering depression and anxiety. Infertility is known to cause stress; however, it is not clearly known whether stress causes infertility as well. In addition, there are different opinions accounting for the relation of stress-induced oxidative stress to infertility and intrauterine growth restriction. The aim of the study is to examine the effect of sertraline, diazepam and melatonin on the infertility, intrauterine growth restriction and oxidative stress that can be caused by forced immobilization stress management (FISM) in female rats.Materials and methods: Wistar rats were grouped as healthy rats (HG) applied distilled water, stress treated control group (SC), and 20 mg/kg sertraline + stress (SS), 2 mg/kg diazepam + stress (DS) and 10 mg/kg melatonin + stress (MS) treated rats. The medicines were administered orally once a day for 30 days. At the end of this period, oxidant/antioxidant parameters were measured through the blood samples collected from the tail veins of all rats. Then the rats were kept in a suitable environment for 2 months for breeding.Results: FISM caused oxidative stress in blood serum of animals, infertility and intrauterine growth restriction (decrease in birth weight of the baby). Best medicines to suppress FISM-related oxidative stress are melatonin > diazepam > sertraline respectively, while sertraline > diazepam > melatonin were most successful in terms of preventing infertility. The best medicines preventing the FISM-caused intrauterine growth restriction were found to be melatonin > diazepam > sertraline, respectively.Conclusion: FISM causes oxidative stress in animals. Oxidative stress is understood to affect the intrauterine growth negatively although it is not a major component in the pathogenesis of infertility. While melatonin is only effective in preventing the oxidative stress-related intrauterine growth restriction, antidepressants and anxiolytic treatment were found to be helpful in preventing both infertility and intrauterine growth restriction.

Oxidative stress, inflammatory reactions and apoptosis mediated the negative effect of chronic stress induced by maternal separation on the reproductive system in male mice

Exposure to severe and long-lasting stressors during early postnatal life negatively affects development of the brain and associated biological networks. Maternal separation (MS) is a valid stressful experience in early life that adversely affects neurobiological circuits. In the present study, we aimed to evaluate the effects of MS on sperm quality and histology of the testis in adult male mice. In this study, male mice were subjected to MS during post-natal days (PND) 2-14. Sperm parameters, histological alterations in the testicular tissue, ROS production (using DCFH-DA assay), gene expression of TLR4, NLRP3, TNFα, BAX, ASC, caspase-1 and BCL-2 (using RT-PCR), protein levels of caspase-3 and caspase-8 (using western blotting), and protein levels of IL-1β, IL-18, GPx and ATP (using ELISA) as well as protein expression of caspase-1 and NLRP3 (using immunocytochemistry) were evaluated. Findings showed that MS decreased count, morphology and viability of spermatozoa. MS decreased the diameter of seminiferous tubules and decreased the thickness of seminiferous epithelium. Furthermore, MS increased the level of ROS production and decreased the concentrations of GPx and ATP. MS led to increased expression of TLR4, NlRP3, TNFα, caspase-1, ASC, IL-1β and IL-18. In addition, MS induced apoptosis as evidenced by increased BAX, caspase-3 and caspase-8 as well as decreased BCL-2 expression. We concluded that early life stress induced by MS has detrimental effects on sperm parameters and testicular tissue. Our results suggest that these effects are mediated by activation of ROS production, and alterations in mitochondrial function, inflammatory processes and apoptosis pathways.

Social support modifies an association between work stress and semen quality: Results from 384 Chinese male workers

OBJECTIVE

Psychosocial factors have been associated with a decline of the quality of semen. The study was aimed at (i) estimating the association between work stress and semen quality and (ii) exploring the moderating effect of social support in semen parameters among Chinese male workers.

METHODS

Data were obtained from 384 adult male workers recruited from April 2014 to December 2015 in Chongqing, China. Participants completed a questionnaire assessing demographic and life-style factors. Work stress and social support was measured by the Chinese version of a 22-item Job Content Questionnaire (JCQ). They underwent a physical examination and provided a semen sample.

RESULTS

Subjects with high work stress were associated with a higher risk of being classified below WHO's thresholds for "normal," defined by sperm concentration (OR 2.14, 95% CI 1.24-3.68, p = .006) or total sperm count (OR 1.95, 95% CI 1.13-3.36, p = .02) criteria than subjects with low work stress were. However, these adverse associations were not observed among subjects with high social support (p = .80 for sperm concentration, and p = .39 for total sperm count). Interaction effects between social support and work stress on sperm concentration (p = .002) and total sperm count (p = .02) were detected.

CONCLUSION

Work stress is associated with lower levels of semen quality. Social support attenuates the negative association between work stress and semen quality, which may have implications for reproductive health.

