Decline in seminal quality in Indian men over the last 37 years

Background

Since the first report of a decline in semen quality in 1974, there have been several reports of similar declines across populations. Despite some scattered reports of declining semen quality in the Indian sub-continent, comprehensive studies analyzing semen quality over the last few decades have not been undertaken. We undertook the present study to investigate the temporal trend in semen parameters in Indian populations over a period of 37 years (1979–2016).

Methods

Publications providing semen analysis details for fertile and infertile men from the Indian sub-continent were collected by a thorough literature search. Semen quality data for 6466 normal fertile or presumptive normal men (from 119 studies/data sets) and 7020 infertile men (from 63 studies/data sets) published between 1979 and 2016 were retrieved. We undertook systematic review and quantitative analysis of mean sperm count, motility, normal morphology and other available parameters. Data were analyzed to estimate semen parameters reference values for Indian men and to assess temporal trends in infertile, fertile and all subjects.

Results

Seminal quality shows a decreasing temporal trend and the decrease is higher in infertile than fertile males. In pooled analysis for all individuals, significant (p?<?0.05 or?<?0.001) declines in sperm concentration and normal morphology are observed; however, isolated analysis for each group shows declines without statistical significance. The mean (± SD) semen volume, sperm concentration, total motility, rapid linear progressive motility, normal sperm morphology and sperm viability for Indian fertile men are 2.88?±?0.77 ml, 81.08?±?29.21 million/ml, 66.37?±?10.95%, 52.64?±?15.78%, 56.68?±?20.23% and 72.63?±?8.31%, respectively, whereas in infertile these are 3.07?±?1.27 ml, 37.94?±?26.41 million/ml, 40.22?±?13.76%, 26.79?±?15.47%, 36.41?±?21.66% and 55.25?±?11.99%, respectively. The mean seminal parameter values were significantly lower (p?<?0.001) in infertile as compared to fertile men, except semen volume.

Conclusions

Semen parameters in Indian men have declined with time and the deterioration is quantitatively higher in the infertile group. The study also provides reference values for semen parameters in Indian men.

     

Predictive value of sperm deoxyribonucleic acid (DNA) fragmentation index in male infertility

Background

Recently, damage to the sperm DNA has been studied as it is associated with reduced fertilization rates, embryo quality, and pregnancy rates, also higher rates of spontaneous miscarriage.

Objective

To develop a diagnostic method in predicting male infertility.

Material and Methods

The design of this study is cross-sectional. Data were retrieved from medical records of Yasmin IVF Clinic Dr. Cipto Mangunkusumo General Hospital and Daya Medika Infertility Clinic from January to December 2015. Subjects were selected by consecutive sampling and divided into two groups: infertile and fertile. Sperm deoxyribonucleic acid fragmentation index (DFI) was determined by sperm chromatin dispersion (SCD) method using Halosperm® Kit.

Results

There were 114 subjects (36 fertile and 78 infertile) selected into this study. We found no significant difference in the age between both of groups. The median value of sperm DFI in infertile group was significantly higher, 29.95 (26.6–34.3)%, compared to 19.90 (15.6–24.4)% of the fertile group, with p?<?0.001. Area Under Curve (AUC) of sperm DFI, 0.862 (95% CI 0.783, 0.941), was higher than concentration (AUC 0.744; 95% CI 0.657, 0.831), motility (AUC 0.668; 95% CI 0.572, 0.765), and morphology (AUC 0.718; 95% CI 0.697, 0.864) of the semen analysis. At the cut-off point of 26.1%, the sperm DFI had sensitivity of 80.8% (95% CI; 70.0, 88.5), specificity of 86.1% (95% CI; 69.7, 94.8), positive predictive value (PPV) of 92.6% (95% CI; 83.0, 97.3), negative predictive value (NPV) of 67.4% (95% CI; 51.9, 80.0), positive likelihood ratio (PLR) of 12.6 (95% CI; 5.4, 29.4), and negative likelihood ratio (NLR) of 0.48 (95% CI 0.31, 0.75). Sperm DFI of ≥26.1% had prevalence ratio of 2.84 (95% CI 1.86, 4.33) for the occurrence of male infertility.

Conclusion

There was significant difference between the median value of sperm DFI of infertile men and fertile men. Compared to semen analysis, sperm DFI at cut-off point of 26.1% has a higher diagnostic value (AUC).

