Moment of induction and duration of experimental varicocele in rats: effects on semen quality

ABSTRACT Purpose Varicocele is a condition known to cause damage to seminal parameters and sperm function. Furthermore, it has been hypothesized that the varicocele effect on fertility is time-dependent; however, little is known about the consequences of its establishment time on reproductive organs and/or sperm function. This study aimed to evaluate the effect of the duration of experimental varicocele on reproductive organs, sperm parameters, and sperm function. Materials and Methods Varicocele induction surgeries were performed in Wistar rats aged 40 or 100 days old. At 160-day-old, analyses were performed, including biometry of reproductive organs (prostate, seminal vesicles, epididymis, and testis), sperm parameters (vitality, morphology, and motility), and sperm function tests (nuclear DNA integrity, acrosome integrity, and mitochondrial activity). Results The analysis of the biometry of reproductive organs showed no differences between distinct ages in which varicocele was induced. The total abnormal sperm morphology was bigger in animals with varicocele induced to 100 days old than in animals with varicocele induced to 40 days old. Regarding nuclear DNA integrity, animals of varicocele induced to 100 days old showed worse results compared to animals of varicocele induced to 40 days old. Other parameters analyzed showed no differences between varicocele groups. Conclusion In this study conducted on rats, we conclude that varicocele adversely affects sperm, particularly its function. However, we did not observe a negative progressive effect on sperm.

Moment of induction and duration of experimental varicocele in rats: effects on semen quality.

PURPOSE: Varicocele is a condition known to cause damage to seminal parameters and sperm function. Furthermore, it has been hypothesized that the varicocele effect on fertility is time-dependent; however, little is known about the consequences of its establishment time on reproductive organs and/or sperm function. This study aimed to evaluate the effect of the duration of experimental varicocele on reproductive organs, sperm parameters, and sperm function. MATERIALS AND METHODS: Varicocele induction surgeries were performed in Wistar rats aged 40 or 100 days old. At 160-day-old, analyses were performed, including biometry of reproductive organs (prostate, seminal vesicles, epididymis, and testis), sperm parameters (vitality, morphology, and motility), and sperm function tests (nuclear DNA integrity, acrosome integrity, and mitochondrial activity). RESULTS: The analysis of the biometry of reproductive organs showed no differences between distinct ages in which varicocele was induced. The total abnormal sperm morphology was bigger in animals with varicocele induced to 100 days old than in animals with varicocele induced to 40 days old. Regarding nuclear DNA integrity, animals of varicocele induced to 100 days old showed worse results compared to animals of varicocele induced to 40 days old. Other parameters analyzed showed no differences between varicocele groups. CONCLUSION: In this study conducted on rats, we conclude that varicocele adversely affects sperm, particularly its function. However, we did not observe a negative progressive effect on sperm.

Understanding the impact of varicocele on sperm capacitation.

OBJECTIVE: To study the relationship between the seminal sample quality of men with varicocele and sperm capacitation. DESIGN: Cross-sectional observational study. SETTING: Academic hospital. PATIENT(S): Seventy-six men (19 control and 57 with varicocele) were analyzed. INTERVENTION(S): Semen samples were submitted to a discontinuous density gradient for sperm selection. Sperm capacitation was induced using a human tubal fluid medium supplemented with bovine serum albumin. MAIN OUTCOME MEASURE(S): After capacitation induction, the sperm were assessed by capacitation state, computer-assisted sperm motility, mitochondrial activity, membrane integrity, acrosome reaction, and intracellular oxidative stress. RESULT(S): The capacitation period increased sperm motility, showing an increase in the average path velocity and a decrease in the straightness compared with sperm before capacitation (paired analysis). After capacitation, the rate of capacitated sperm, motility, and mitochondrial activity showed differences between groups (control and varicocele). The varicocele group showed lower mitochondrial activity and capacitation than the control group. On the other hand, no significant differences were observed in the other variables evaluated. CONCLUSION(S): Varicocele men showed less viable sperm and mitochondrial activity than control men after capacitation sperm. The induction of capacitation altered motility by increasing path velocity and decreasing straightness in all of the studied groups, evidencing the occurrence of hyperactivation.

Carnosine treatment during human semen processing by discontinuous density gradient.