The effect of chronic and acute stressors, and their interaction, on testes function: an experimental test during testicular recrudescence

Organisms are expected to invest less in reproduction in response to a stressor, but theory predicts that this effect should depend on the frequency and duration of stressors in the environment. Here, we investigated how an acute stressor affected testes function in a songbird, and how chronic stressors influenced the acute stress response. We exposed male dark-eyed juncos (Junco hyemalis) either to chronic or minimal (control) disturbance during testicular recrudescence, after which we measured baseline testosterone, testosterone after an acute handling stressor, and capacity to produce testosterone after hormonal stimulation. In a 2×2 design, we then killed males from the two chronic treatment groups either immediately or after an acute stressor to investigate the effect of long- and short-term stressors on the testicular transcriptome. We found that chronically disturbed birds had marginally lower baseline testosterone. The acute stressor suppressed testosterone in control birds, but not in the chronic disturbance group. The ability to elevate testosterone did not differ between the chronic treatments. Surprisingly, chronic disturbance had a weak effect on the testicular transcriptome, and did not affect the transcriptomic response to the acute stressor. The acute stressor, on the other hand, upregulated the cellular stress response and affected expression of genes associated with hormonal stress response. Overall, we show that testicular function is sensitive to acute stressors but surprisingly robust to long-term stressors, and that chronic disturbance attenuates the decrease in testosterone in response to an acute stressor.

The sperm factor: paternal impact beyond genes

The fact that sperm carry more than the paternal DNA has only been discovered just over a decade ago. With this discovery, the idea that the paternal condition may have direct implications for the fitness of the offspring had to be revisited. While this idea is still highly debated, empirical evidence for paternal effects is accumulating. Male condition not only affects male fertility but also offspring early development and performance later in life. Several factors have been identified as possible carriers of non-genetic information, but we still know little about their origin and function and even less about their causation. I consider four possible non-mutually exclusive adaptive and non-adaptive explanations for the existence of paternal effects in an evolutionary context. In addition, I provide a brief overview of the main non-genetic components found in sperm including DNA methylation, chromatin modifications, RNAs and proteins. I discuss their putative functions and present currently available examples for their role in transferring non-genetic information from the father to the offspring. Finally, I identify some of the most important open questions and present possible future research avenues.

Lifestyle causes of male infertility

Objective

To examine the potential effects of lifestyle factors on male reproductive health. Evidence of a global decline in human sperm quality over recent decades has been accumulating. Environmental, occupational, and modifiable lifestyle factors may contribute to this decline. This review focuses on key lifestyle factors that are associated with male infertility such as smoking cigarettes, alcohol intake, use of illicit drugs, obesity, psychological stress, advanced paternal age, dietary practices, and coffee consumption. Other factors such as testicular heat stress, intense cycling training, lack of sleep and exposure to electromagnetic radiation from mobile phone use are briefly discussed.

Materials and method

A comprehensive literature search was performed to identify and synthesise all relevant information, mainly from within the last decade, on the major lifestyle factors associated with male infertility and semen quality. Database searches were limited to reports published in English only. A manual search of bibliographies of the reports retrieved was conducted to identify additional relevant articles.

Results

In all, 1012 articles were identified from the database search and after reviewing the titles and abstract of the reports, 104 articles met the inclusion criteria. Of these, 30 reports were excluded as the full-text could not be retrieved and the abstract did not have relevant data. The remaining 74 reports were reviewed for data on association between a particular lifestyle factor and male infertility and were included in the present review.

Conclusion

The major lifestyle factors discussed in the present review are amongst the multiple potential risk factors that could impair male fertility. However, their negative impact may well be mostly overcome by behaviour modification and better lifestyle choices. Greater awareness and recognition of the possible impact of these lifestyle factors are important amongst couples seeking conception.

Between-litter variation in developmental studies of hormones and behavior: Inflated false positives and diminished power

Developmental studies of hormones and behavior often include littermates-rodent siblings that share early-life experiences and genes. Due to between-litter variation (i.e., litter effects), the statistical assumption of independent observations is untenable. In two literatures-natural variation in maternal care and prenatal stress-entire litters are categorized based on maternal behavior or experimental condition. Here, we (1) review both literatures; (2) simulate false positive rates for commonly used statistical methods in each literature; and (3) characterize small sample performance of multilevel models (MLM) and generalized estimating equations (GEE). We found that the assumption of independence was routinely violated (>85%), false positives (α=0.05) exceeded nominal levels (up to 0.70), and power (1-β) rarely surpassed 0.80 (even for optimistic sample and effect sizes). Additionally, we show that MLMs and GEEs have adequate performance for common research designs. We discuss implications for the extant literature, the field of behavioral neuroendocrinology, and provide recommendations.

Melatonin ameliorates restraint stress-induced oxidative stress and apoptosis in testicular cells via NF-κB/iNOS and Nrf2/ HO-1 signaling pathway

Decline in semen quality has become a global public health concern. Psychological stress is common in the current modern society and is associated with semen decline. Increasing evidence demonstrated that melatonin has anti-apoptotic and antioxidant functions. Whether melatonin can ameliorate the damage in testes induced by psychological stress has never been investigated. Here, a mouse model of restraint stress demonstrated that melatonin normalized the sperm density decline, testicular cells apoptosis, and testicular oxidative stress in stressed male mice. Melatonin decreased reactive oxygen species (ROS) level, increased superoxide dismutase (SOD) and glutathione (GSH) activities, and downregulated inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) activities in stressed mice testes. Furthermore, melatonin reduced the stress-induced activation of the NF-κB signaling pathway by decreasing the phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) and p65 nuclear translocation. In addition, melatonin upregulated the expression of anti-oxidant proteins including nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Meanwhile, in vitro studies also demonstrated melatonin could reduce oxidative apoptosis of testicular cells. Collectively, melatonin mitigated psychological stress-induced spermatogenic damage, which provides evidence for melatonin as a therapy against sperm impairment associated with psychological stress.

