L. M. Vincenti

The Effect of Alcohol, Tobacco, and Aspirin Consumption on Seminal Quality among Healthy Young Men

Abstract In this study, the authors examined the effects of alcohol, tobacco, and drug use on plasma testosterone and seminal parameters (in accordance with the World Health Organizations standards) in healthy Argentine medical students (n = 34). Some alterations in seminal parameters were detected in 19 (56%) subjects. Alcohol and tobacco use were correlated significantly, p = 0.005; subjects who used these substances exhibited a nonsignificant reduction in sperm concentration, motility, viability, and normal morphology. There was a significant decrease in sperm motility among students who used moderate amounts of aspirin (i.e., ≥ 500 mg/wk). The authors concluded that alcohol, tobacco, and aspirin use could have had detrimental effects on seminal parameters and that men who wish to procreate should be warned of such effects. Doses, exposure time, and interactions with other variables deserve additional study.

Inhibitory effects of ghrelin on sexual behavior: role of the peptide in the receptivity reduction induced by food restriction in mice.

Ghrelin (Ghr) is a gut/hypothalamus peptide with inhibitory actions on reproductive physiology; however, there are no previous reports of its role on estrous behavior. Under the hypothesis that the increase of plasma Ghr during food restriction (FR) is responsible for receptivity reduction, we intended to evaluate the receptivity percentage of female mice subjected to: exp. 1) acute and chronic FR and Ghr administration (3 nmol/animal/day, s. c.) and exp. 2) the co-administration of a ghrelin antagonist [ant=(d-Lys3)-GHRP-6; 6 nmol/animal/day s. c.]. All females were ovariectomized, primed with steroids, trained, and randomly subjected every week to each one of several protocols, followed by a behavioral test. Experiment 1 (n=8): basal, no treatment; acute FR (aFR), 24-h fasting; chronic FR (cFR), 50% FR for 5 days; acute ghrelin (aGhr), Ghr 30 min before test and chronic ghrelin (cGhr), Ghr for 5 days. Except for cGhr, all treatments significantly decreased the percentage of receptivity (mean±SEM): basal 61.9±6.0, aFR 33.1±8.1, cFR 18.8±7.7, aGhr 45.6±10.6, p<0.05 vs. basal. In exp. 2 (n=11), except for cFR+ant (55.0±6.4) the co-administration of the antagonist reversed the deleterious effects detected in exp. 1: basal 70.9±5.4; aFR+ant 72.3±7.6; aGhr+ant 73.6±4.7. As expected, the administration of vehicle or antagonist alone did not modify receptivity. Besides, we found a significant correlation between percentage of body weight loss and percentage of receptivity reduction (r=0.62, p=0.0004). This is the first study demonstrating that ghrelin is able to inhibit female mice sexual behavior and that is involved, at least in part, in receptivity reduction after food scarcity.

INFLUENCE OF PENTOXIFYLLINE ON SPERM MEMBRANE FUNCTIONAL INTEGRITY

In epididymal mouse spermatozoa, the effects of dibutyryl cyclic adenosine monophosphate 1 mmol/L (dbcAMP), pentoxifylline 5 mmol/L (PX), and/or mastoparan 50 mumol/L (MT) were evaluated for the following parameters: percentage of motile cells and response to hypoosmotic shock (HOS). The gametes were incubated during 80 min (A) or 200 min (B) in Tyrodes medium, and the drugs were added during the last 20 min. In A, dbcAMP + PX (61.5 +/- 5.4%; n = 10) enhanced and MT decreased significantly the population of motile cells (13.4 +/- 5.4%; n = 6) (control: 47.6 +/- 3.9%; n = 11). In B, PX significantly increased this parameter and MT plus PX also exerted a significant detrimental effect. Responses to HOS dropped significantly in the presence of PX + MT in A or in B; in this latter condition a similar decrease was evoked by MT alone. A positive correlation between percentages of swollen and motile spermatozoa was detected in A or in B in samples incubated with PX (r = .58, n = 11 and r = .76, n = 10; p < .05, respectively). These results that support that, in mouse sperm tail, PX would preserve functional membrane integrity, a relevant condition for adequate motility.

Neutral α-glucosidase activity in mouse: a marker of epididymal function?

Neutral alpha-glucosidase (NAG) activity is considered a functional epididymal marker in several species. Unlike the rat, no NAG activity has been detected in mice. The aims of the present study were to evaluate NAG secretory activity (the supernatant of the incubated tissue) in mouse epididymis and to determine whether it could be used as a functional epididymal marker. Epididymides (whole or in parts) were incubated in the presence or absence of testosterone (10(-5) m) and secretory NAG activity was compared with known positive controls. Furthermore, we compared enzyme activity in epididymides from well-fed and undernourished mice (50% food restriction for 21 days), a model that alters the epididymal maturation processes. Spectrophotometric analysis revealed NAG activity in mouse epididymis (22.6 +/- 3.7 mU g(-1) tissue; n = 4), being higher in the caput. NAG activity was statistically higher in the caput than in the corpus and in the cauda. No significant differences existed between the caput NAG activity and complete epididymis NAG activity. In undernourished mice, we confirmed changes in epididymal maturation observed previously (i.e. increased number of immature spermatozoa and diminution of the sperm concentration). Concordantly, the epididymides of undernourished mice exhibited decreased enzyme secretory activity, which increased to values similar to those seen in controls following incubation in the presence of testosterone (22.5 +/- 2.6, 12.5 +/- 1.0 and 22.4 +/- 3.7 mU g(-1) tissue, n = 9 in control (n = 7), undernourished (n = 9) and undernourished + testosterone groups (n = 9), respectively). In conclusion, NAG activity was detected in mouse epididymis. Although the present study supports the possibility of using NAG as an epididymal marker, more studies are necessary to effectively prove that NAG activity can be used as an epididymal marker.