     

Le sperme « inflammatoire »: ses relations avec la fertilité

Objectives

Sperm inflammation is caused by bacterial or viral infection of the male genitourinary tract; it is often clinically asymptomatic. There is a dilemma about the causal relationship between leukocytes as markers of inflammation and poor semen quality. We were interested in sperm changes at molecular level caused by inflammation.

Material and methods

This study was based on a literature review and personal data. In 200 male partners of infertile couples with normal semen analysis, the percentage of sperm with DNA denaturation and the level of reactive oxygen species (ROS) were determined by flow cytometric analysis, after acridine orange and dihydroethidium stainings, and correlated with seminal plasma elastase levels.

Results

In the literature, a positive relationship between inflammation and increased sperm apoptosis was found with increased necrosis and decreased mitochondrial membrane potential. We found a positive correlation between the percentage of sperm with denatured DNA and elastase levels. The percentage increased from 8.6% at elastase level 0–100 μg/l to 15.7% at elastase level 100–250 μg/l; this increase was not dependent on ROS production. The percentage of sperm with denatured DNA normalized at elastase levels above 600 μg/l.

Discussion and conclusion

Changes in sperm DNA or membranes do not necessarily affect classical semen characteristics or reduce fertility in males. They can, however, have a negative effect on capacitation and acrosomal reaction, resulting in failed fertilization or poor embryo development. Before treatment, we must take into account the location and the duration of the inflammation as well as the damage done to sperm.     

In Vitro fertilization failure of normozoospermic men: search for a lack of testicular isozyme of angiotensin-converting enzyme

Background

Angiotensin converting enzyme (ACE) is a metalloprotease with two isoforms. The somatic isoform is a key component of the renin-angiotensin system; its main function is to hydrolyse angiotensin I into angiotensin II. The germinal or testicular isoform (tACE) located at the plasma membrane of the spermatozoa, plays a crucial role in the spermatozoa-oocyte interaction during in vivo fertilization, in rodents. Disruption of the tACE in mice has revealed that homozygous male tACE?/? sire few pups despite mating normally. Few spermatozoa from these tACE?/? mice are bound to the zona pellucida (ZP) despite normal semen parameters. Based on these findings in mice models, we hypothesized that some infertile men that have the same phenotype as the tACE?/? mice, ie normal semen parameters and a lack of sperm bind to the ZP in vitro, may have a tACE defect.

Methods

Twenty four men participated to this study. The case subjects (n?=?10) had normal semen parameters according to the WHO guidelines (WHO 1999) but a total in vitro fertilization failure with absence of sperm fixation to the ZP. The control subjects (n?=?14) also had normal semen parameters and a normal fertilization rate ≥65%. We investigated the tACE expression in spermatozoa by Western-Blot and performed a DNA sequencing of the tACE gene.

Results

Three case-subjects and one control-subject had no tACE expression. There were no statistic differences between the two groups. No mutation was detected in the tACE DNA sequence.

Conclusions

Our results didn’t show any involvement of tACE in human fertilization especially in ZP binding.     

The relationship between anogenital distance, fatherhood, and fertility in adult men

Background

Anogenital distance (AGD), a sexually dimorphic measure of genital development, is a marker for endocrine disruption in animal studies and may be shorter in infant males with genital anomalies. Given the correlation between anogenital distance and genital development, we sought to determine if anogenital distance varied in fertile compared to infertile adult men.

Methods

A cross sectional study of consecutive men being evaluated for infertility and men with proven fertility was recruited from an andrology clinic. Anogenital distance (the distance from the posterior aspect of the scrotum to the anal verge) and penile length (PL) were measured using digital calipers. ANOVA and linear regression were used to determine correlations between AGD, fatherhood status, and semen analysis parameters (sperm density, motility, and total motile sperm count).

Findings

A total of 117 infertile men (mean age: 35.3±17.4) and 56 fertile men (mean age: 44.8±9.7) were recruited. The infertile men possessed significantly shorter mean AGD and PL compared to the fertile controls (AGD: 31.8 vs 44.6 mm, PL: 107.1 vs 119.5 mm, p<0.01). The difference in AGD persisted even after accounting for ethnic and anthropomorphic differences. In addition to fatherhood, on both unadjusted and adjusted linear regression, AGD was significantly correlated with sperm density and total motile sperm count. After adjusting for demographic and reproductive variables, for each 1 cm increase in a man''s AGD, the sperm density increases by 4.3 million sperm per mL (95% CI 0.53, 8.09, p = 0.03) and the total motile sperm count increases by 6.0 million sperm (95% CI 1.34, 10.58, p = 0.01). On adjusted analyses, no correlation was seen between penile length and semen parameters.