Indian folklore medicine in managing men's health and wellness

India is a home for a large variety of plants with remarkable medicinal and pharmacological value. Traditional medicine in the form of Ayurveda, Siddha and Unani has used many of these plants since ancient days for treating and curing various ailments of the body. When it comes to issues related to reproductive health, people still hesitate to discuss and/or accept it openly and hence look for alternate and natural remedies. The various tribal populations distributed across different parts of the country still use these plant extracts in various formulations for maintenance of good health. The medical utilities of several of these plants have been documented; however, there are many more, whose potential is yet to be explored. This review discusses the role of various plants grown in the Indian subcontinent that have been widely used in maintaining various aspects of reproductive health in men such as infertility, aphrodisiac, contraception, libido, sexually transmitted infections and reproductive tract cancers as well as in treating chronic disorders.

Animal models of erectile dysfunction

Erectile dysfunction (ED) is a prevalent male sexual dysfunction with profound adverse effects on the physical and the psychosocial health of men and, subsequently, on their partners. The expanded use of various types of rodent models has produced some advances in the study of ED, and neurophysiological studies using various animal models have provided important insights into human sexual dysfunction. At present, animal models play a key role in exploring and screening novel drugs designed to treat ED.

Role of hippocampus mitogen-activated protein kinase phosphatase-1 mRNA expression and DNA methylation in the depression of the rats with chronic unpredicted stress

Stressful life events especially the chronic unpredictable stress are the obvious precipitating factors of depression. The biological information transduction in cells plays an important role in the molecular biology mechanism of depression. Mitogen-activated protein kinase phosphatase-1 (MKP-1) regulates the cell physiological activity and involves in the adjustment of neural plasticity, function, and survival. This experiment tried to explore the possible effects of MKP-1 in hippocampus on depression of rats by determining the expression of MKP-1 mRNA and DNA methylation in MKP-1 gene promoter. The animal model was established by chronic unpredictable stress, and evaluated by open-field test and weight changes. All the rats were divided into the sham stimulation, the physiological saline, and the fluoxetine (1.25, 2.50, and 5.00 mg/kg) groups randomly. The expression of MKP-1 mRNA in the hippocampus was measured by RT-PCR and the methylation of MKP-1 promoter DNA was detected by COBRA. The chronic unpredicted stress (1) increased the animal movement scores in open-field test, and fluoxetine could prevent this increasement; (2) increased the body weight, and fluoxetine could not prevent this increasement; and (3) increased MKP-1 mRNA expression in the hippocampus, and fluoxetine could prevent it. However, fluoxetine did not influence the DNA methylation of MKP-1 gene promoter in the hippocampus during the chronic unpredicted stress. MKP-1 in the hippocampus might be involved in the etiology of depression, and DNA methylation of MKP-1 gene promoter in the hippocampus did not related with the depression.

Oxidative status in testis and epididymal sperm parameters after acute and chronic stress by cold-water immersion in the adult rat

Stress is associated with detrimental effects on male reproductive function. It is known that stress increases reactive oxygen species (ROS) generation in the male reproductive tract. High ROS levels may be linked to low sperm quality and male infertility. However, it is still not clear if ROS are generated by stress in the testis. The objective of this study was to characterize the role of oxidative stress induced by cold-water immersion stress in the testis of adult male rats and its relation with alterations in cauda epididymal sperm. Adult male rats were exposed to acute stress or chronic stress by cold-water immersion. Rats were sacrificed at 0, 6, 12, and 24 hours immediately following acute stress exposure, and after 20, 40, and 50 days of chronic stress. ROS production increased only at 6 hours post-stress, while the activity and expression of antioxidant enzymes, lipid peroxidation (LPO), and sperm parameters were not modified in the testis. Corticosterone increased immediately after acute stress, whereas testosterone was not modified. After chronic stress, testicular absolute weight decreased; in addition, ROS production and LPO increased at 20, 40, and 50 days. The activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) decreased throughout the duration of chronic stress and the activity of catalase (CAT) decreased at 40 and 50 days, and increased at 20 days. The expression of copper/zinc superoxide dismutase (SOD1) and CAT were not modified, but the expression of phospholipid hydroperoxide glutathione peroxidase (GPx-4) decreased at 20 days. Motility, viability, and sperm count decreased, while abnormal sperm increased with chronic stress. These results suggest that during acute stress there is a redox state regulation in the testis since no deleterious effect was observed. In contrast, equilibrium redox is lost during chronic stress, with low enzyme activity but without modifying their expression. In addition, corticosterone increased while testosterone decreased, this decrease is related to the negative effects seen in sperm.

Effects of work and life stress on semen quality

OBJECTIVE

To evaluate associations between work-related stress, stressful life events, and perceived stress and semen quality.

DESIGN

Cross-sectional analysis.

SETTING

Northern California.

PATIENT(S)

193 men from the Child Health and Development Studies evaluated between 2005-2008.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Measures of stress including job strain, perceived stress, and stressful life events; outcome measures of sperm concentration, percentage of motile sperm, and percentage of morphologically normal sperm.