The aim of this article was to evaluate the effects of different concentrations of carnosine added during human semen processing. Semen samples from 34 patients were submitted to processing by discontinuous density gradient centrifugation without (control) or with different concentrations of carnosine supplementation as follows: (a) 20 mM of carnosine supplementation on the layers of Percoll; and (b) 50 mM carnosine supplementation. Sperm samples were then washed with human tubal fluid medium and evaluated according to sperm kinetics and functional assessment. For statistical analysis, data were evaluated by a general linear model or a Friedman test, whenever appropriate. The 50 mM carnosine supplementation led to improved sperm mitochondrial activity when compared to untreated samples. Motility variables, such as percentage of motile and progressively motile spermatozoa, average path velocity, straight line velocity, curvilinear velocity and linearity, showed an improvement after semen processing irrespective of carnosine supplementation. Both concentrations of carnosine increased the beat-cross frequency (BCF) when compared to samples before processing. We conclude that carnosine supplementation in semen samples benefits sperm mitochondrial activity and BCF.

One day is better than four days of ejaculatory abstinence for sperm function.

According to the World Health Organization guidelines, ejaculatory abstinence (EA) of 2-7 days is recommended for semen analysis. This study aimed to determine how seminal quality may be affected by two EA periods from the same man. Seminal samples from 65 men were evaluated by conventional semen analysis and qualitative characteristics after 1 and 4 days of EA (two samples/man). The semen was qualitatively analyzed by examining oxidative activity (intracellular and seminal plasma), sperm function (acrosome integrity, mitochondrial activity, and nuclear DNA integrity), and epididymal function. As expected, samples collected after 1 day of EA showed a decrease in volume and sperm total number compared to samples collected after 4 days of EA. The sperm motility of the samples collected after 1 day of EA was better compared to samples collected after 4 days of EA. Oxidative activity measured was lower after 1 day of EA compared with those measured after 4 days of EA. With regards to sperm function, samples collected after 1 day of EA showed an increase in acrosome integrity, mitochondrial activity, and nuclear DNA integrity compared with samples collected after 4 days of EA. Epididymal function showed no difference between the two-time points. Although samples collected after 4 days of EA showed better results for sperm quantity, samples collected after 1 day of EA showed better qualitative results, including motility, oxidative activity, and sperm function. Thus, it can be concluded that sperm storage at the epididymal tail may make spermatozoa more susceptible to oxidative damage. LAY SUMMARY: According to the World Health Organization guidelines, stopping ejaculation for 2 to 7 days is recommended before sperm collection for semen analysis. However, the evidence that supports these recommendations is limited. Our study aimed to compare how sperm quality was affected in samples collected after stopping ejaculation for 1 day and 4 days (two samples per man) in a total of 65 men. Although sample collection after stopping ejaculation for 4 days showed better semen quantity (volume and sperm concentration), sample collection after stopping ejaculation for 1 day showed better sperm motility and function. If not ejaculated, sperm are stored in the epididymis tail located in the scrotum beside the testicles and our study suggests that longer sperm storage may damage sperm quality. The results from this study may be used to inform guidance for sperm collection for use in assisted reproduction techniques, and lead to an improvement in both fertilization and implantation rates.

Systemic arterial hypertension leads to decreased semen quality and alterations in the testicular microcirculation in rats.

Arterial hypertension is a cardiovascular disease that leads to important systemic alterations and drastically impairs normal organ function over time. Hypertension affects around 700 million men of reproductive age and hypertensive men present increased risk for reproductive disorders, such as erectile dysfunction. However, the link between arterial hypertension and male reproductive disorders is associative at best. Moreover, many studies have reported associations between decreased male fertility and/or semen quality and alterations to general male health. In this study we aim to investigate the effect of systemic high blood pressure in sperm quality, sperm functional characteristics and testicular physiology in a rat model. Hypertensive rats presented altered testicular morphology - mainly vascular alterations and impaired testicular vasomotion. Hypertensive rats also presented decrease in sperm concentration, DNA integrity and increased percentages of sperm with dysfunctional mitochondria, intracellular superoxide anion activity and abnormal morphology. This study provides mechanistic insights by which arterial hypertension affects the testes, evidencing the testes as another target organ for hypertension as well as its impact on sperm quality.

Carbamazepine-exposure during gestation and lactation affects pubertal onset and spermatic parameters in male pubertal offspring.

Carbamazepine (CBZ) is an anti-epileptic drug that acts on Leydig cells, affecting steroidogenesis and causes fetal malformation. The aim of this study was to investigate the effects of CBZ on male sexual maturation and other male parameters. Rat dams were treated with CBZ during pregnancy and breastfeeding. The anogenital distance (AGD) and the anogenital index (AGI) were obtained. Testicular descent and preputial separation were also evaluated. The offspring was euthanized at PND 41 and 63. The accessory glands were weighed and the testes were collected for histopathological, morphometric and sterological analyses. The numerical density of Leydig cells and hormone dosage were obtained. CBZ caused an increase of AGI and a delay of testicular descent and of preputial separation. CBZ also caused a decrease of testosterone level and of sperm count and an increase of abnormal sperm. These results indicate that CBZ delays puberty onset and affects steroidogenesis and sperm quality.