Conclusion

A longer anogenital distance is associated with fatherhood and may predict normal male reproductive potential. Thus, AGD may provide a novel metric to assess reproductive potential in men.     

Functional claudication distance: a reliable and valid measurement to assess functional limitation in patients with intermittent claudication

Background

Pharmacological inhibition of endothelial arginase-II has been shown to improve endothelial nitric oxide synthase (eNOS) function and reduce atherogenesis in animal models. We investigated whether the endothelial arginase II is involved in inflammatory responses in endothelial cells.

Methods

Human endothelial cells were isolated from umbilical veins and stimulated with TNFα (10 ng/ml) for 4 hours. Endothelial expression of the inflammatory molecules i.e. vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin were assessed by immunoblotting.

Results

The induction of the expression of endothelial VCAM-1, ICAM-1 and E-selectin by TNFα was concentration-dependently reduced by incubation of the endothelial cells with the arginase inhibitor L-norvaline. However, inhibition of arginase by another arginase inhibitor S-(2-boronoethyl)-L-cysteine (BEC) had no effects. To confirm the role of arginase-II (the prominent isoform expressed in HUVECs) in the inflammatory responses, adenoviral mediated siRNA silencing of arginase-II knocked down the arginase II protein level, but did not inhibit the up-regulation of the adhesion molecules. Moreover, the inhibitory effect of L-norvaline was not reversed by the NOS inhibitor L-NAME and L-norvaline did not interfere with TNFα-induced activation of NF-κB, JNK, p38mapk, while it inhibited p70s6k (S6K1) activity. Silencing S6K1 prevented up-regulation of E-selectin, but not that of VCAM-1 or ICAM-1 induced by TNFα.

Conclusion

The arginase inhibitor L-norvaline exhibits anti-inflammatory effects independently of inhibition of arginase in human endothelial cells. The anti-inflammatory properties of L-norvaline are partially attributable to its ability to inhibit S6K1.     

Mitochondrial DNA mutations and polymorphisms in asthenospermic infertile men

In this study we performed a systematic sequence analysis of 6 mitochondrial genes (cytochrome oxidase I, cytochrome oxidase II, cytochrome oxidase III, adenosine triphosphate synthase6, ATP synthase8, and cytochrome b] in 66 infertile men suffering from asthenospermia (n = 34) in comparison to normospermic infertile men (n = 32) and fertile men (n = 100) from Tunisian population. A total of 72 nucleotide substitutions in blood cells mitochondrial DNA were found; 63 of them were previously identified and reported in the human mitochondrial DNA database (www.mitomap.org) and 9 were novel. We also detected in 3 asthenospermic patients a novel heteroplasmic missense mitochondrial mutation (m.9387 G>A) in COXIII gene (8.8 %) that was not found in any of normospermic infertile and fertile men. This mutation substituting the valine at position 61 to methionine in a conserved amino acid in the transmembrane functional domain of the polypeptide, induces a reduction of the hydropathy index (from +1.225 to +1.100) and a decrease of the protein 3D structures number (from 39 to 32) as shown by PolyPhen bioinformatic program.     

Profil spermiologique de l’époux dans les couples infertiles en milieu négro-africain au Sénégal

Objective

To define the role of male infertility in black African couples in Senegal and to establish the semen profile.

Material and Methods

We analysed 17,459 sperm counts and 5,563 post-coital tests from patients consulting for primary or secondary infertility between January 1982 and December 2002. Negative and deficient sperm counts of post-coital tests were studied to demonstrate the responsibility of male infertility. For sperm counts, we studied the patient’s age, the mode of semen collection, the volume of ejaculate and semen characteristics.