RESULT(S)

We found an inverse association between perceived stress score and sperm concentration (estimated coefficient b=-0.09×10(3)/mL; 95% confidence interval [CI]=-0.18, -0.01), motility (b=-0.39; 95% CI=-0.79, 0.01), and morphology (b=-0.14; 95% CI, -0.25, -0.04) in covariate-adjusted linear regression analyses. Men who experienced two or more stressful life events in the past year compared with no stressful events had a lower percentage of motile sperm (b=-8.22; 95% CI, -14.31, -2.13) and a lower percentage of morphologically normal sperm (b=-1.66; 95% CI, -3.35, 0.03) but a similar sperm concentration. Job strain was not associated with semen parameters.

CONCLUSION(S)

In this first study to examine all three domains of stress, perceived stress and stressful life events but not work-related stress were associated with semen quality.

Occupational, life stress and family functioning: does it affect semen quality?

BACKGROUND AND AIMS

Although psychological stress has been implicated as a cause of idiopathic infertility in both men and women, it has received little scientific attention among males as compared to females. The aim of the study was to examine the association between occupational, life stress, family functioning and semen quality.

METHODS AND RESULTS

The study population consisted of 327 men who were attending an infertility clinic for diagnostic purposes. Psychological stress was assessed based on two questionnaires: The Subjective Work Characteristics Questionnaire and the Perceived Stress Scale. The level of satisfaction with family functioning and support was evaluated by means of the APGAR Family Scale. The findings suggest that, on the one hand, exposure to occupational stressors can be negatively associated with semen quality (there was a positive association between stress and the percentage of sperm with DNA damage (p = 0.03) and atypical sperm (p = 0.05)); on the other hand, there was no correlation between the level of life stress and semen quality indicators. Negative associations were found between satisfaction with family functioning and the percentage of motile sperm cells (p = 0.02), VAP (p = 0.05), VSL (p = 0.05) and VCL (p = 0.04).

CONCLUSION

The study indicates that occupational stress can affect male semen quality; however, due to limited data on this issue, the obtained results should be confirmed in longitudinal studies.

Chronic psychosocial stress makes rats more 'pessimistic' in the ambiguous-cue interpretation paradigm

Human decisions are often biased by emotions. Stressed and depressed individuals tend to make negative, pessimistic judgements while those in positive affective states are often more optimistic. Chronic psychosocial stress has previously been shown to induce a spectrum of behavioural and physiological changes in rats that are considered the correlates of depressive symptoms in humans. In this study, we investigate whether chronic social defeat makes animals more 'pessimistic'. To measure the changes in cognitive judgement bias, we applied the ambiguous-cue interpretation paradigm. In the operant boxes, the rats were trained to press one lever in response to one tone to receive a reward and to press another lever in response to a different tone to avoid punishment. Cognitive bias was tested by measuring the pattern of animals' responses to a tone of intermediate frequency (ambiguous-cue). To induce chronic psychosocial stress, we subjected the animals to daily social defeat in the resident-intruder paradigm for 3 weeks. We report that chronic psychosocial stress makes rats more pessimistic.

Association of state and trait anxiety to semen quality of in vitro fertilization patients: a controlled study

OBJECTIVE

To investigate the relationship between semen quality and state/trait anxiety in patients enrolled in an in vitro fertilization (IVF) program and in control subjects.

DESIGN

Cross-sectional study.

SETTING

Centre for Reproductive Medicine and Biology, European Hospital, Rome.

PATIENT(S)

Ninety-four first-attempt IVF patients and 85 age-matched, random subjects recruited in the period July 2006 through March 2008.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Behavioral features of stress, including state and trait anxiety, self-perceived impact of physical disturbance on everyday activities, ethanol consumption, cigarette smoking, and semen parameters such as semen volume, sperm concentration, total count, motility, morphology, and DNA fragmentation.

RESULT(S)

Increased levels of both state and trait anxiety were associated with lower semen volume, sperm concentration and count, reduced sperm motility, and increased sperm DNA fragmentation of IVF patients, thus influencing seminal parameters at the macroscopic and cellular/subcellular levels. Similar results were obtained in the controls.

CONCLUSION(S)

Our data confirm previous observations with state anxiety and show that trait anxiety also is negatively associated with male fertility.

Effect of reproductive status on hypothalamic-pituitary-adrenal (HPA) activity and reactivity in male California mice (Peromyscus californicus)

Previous studies indicate that reproductive condition can alter stress response and glucocorticoid release. Although the functional significance of hypothalamic-pituitary-adrenal (HPA) axis modulation by breeding condition is not fully understood, one possible explanation is the behavior hypothesis, which states that an animal's need to express parental behavior may be driving modulation of the HPA axis. This possibility is consistent with findings of blunted activity and reactivity of the HPA axis in lactating female mammals; however, effects of reproductive status on HPA function have not been well characterized in male mammals that express parental behavior. Therefore, we tested this hypothesis in the monogamous and biparental California mouse. Several aspects of HPA activity were compared in males from three reproductive conditions: virgin males (housed with another male), non-breeding males (housed with a tubally ligated female), and first-time fathers (housed with a female and their first litter of pups). In light of the behavior hypothesis we predicted that new fathers would differ from virgin and non-breeding males in several aspects of HPA function and corticosterone (CORT) output: decreased amplitude of the diurnal rhythm in CORT, a blunted CORT increase following predator-odor stress, increased sensitivity to glucocorticoid negative feedback, and/or a blunted CORT response to pharmacological stimulation. In addition, we predicted that first-time fathers would be more resistant to CORT-induced suppression of testosterone secretion, as testosterone is important for paternal behavior in this species. We found that virgin males, non-breeding males and first-time fathers did not display any CORT differences in diurnal rhythm, response to a predator-odor stressor, or response to pharmacological suppression or stimulation. Additionally, there were no differences in circulating testosterone concentrations. Adrenal mass was, however, significantly lower in new fathers than in virgin or non-breeding males. These results suggest that the behavior hypothesis does not explain HPA function across reproductive conditions in male California mice.

Recent trend in risk assessment of formaldehyde exposures from indoor air

Studies about formaldehyde (FA) published since the guideline of 0.1 mg/m(3) by the World Health Organization (WHO) in 2010 have been evaluated; critical effects were eye and nasal (portal-of-entry) irritation. Also, it was considered to prevent long-term effects, including all types of cancer. The majority of the recent toxicokinetic studies showed no exposure-dependent FA-DNA adducts outside the portal-of-entry area and FA-DNA adducts at distant sites were due to endogenously generated FA. The no-observed-adverse-effect level for sensory irritation was 0.5 ppm and recently reconfirmed in hypo- and hypersensitive individuals. Investigation of the relationship between FA exposure and asthma or other airway effects in children showed no convincing association. In rats, repeated exposures showed no point mutation in the p53 and K-Ras genes at ≤15 ppm neither increased cell proliferation, histopathological changes and changes in gene expression at 0.7 ppm. Repeated controlled exposures (0.5 ppm with peaks at 1 ppm) did not increase micronucleus formation in human buccal cells or nasal tissue (0.7 ppm) or in vivo genotoxicity in peripheral blood lymphocytes (0.7 ppm), but higher occupational exposures were associated with genotoxicity in buccal cells and cultivated peripheral blood lymphocytes. It is still valid that exposures not inducing nasal squamous cell carcinoma in rats will not induce nasopharyngeal cancer or lymphohematopoietic malignancies in humans. Reproductive and developmental toxicity are not considered relevant in the absence of sensory irritation. In conclusion, the WHO guideline has been strengthened.

Effect of vardenafil on semen parameters in infertile men: a pilot study evaluating short-term treatment

BACKGROUND

Severeal in vivo and in vitro studies have been carried out in order to evaluate the efficacy of long-term treatment with phosphodiesterase type-5 (PDE5) inhibitors (PDE5i) on spermatogenesis, but the results are still controversial.

AIM

To evaluate the effects of vardenafil on seminal parameters of infertile men after a short-term treatment.

MATERIALS/SUBJECTS AND METHODS

A total of 205 male subjects were randomized to receive a single dose of vardenafil 10 mg (73 men, group B), a single dose of vardenafil 10 mg every other day for 15 days (67 men, group C), and no treatment (65 men, group A). Semen parameters were evaluated before and after the end of the treatment in each of group A, B, and C, respectively. Additionally, an IIEF- 5 questionnaire was administered to all patients with erectile dysfunction (ED) before and after each treatment period.

RESULTS

The semen parameters in groups B and C has shown a significant increase in percentage forward motility after vardenafil administration as compared with baseline (p<0.001). In group C, we observed an increase in the mean semen volume and an improvement in the mean total sperm concentration (p<0.001) as compared with baseline.

CONCLUSIONS

We showed the efficacy of vardenafil in the treatment of ED and, on a large series of infertile patients, the positive effect on sperm motility after a single-dose administration. It also showed that after 15 days of treatment on alternate days is also achieved an improvement in sperm concentration.

Choline dehydrogenase polymorphism rs12676 is a functional variation and is associated with changes in human sperm cell function

Approximately 15% of couples are affected by infertility and up to half of these cases arise from male factor infertility. Unidentified genetic aberrations such as chromosomal deletions, translocations and single nucleotide polymorphisms (SNPs) may be the underlying cause of many cases of idiopathic male infertility. Deletion of the choline dehydrogenase (Chdh) gene in mice results in decreased male fertility due to diminished sperm motility; sperm from Chdh^−/− males have decreased ATP concentrations likely stemming from abnormal sperm mitochondrial morphology and function in these cells. Several SNPs have been identified in the human CHDH gene that may result in altered CHDH enzymatic activity. rs12676 (G233T), a non-synonymous SNP located in the CHDH coding region, is associated with increased susceptibility to dietary choline deficiency and risk of breast cancer. We now report evidence that this SNP is also associated with altered sperm motility patterns and dysmorphic mitochondrial structure in sperm. Sperm produced by men who are GT or TT for rs12676 have 40% and 73% lower ATP concentrations, respectively, in their sperm. rs12676 is associated with decreased CHDH protein in sperm and hepatocytes. A second SNP located in the coding region of IL17BR, rs1025689, is linked to altered sperm motility characteristics and changes in choline metabolite concentrations in sperm.

Imprisonment-Associated Sperm Clumping and Male Infertility

OBJECTIVE: This observational, retrospective study investigated infertility among Iraqi men who had been long-term prisoners of war. METHODS: Routine seminal fluid analyses were undertaken in former prisoners with suspected infertility attending the Ramadi Infertility Clinic, Ramadi, Iraq; semen samples were also microscopically evaluated in these patients. RESULTS: In 16 out of 38 patients (42%), male infertility was found to be associated with the formation of unusually large clumps of sperm. These sperm clumps contained large numbers of sperm; clumping led to sperm immobilization and infertility. CONCLUSIONS: The causes of sperm clumping are unclear. It is possible that the sperm clumping observed in the present study might be a result of developmental defects, possibly related to stress or other undiscovered factors, although this requires further investigation.