Results

Primary sterility (68.4%) was twice as frequent as secondary sterility (31.6%). Male infertility (31.7%) was twice as frequent as female infertility (14.7%). Twenty eight per cent of patients presented hypospermia. Isolated oligozoospermia was observed in 10% of cases and azoospermia was detected in 23% of cases. Qualitative sperm changes were observed in 44.3% of cases. A positive semen culture was reported in 21.3% of cases. Combinations (qualitative sperm changes and abnormalities of number) were observed in 43.4% of cases. Oligo-astheno-teratozoospermia (OATS) with spermatozoa with an elongated head, cytoplasmic remnants and angulation, characteristic of varicocele was significantly more frequent in patients with varicocele (97% of men with right varicocele and 98.2% of men with bilateral varicocele). Reactive epididymosemino-prostatic dystrophy was observed in 11.9% of cases

Conclusion

Male infertility plays a real role. The semen profile of the husband of a sterile couple in Senegal is characterized by the importance of polymorphic alterations such as oligo-astheno-teratospermia and secretory azoospermia.     

Aspects cliniques et biologiques de l’azoospermie chez l’homme infertile en Tunisie

Objective

It is now very important to investigate azoospermia because the introduction of the intracytoplasmic sperm injection technique during the last decade has allowed many infertile men to achieve their dreams of fatherhood. The purpose of this study was to define the characteristics of infertile men with azoospermia, and to analyse the clinical and laboratory features and the causes of infertility in Tunisia. The authors also discuss various aspects that they consider to be very important in the diagnosis of male fertility.

Material and Methods

This retrospective study analysed the parameters of physical examination, laboratory tests, semen analysis, radiographic examinations, testicular biopsy, karyotype and AZF microdeletions.

Results

Based on the results of endocrinological and cytogenetic examinations, the aetiology of azoospermia was considered to be secretory in 43 cases of azoospermia. Physical examination revealed a high percentage of hypotrophic/atrophic testes (43.9%). Serum follicle stimulating hormone levels were high in 58.5% of cases. The overall incidence of chromosomal abnormalities was 31.4%. The most frequent anomaly was Klinefelter syndrome (9 cases). Seven out of 28 patients (25%) with nonobstructive azoospermia had AZF deletions. None of the patients with excretory azoospermia and severe oligospermia had an abnormal karyotype or AZF microdeletions. 48.8% of patients presented a varicocele, 13.9% had cryptorchidism and 13.0% had a history of genital tract infection.

Conclusion

In line with the literature, genetic abmormalities are the main causes of severe forms of impaired spermatogenesis in the Tunisian population.     

Relationship between Semenogelins bound to human sperm and other semen parameters and pregnancy outcomes

Background

Semenogelins (SEMGs) are major components of human seminal vesicle secretions. Due to SEMG’s sperm-motility inhibitor, a significant negative correlation between sperm motility and the proportion of SEMG-bound spermatozoa (SEMG+) was found in asthenozoospermic patients. SEMGs also show intrinsic inhibitory capability for sperm capacitation; however, studies on actual clinical specimens have not been conducted.

Methods

To reveal the relationship between SEMGs and the fertilizing capacity of sperm from male infertile patients who are not restricted to asthenozoospermia, we measured the proportion of SEMG+ in the spermatozoa of 142 male infertile patients. The pregnancy outcomes in partners of these patients were retrospectively analyzed using questionnaires.

Results

Among examined semen parameters, only the total SEMG-unbound sperm count showed a tendency to be different between the spontaneous pregnancy or intra-uterine-insemination-pregnancy groups and in-vitro-fertilization- or intracytoplasmic-sperm-injection-pregnancy groups. It was elevated in the former group, which includes patients who used in vivo fertilization.

Conclusions

The total SEMG-unbound sperm count would be a relevant parameter for in vivo fertilization. This result suggests that SEMGs inhibit ectopic capacitation before sperm reach the fertilization site and that the number of total SEMG-unbound sperm is a parameter directly linked to the possibility of in vivo fertilization.

     

Treatment with the arginase inhibitor Nw-hydroxy-nor-L-arginine restores endothelial function in rat adjuvant-induced arthritis

Introduction

Endothelial dysfunction (ED) participates to atherogenesis associated to rheumatoid arthritis. We recently reported increased arginase activity/expression in vessels from adjuvant-induced arthritis (AIA) rats. In the present study, we investigated the effects of a curative treatment with the arginase inhibitor N_w-hydroxy-nor-L-arginine (nor-NOHA) on vascular dysfunction in AIA rats.