Male fertility: psychiatric considerations

OBJECTIVE

To examine: 1) current knowledge on normal biologic variation of seminal parameters; 2) how stress and psychological factors affect sperm quality in fertile and infertile males; and 3) how mental illness and psychopharmacologic agents can affect male fertility.

DESIGN

English-language Medline, Embase, and Psycinfo were searched for relevant publications (from 1970 to January 2011) for systematic review.

SETTING

None.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Possible effects of stress, mood, and psychotropic medications on male factor fertility.

RESULT(S)

Male-factor infertility is influenced by myriad factors (obesity, tobacco, etc.). Stress alone may reduce testosterone levels and spermatogenesis. Infertility assessment and treatment can lead to distress and negatively affect sperm samples. Available research has failed to control for potentially confounding variables.

CONCLUSION(S)

Although some trends have been identified, larger-scale studies that adequately control all confounding variables are needed before conclusions can be made about the relationship between stress, psychotropic agents, and male infertility.

Reproductive and developmental toxicity of formaldehyde: a systematic review

Formaldehyde, the recently classified carcinogen and ubiquitous environmental contaminant, has long been suspected of causing adverse reproductive and developmental effects, but previous reviews were inconclusive, due in part, to limitations in the design of many of the human population studies. In the current review, we systematically evaluated evidence of an association between formaldehyde exposure and adverse reproductive and developmental effects, in human populations and in vivo animal studies, in the peer-reviewed literature. The mostly retrospective human studies provided evidence of an association of maternal exposure with adverse reproductive and developmental effects. Further assessment of this association by meta-analysis revealed an increased risk of spontaneous abortion (1.76, 95% CI 1.20-2.59, p=0.002) and of all adverse pregnancy outcomes combined (1.54, 95% CI 1.27-1.88, p<0.001), in formaldehyde-exposed women, although differential recall, selection bias, or confounding cannot be ruled out. Evaluation of the animal studies including all routes of exposure, doses and dosing regimens studied, suggested positive associations between formaldehyde exposure and reproductive toxicity, mostly in males. Potential mechanisms underlying formaldehyde-induced reproductive and developmental toxicities, including chromosome and DNA damage (genotoxicity), oxidative stress, altered level and/or function of enzymes, hormones and proteins, apoptosis, toxicogenomic and epigenomic effects (such as DNA methylation), were identified. To clarify these associations, well-designed molecular epidemiologic studies, that include quantitative exposure assessment and diminish confounding factors, should examine both reproductive and developmental outcomes associated with exposure in males and females. Together with mechanistic and animal studies, this will allow us to better understand the systemic effect of formaldehyde exposure.

Workplace exposures and male infertility - a case-control study

OBJECTIVES

This study examined the association between male infertility and certain occupational exposures.

MATERIAL AND METHODS

A case-control study was carried out from January 2008 to February 2009; on 255 infertile men and 267 fertile men controls. Occupational exposure to certain chemical, physical and psychological workplace hazards was assessed by self-report questionnaire. General and andrological examination was conducted for all participants, however, semen analysis was done only for the infertile men cases, because the fertile men controls refused to give semen samples.

RESULTS

After adjustment of confounders, the results revealed that the following workplace exposure factors significantly increased the risk of male infertility: solvents and painting materials (OR: 3.88, 95% CI: 1.50-10.03), lead (OR: 5.43, 95% CI: 1.28-23.13), VDTs and computers (OR: 8.01, 95% CI: 4.03-15.87), shift work (OR: 3.60, 95% CI: 1.12-11.57) and work-related stress (fairly present: OR: 3.11, 95% CI: 1.85-5.24; often present: OR: 3.76, 95% CI: 1.96-7.52).

CONCLUSION

In spite of the limitations of this study, it supports other studies that raise the attention to minimize the exposure to the workplace hazards that may affect the fertility of male workers.

Stress and hormones

In the modern environment one is exposed to various stressful conditions. Stress can lead to changes in the serum level of many hormones including glucocorticoids, catecholamines, growth hormone and prolactin. Some of these changes are necessary for the fight or flight response to protect oneself. Some of these stressful responses can lead to endocrine disorders like Graves' disease, gonadal dysfunction, psychosexual dwarfism and obesity. Stress can also alter the clinical status of many preexisting endocrine disorders such as precipitation of adrenal crisis and thyroid storm.

Testosterone modulates pituitary vasotocin receptor expression and adrenal activity in osmotically stressed chicken

Regulation of arginine vasotocin (AVT), avian neurohypophyseal hormone, is an important component of the hypothalamo-pituitary-adrenal axis. Changes in plasma osmolality levels and sex steroids are known to affect AVT gene expression. The present study reports the effect of water deprivation and testosterone treatment independently, as well as simultaneously, on the pituitary vasotocin receptor VT2R expression and adrenal steroidogenic activity in sexually immature male chicken (Gallus gallus). Birds were divided into four groups- control, water deprived (WD), testosterone injected (TE) and TE treated water deprived (TE+WD). WD decreased and TE treatment alone or in combination with WD (TE+WD) increased VT2R expression compared to the control. Expression of pro-opiomelanocortin (POMC) was also studied since this gene is a polypeptide precursor of ACTH and is under the negative feedback of adrenal corticoids. TE treatment as well as WD separately or when coupled together decreased the POMC mRNA expression in the pituitary but stimulated adrenal steroidogenic activity. Further, VT2R expression decreased in TE+WD compared to TE group, but it was not different from the vehicle treated control group suggesting that the suppressive effect of WD on VT2R expression was inhibited by the stimulatory effect of testosterone. Similarly, although both TE and WD decreased POMC expression and increased steroidogenic activity, no further decrease or increase in these parameters was observed when these two (WD and TE) treatments were combined together. Although, the exact mechanism is not clear, data indicate a stimulatory action of testosterone on VT2R expression and adrenal function despite a decreased expression of POMC mRNA. Results also suggest that testosterone treatment to sexually immature birds, in addition to its effect on hypothalamic AVT neurons (earlier study) and pituitary VT2R expression (present study), masks or inhibits osmotic stress-induced alterations in pituitary-adrenal activity.

Chronic psychosocial stress alters NPY system: different effects in rat and tree shrew

The neuropeptide Y (NPY) system has been largely studied in relation to affective disorders, in particular for its role in the mechanisms regulating the pathophysiology of anxiety and depression and in the stress-related behaviours. Although NPY has been previously investigated in a variety of animal models of mood disorders, the receptor subtype mainly involved in the modulation of the stress response has not been identified. In the present study, the chronic psychosocial stress based on the resident-intruder protocol-an ethologically relevant paradigm known to induce behavioural and endocrine modifications which mimic depression-like symptoms-was used. Two different species were investigated: rat and tree shrew (Tupaia belangeri); the latter is regarded as an intermediate between insectivores and primates and it was chosen in this study for its pronounced territoriality. In these animals, the regulation of NPY and of Y(1), Y(2) and Y(5) receptors mRNA expression was evaluated after chronic stress and chronic antidepressant treatment by in situ hybridization in selected brain regions known to be involved in the pathophysiology of mood disorders. The animals were exposed to psychosocial stress for 35 days and concomitant daily fluoxetine treatment (10 mg/kg for rats and 15 mg/kg for tree shrews) after the first week of stress. The results confirmed a major role for hippocampal and hypothalamic NPY system in the pathophysiology of mood disorders. Although there were no evident differences between rat and tree shrew in the NPY system distribution, an opposite effect of chronic psychosocial stress was observed in the two species. Moreover, chronic antidepressant treatment was able to counteract the effects of stress and restored basal expression levels, suggesting the utility of these paradigms as preclinical models of stress-induced depression. Overall, although evident species differences were found in response to chronic psychosocial stress, the present study suggests a role for NPY receptors in the stress response and in the action of antidepressant drugs, providing further support for an involvement of this neuropeptidergic system in the pathophysiology of depression and anxiety.

Withania somnifera Improves Semen Quality in Stress-Related Male Fertility

Stress has been reported to be a causative factor for male infertility. Withania somnifera has been documented in Ayurveda and Unani medicine system for its stress-combating properties. However, limited scientific literature is available on this aspect of W. somnifera. We undertook the present study to understand the role of stress in male infertility, and to test the ability of W. somnifera to combat stress and treat male infertility. We selected normozoospermic but infertile individuals (N = 60), further categorized in three groups: normozoospermic heavy smokers (N = 20), normozoospermics under psychological stress (N = 20) and normozoospermics with infertility of unknown etiology (N = 20). Normozoospermic fertile men (N = 60) were recruited as controls. The subjects were given root powder of W. somnifera at a rate of 5 g/day for 3 months. Measuring various biochemical and stress parameters before and after treatment, suggested a definite role of stress in male infertility and the ability of W. somnifera to treat stress-related infertility. Treatment resulted in a decrease in stress, improved the level of anti-oxidants and improved overall semen quality in a significant number of individuals. The treatment resulted in pregnancy in the partners of 14% of the patients.

Effects of indoor air purification by an air cleaning system (Koala technology) on semen parameters in male factor infertility: results of a pilot study

A number of studies indicated a clear decline in semen quality in the past 30-50 years and there is accumulating evidence that this decline might result from exposure to high levels of air pollution. To examine the impact of environment on male reproductive ability, we undertook for the first time a pilot study on semen quality of infertile men exposed to purification of indoor air. Ten subjects with a history of unexplained male infertility and poor semen quality were exposed for at least 1 year to a cleaning indoor air system (Koala technology). The key feature of this air purifier is the unique innovative multiple filtering system. The treatment of total purification of indoor air showed neither improvements in semen parameters nor variation in reproductive hormones (P = N.S.), but induced an evident increase (P < 0.03 and more) in seminal leucocytic concentrations. Within the limits due to the small sample of subjects recruited, the sole purification of indoor air does not seem enough to improve semen quality, although the increase in leucocytic concentrations could indicate an activation of the role of immunosurveillance in a purified indoor air environment.