Methods

AIA rats were treated with nor-NOHA (40 mg/kg/d, ip) for 21 days after the onset of arthritis. A group of untreated AIA rats and a group of healthy rats served as controls. ED was assessed by the vasodilatory effect of acetylcholine (Ach) on aortic rings. The role of superoxide anions, prostanoids, endothelium-derived hyperpolarizing factor (EDHF) and nitric oxide synthase (NOS) pathway was studied. Plasma levels of IL-6 and vascular endothelial growth factor (VEGF) were determined by ELISA kits. Arthritis severity was estimated by a clinical, radiological and histological analysis.

Results

Nor-NOHA treatment fully restored the aortic response to Ach to that of healthy controls. The results showed that this beneficial effect is mediated by an increase in NOS activity and EDHF and reduced superoxide anion production as well as a decrease in the activity of cyclooxygenase (COX)-2, thromboxane and prostacyclins synthases. In addition, nor-NOHA decreased IL-6 and VEGF plasma levels in AIA rats. By contrast, the treatment did not modify arthritis severity in AIA rats.

Conclusions

The treatment with an arginase inhibitor has a potent effect on ED in AIA independently of the severity of the disease. Our results suggest that this new pharmacological approach has the potential as a novel add-on therapy in the treatment of RA.     

The Role of Arginine–Nitric Oxide Pathway in Patients with Alzheimer Disease

There is a reciprocal regulation of arginase and nitric oxide synthase in l-arginine-metabolizing pathways. There are various evidences of the role of nitric oxide in several neuropsychiatric disorders including Alzheimer’s disease. However, there is no study that has investigated the role of arginase as an important part of the arginine regulatory system affecting nitric oxide synthase activity in Alzheimer’s disease. This study aims to investigate arginase, manganese (a cofactor of arginase), and total nitrite levels (a metabolite of NO) and their relationship to the arginine–NO pathway in patients with Alzheimer’s disease. Arginase activities, Mn, and total nitrite levels were measured in plasma from 47 patients with Alzheimer’s disease and 43 healthy control subjects. Plasma arginase activities and manganese were found to be significantly lower and total nitrite level higher in patients with Alzheimer’s disease compared with controls. Our results suggest that the arginine–NO pathway is involved in the pathogenesis of Alzheimer’s disease.     

Effects of Dietary Zinc and l-Arginine Supplementation on Total Antioxidants Capacity, Lipid Peroxidation, Nitric Oxide, Egg Weight, and Blood Biochemical Values in Japanase Quails

The aim of this study was to evaluate effects of dietary zinc and l-arginine supplementation on blood total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), some blood chemistry parameters, and egg weights of laying quails. Three groups of Japanese quails were fed with a diet containing l-arginine (5 mg/kg), zinc (60 mg/kg), and normal basal diet (control) for 30 days. TAC, lipid peroxidation, and biochemical analysis were performed in the blood of animals. l-Arginine and zinc supplementation improved TAC and reduced MDA concentrations compared to the control (P?<?0.05). In comparison to the control, blood NO concentrations were increased by l-arginine (P?<?0.01) and zinc treatment (P?<?0.05). Both zinc (P?<?0.001) and l-arginine (P?<?0.01) supplementation significantly increased egg weight in laying quails. Some of the blood chemistry parameters were also altered by the treatment of l-arginine and zinc supplementation. No difference was found in blood albumin and creatinine levels among the groups. Blood glucose (P?=?0.833) and total protein (P?=?0.264) levels in control and l-arginine-treated groups were found to be similar. Glucose and total protein levels were decreased in zinc-supplemented animals compared to the control and l-arginine groups (P?<?0.05). No difference was found in triglyceride levels between control and zinc-applied groups (P?=?0.197). However, l-arginine treatment reduced the blood triglyceride levels compared to the control (P?<?0.05). In conclusion, l-arginine and zinc supplementation could be beneficial and effective for decreasing oxidative stress, boosting antioxidant capacity, and improving egg weight in the blood of the animals.     

Analyse du statut oxydatif spermatique chez des patients infertiles

Introduction

Male infertility constitutes public health problems. Several factors are at the origin of this phenomenon. Currently, the oxidative stress is accused to be one of the leading causes. In our study, we sought a correlation between the markers of the oxidative stress and the sperm characteristics (morphology).

Material and methods

We evaluated the antioxidant status in the seminal plasma of 129 infertile men. Patients were characterized by infertility of variable duration. They were divided into four groups: normozoospermics who were considered as controls (n=34), asthenozoospermics (Astheno; n=43), oligozoospermics (Oligo; n=22) and teratozoospermics (Terato; n=30). Among the oxidative stress markers, we evaluated, in seminal plasma, zinc, calcium, magnesium and selenium by spectrophotometry of atomic absorption to flame and furnace. The malondialdehyde (MDA) is proportioned by spectrofluorometry.

Results

Our results show that the seminal concentrations of zinc and selenium are higher in the control group than the concentrations of these same elements in the three other groups. The seminal zinc concentration was significantly correlated with the sperm count (r=0.49; p < 0.001) and MDA (r=- 0.35; p<0.05). Sperm motility was correlated with calcium (r=0.41; p<0.001) and magnesium (r=0.31; p<0.05). The MDA concentration is higher in the three groups of patients: oligozoospermics (3.22±1.37 ??g/ml), asthenozoospermics (3.52±1.93 ??g/ml) and teratozoospermics (3.64±1.73 ??g/ml) compared with controls (2.32±0.94 ??g/ml). A single positive correlation was observed between the MDA and morphology (r=0.19; p<0.05).

Conclusion

Our study confirms that the oxidative stress plays an important role in the process of deteriorations of the spermatozoa. The free radicals can, indeed, modify the membrane structure as well as the membrane structure of the deoxyribonucleic acid. These deteriorations also lead to an increase in the percentage of sperm of abnormal forms.     

Les larges vacuoles des têtes spermatiques sont-elles associées à des altérations du noyau ou de l’acrosome du spermatozoïde ?

Objective

The aim of this study was to detect acrosome and nucleus alterations in isolated spermatozoa with large vacuoles detected by MSOME (Motile Sperm Organelle Morphology Examination), named type 3 spermatozoa and defined by the presence of one or more vacuoles occupying more than 13% of the sperm head area.

Material and methods

Twenty infertile men were included in this study. Whole sperm and isolated spermatozoa were compared. Spermatozoa acrosome and nucleus were explored using 1) proacrosin immunostaining with a monoclonal antibody (4D4), 2) DNA fragmentation with TUNEL assay, 3) chromatin condensation with aniline blue staining, and 4) aneuploidy after fluorescence in situ hybridization (FISH) and analysis by electron transmission and confocal microscopy.

Results

Acrosome abnormalities were significantly increased in type 3 spermatozoa compared towhole sperm(77.8 ± 2.49% vs. 70.6 ± 2.62%). DNA fragmentation was similar in type 3 spermatozoa compared towhole sperm(14.5 ± 3.45%vs. 11.5 ± 1.25%). Chromatin condensation was significantly altered in isolated spermatozoa as well as aneuploidy frequencies (50.4 ± 3.10% vs. 26.5 ± 2.60% and 7.8 ± 1.98% vs. 1.3 ± 0.18%). Large vacuoles have an exclusive nuclear location, confirmed by electron and confocal microscopy.

Conclusion

Large vacuoles are probably due to sperm nucleus maturation dysfunction during spermiogenesis.     

Carbon monoxide affects electrical and contractile activity of rat myocardium

Background

Carbon monoxide (CO) is a toxic gas, which also acts in the organism as a neurotransmitter. It is generated as a by-product of heme breakdown catalyzed by heme oxygenase. We have investigated changes in electrical and contractile activity of isolated rat atrial and ventricular myocardium preparations under the influence of CO.

Methods

Standard microelectrode technique was used for intracellular registration of electrical activity in isolated preparations of atrial and ventricular myocardium. Contractions of atrial myocardial stripes were registered via force transducer.

Results

CO (10^-4 - 10^-3 M) caused prominent decrease of action potential duration (APD) in working atrial myocardium as well as significant acceleration of sinus rhythm. In addition CO reduced force of contractions and other parameters of contractile activity. Inhibitor of heme oxygenase zinc protoporphyrin IX exerts opposite effects: prolongation of action potential, reduction of sinus rhythm rate and enhancement of contractile function. Therefore, endogenous CO, which may be generated in the heart due to the presence of active heme oxygenase, is likely to exert the same effects as exogenous CO applied to the perfusing medium. In ventricular myocardium preparations exogenous CO also induced shortening of action potential, while zinc protoporphyrin IX produced the opposite effect.

Conclusions

Thus, endogenous or exogenous carbon monoxide may act as an important regulator of electrical and contractile cardiac activity.     