Effects of endurance exercise on the reproductive system of men: the "exercise-hypogonadal male condition"

An increasing number of investigative research studies point to participation in endurance exercise training as having significant detrimental effects upon reproductive hormonal profiles in men. Specifically, men chronically exposed to this type of exercise training exhibit persistently reduced basal (resting-state) free and total testosterone concentrations without concurrent LH elevations. Men displaying these symptoms have been deemed to exhibit the "exercise-hypogonadal male condition". The exact physiological mechanism inducing the reduction of testosterone in these men is currently unclear, but is postulated to be a dysfunction (or perhaps a readjustment) within the hypothalamic-pituitary-testicular regulatory axis. The potential exists for the reduced testosterone concentrations within exercise-hypogonadal men to be disruptive and detrimental to some anabolic-androgenic testosterone- dependent physiological processes. Findings on this point are limited, but do suggest spermatogenesis problems may exist in some cases. Alternatively, reductions in circulating testosterone concentrations could have cardiovascular protective effects and thus be beneficial to the health of these men. Present evidence suggests the exercise-hypogonadal condition is limited to men who have been persistently involved in chronic endurance exercise training for an extended period time (i.e., years), and it is not a highly prevalent occurrence (although, a thorough epidemiological investigation on the topic is lacking in the literature). Many questions regarding the male reproductive endocrine adaptive process to exercise training still remain unanswered, necessitating the need for much further investigation on the topic, especially with respect to the exercise-hypogonadal condition.

Paternal work stress and prolonged time to pregnancy

OBJECTIVE

The aim of this study was to explore an association between psychosocial stress at work in married men and their spouses' prolonged time to pregnancy (TTP).

METHODS

All married male workers of a large Korean petrochemical enterprise and their wives fulfilling the selection criteria were included. Main selection criteria were lack of use of contraceptives and experienced pregnancy in recent past. Data were available from 322 couples. Psychosocial stress at work was measured by the effort-reward imbalance questionnaire. Prolonged TTP was measured by the "TTP questionnaire".

RESULTS

After adjustment for confounding effects of demographic and life-style characteristics and benzene exposure, delayed TTP, defined by frequency of first-cycle pregnancy, was associated with one standard deviation (SD) increase of the effort-reward ratio in the chronically stressed group of married men (OR = 0.47; 95% CI = 0.22-0.99) in logistic regression analysis. A similar, but somewhat weaker effect, was found for the overall group (OR = 0.67; 95% CI = 0.47-0.94).

CONCLUSIONS

Paternal stress at work, as measured by effort-reward imbalance, seemed to be associated with a decreased number of conceptions in the first menstrual cycle.

Mucuna pruriens Reduces Stress and Improves the Quality of Semen in Infertile Men

The present investigation was undertaken to assess the role of Mucuna pruriens in infertile men who were under psychological stress. Study included 60 subjects who were undergoing infertility screening and were found to be suffering from psychological stress, assessed on the basis of a questionnaire and elevated serum cortisol levels. Age-matched 60 healthy men having normal semen parameters and who had previously initiated at least one pregnancy were included as controls. Infertile subjects were administered with M. pruriens seed powder (5 g day⁻¹) orally. For carrying out morphological and biochemical analysis, semen samples were collected twice, first before starting treatment and second after 3 months of treatment. The results demonstrated decreased sperm count and motility in subjects who were under psychological stress. Moreover, serum cortisol and seminal plasma lipid peroxide levels were also found elevated along with decreased seminal plasma glutathione (GSH) and ascorbic acid contents and reduced superoxide dismutase (SOD) and catalase activity. Treatment with M. pruriens significantly ameliorated psychological stress and seminal plasma lipid peroxide levels along with improved sperm count and motility. Treatment also restored the levels of SOD, catalase, GSH and ascorbic acid in seminal plasma of infertile men. On the basis of results of the present study, it may be concluded that M. pruriens not only reactivates the anti-oxidant defense system of infertile men but it also helps in the management of stress and improves semen quality.

Testosterone and endurance exercise: development of the "exercise-hypogonadal male condition"

During the last 30 years a large number of research studies have been conducted examining reproductive endocrine dysfunction in exercising women. The number of similar studies examining men is still relatively small. Nevertheless, an increasing amount of research studies in men indicate endurance exercise training has significant effects upon the major male reproductive hormone, testosterone, and the hypothalamic-pituitary-testicular axis that regulates reproductive hormones. This review article addresses one reproductive endocrine dysfunction found in exercising men, what has been deemed the "exercise-hypogonadal male condition". Specifically, men with this condition exhibit basal (resting-state) free and total testosterone levels that are significantly and persistently reduced. The exact physiological mechanism inducing the reduction of testosterone is currently unclear, but is postulated to be a dysfunction (or perhaps a readjustment) within the hypothalamic-pituitary-testicular regulatory axis. The time course for the development of the "exercise-hypogonadal condition" or the threshold of exercise training necessary to induce the condition remains unresolved. The potential exists for these reduced testosterone levels within the exercise-hypogonadal male to disrupt and be detrimental to some anabolic or androgenic testosterone-dependent physiological processes. Unfortunately, extremely few research studies have addressed whether such processes are affected, and thus findings are inconclusive. Conversely, the alterations in testosterone levels brought about by endurance exercise training have the potential for cardiovascular protective effects and thus could be beneficial to the health of these men. Current evidence suggests this condition is limited to men who have been persistently involved in chronic endurance exercise training for extended periods of time (i.e., years). Many questions, however, regarding the male reproductive endocrine adaptive process to exercise and exercise training remain unanswered, necessitating the need for further research on this topic.