Arginase attenuates inhibitory nonadrenergic noncholinergic nerve-induced nitric oxide generation and airway smooth muscle relaxation

Background

Recent evidence suggests that endogenous arginase activity potentiates airway responsiveness to methacholine by attenuation of agonist-induced nitric oxide (NO) production, presumably by competition with epithelial constitutive NO synthase for the common substrate, L-arginine. Using guinea pig tracheal open-ring preparations, we now investigated the involvement of arginase in the modulation of neuronal nitric oxide synthase (nNOS)-mediated relaxation induced by inhibitory nonadrenergic noncholinergic (iNANC) nerve stimulation.

Methods

Electrical field stimulation (EFS; 150 mA, 4 ms, 4 s, 0.5 – 16 Hz)-induced relaxation was measured in tracheal preparations precontracted to 30% with histamine, in the presence of 1 μM atropine and 3 μM indomethacin. The contribution of NO to the EFS-induced relaxation was assessed by the nonselective NOS inhibitor L-NNA (0.1 mM), while the involvement of arginase activity in the regulation of EFS-induced NO production and relaxation was investigated by the effect of the specific arginase inhibitor nor-NOHA (10 μM). Furthermore, the role of substrate availability to nNOS in EFS-induced relaxation was measured in the presence of various concentrations of exogenous L-arginine.

Results

EFS induced a frequency-dependent relaxation, ranging from 6.6 ± 0.8% at 0.5 Hz to 74.6 ± 1.2% at 16 Hz, which was inhibited with the NOS inhibitor L-NNA by 78.0 ± 10.5% at 0.5 Hz to 26.7 ± 7.7% at 8 Hz (P < 0.01 all). In contrast, the arginase inhibitor nor-NOHA increased EFS-induced relaxation by 3.3 ± 1.2-fold at 0.5 Hz to 1.2 ± 0.1-fold at 4 Hz (P < 0.05 all), which was reversed by L-NNA to the level of control airways in the presence of L-NNA (P < 0.01 all). Similar to nor-NOHA, exogenous L-arginine increased EFS-induced airway relaxation (P < 0.05 all).

Conclusion

The results indicate that endogenous arginase activity attenuates iNANC nerve-mediated airway relaxation by inhibition of NO generation, presumably by limiting L-arginine availability to nNOS.     

Impact de la varicocélectomie chez les patients ayant une azoospermie non obstructive ou une oligozoospermie sévère

Objective

To evaluate the changes induced by retroperitoneal varicocelectomy on infertile men with nonobstructive azoospermia or severe oligozoospermia.

Patients and methods

The records were retrospectively evaluated for 46 infertile men with severe oligozoospermia (group I) and 15 infertile men with non-obstructive azoospermia (group II). The parameters of sperm before and after surgery and unassisted pregnancy rate were comparatively analysed.

Results

In the severe oligozoospermia group, the mean age of patients was 35.5 ± 6.4 (23–47 years). The mean duration of infertility was 4.9 ± 3.4 years (1–13 years). Of these patients, 41(89.1%) had bilateral varicocele and five (10.9%) had unilateral left-side varicocele. The varicocele was classified as grade I in two cases (4.3%), grade II in 39 cases (84.7%) and grade III in five cases (10.9%). After surgery, the mean sperm count increased from 1.85 ± 1.4 to 8.3 ± 10.3 millions/ml and mean sperm normal motility from 43.3 ± 21.5 to 47.6 ± 29.2%. The mean sperm abnormal morphology decreased from 65.05 ± 21.6 to 50.08 ± 26.9%. After a mean follow-up of 26.2 ± 11.6 months, the unassisted pregnancy rate in this group was 26.1%. In the non-obstructive azoospermia group (N = 15), the mean age of patients was 40.8 ± 7.2 (27–47 years). The mean duration of infertility was 6 ± 3.1 years (3–15 years). After varicocelectomy, an induction of spermatogenesis was observed in three patients (20%) with presence of motile sperm in the ejaculate. In this group, only one of the 15 men achieved unassisted pregnancy.

Conclusion

Retroperitoneal varicocele repair resulted in spermatogenesis induction with presence of motile ejaculated spermatozoa for some men with non-obstructive azoospermia. It induced spermatogenesis and fertility enhancement in men with severe oligozoospermia. Varicocele repair should be considered in men with non-obstructive azoospermia or severe oligozoospermia.