Effects of hexarelin (a ghrelin analogue) on fertilisation and the pre- and postnatal development of mice

Ghrelin (Ghr) has been associated with reproductive physiology and pre- and postnatal development. The objectives of the present study were to evaluate the effects of hexarelin (HEX; 100 or 200 microg kg(-1) day(-1)), a therapeutic Ghr analogue, on: (1) embryo development 60 h post ovulation, induced pharmacologically, in pregnant mice; (2) the physical, neurobiological and sexual development of offspring of female mice injected with HEX during the first, second or third week of pregnancy or throughout the entire pregnancy; and (3) adult memory acquisition in these offspring. We also evaluated the effects of chronic HEX administration on memory acquisition in adult mice. Treatment of non-pregnant female mice with HEX decreased ovulation rate. However, treatment of pregnant mice with HEX at any time during pregnancy tended to accelerate offspring maturation, regardless of bodyweight. This effect was only significant on neurobiological parameters following treatment during the first week. HEX treatment during the first week and/or throughout the entire pregnancy resulted in impaired memory acquisition in the offspring, with female mice being more susceptible to these effects. Similar results were observed for the effects of chronic HEX treatment on memory acquisition in adult mice. In conclusion, HEX seems to exert differential effects depending on when it is administered. Because HEX has started to be used therapeutically, its deleterious effects on ovulation and memory acquisition must be further evaluated.

Reproductive performance and fertility in male and female adult mice chronically treated with hexarelin

Hexarelin (HEXr), a synthetic ghrelin analogue, has been associated with modifications of reproductive physiology. In previous studies of adult mice, we detected that HEXr induced significantly reduced ovulation rate and significant correlation coefficients between sexual maturation and corporal weight in offspring. In this study, we investigated the effects of chronic HEXr administration on sperm concentration and functional activity, oestrous cyclicity and pregnancy index, in addition to the number of fetuses and its correlation with the number of corpora lutea. Adult Albino swiss mice were injected (sc) daily with HEXr: 100 μgkg(-1) day(-1) (HEXr D1) or 200 μgkg(-1) day(-1) (HEXr D2) for 53 days in males and 30 days in females. We detected a significantly decreased ratio in the number of fetuses per corpora lutea in females treated with HEXr D2 for 30 days before mating and during the first 6 days of pregnancy, in addition to a downward trend in the pregnancy index and percentage of females impregnated by each male treated with both doses of the analogue. Although we did not find any significant effect on additional parameters evaluated in both genders, we propose certain effects of HEXr on the implantation process and/or early development of embryos and over the in vivo reproductive capability of males.

Mouse plasma progesterone levels are affected by different dietary ω6/ω3 ratios.

An imbalance in the dietary polyunsaturated fatty acids (PUFAs) ω6/ω3 ratio, could influence negatively the reproductive performance. The aim of the study was to assess the effects of chronic administration of diets enriched with soybean or sunflower oils with different ω6/ω3 ratios on the reproductive parameters of adult female mice. Mice were fed different diets for 90 days: a commercial diet (CD), a 5 or 10% soy oil-enriched diet (SOD5 and SOD10, respectively), and a 5 or 10% sunflower oil-enriched diet (SFOD5 and SFOD10, respectively). The parameters evaluated were: body weight and food intake, estrous cycle, plasma progesterone concentration, ovulation rate, and oocyte quality. Progesterone concentrations (ng/ml) were significantly higher in the SFOD10: 14.9±2.8 vs CD: 5.4±1.2; SOD5: 5.6±1.1 and SFOD5: 4.6±1.4. Additional parameters evaluated were not affected. However, metestrous and luteal phases were shorter in subjects receiving SOD and longer in those under SFOD diets. In SFOD, there was a trend towards a smaller number of recruited oocytes compared to CD and SOD and a higher percentage of cleaved oocytes were quantified in SOD diets. A 3-month supply of a diet with elevated LA ω6/ALA ω3 ratio to adult female mice affects their reproductive physiology, modifying progesterone production, ovulation rate, and/or oocyte quality. Although some differences in the response to diets have been observed in several mammalian species, the present findings must be taken into consideration when a diet for optimizing reproductive capability is indicated.

Selection of a high quality subpopulation of frozen thawed bovine spermatozoa by filtration in a Sephadex column. An assessment of functional effects of progesterone

Summary It is accepted that cryopreservation exerts deleterious effects on functional characteristics of mammalian spermatozoa. Conventional procedures for processing frozen-thawed gametes, such as centrifugation, produce additional damage. In the present work, we investigated the efficacy of processing bovine cryopreserved semen by filtration in a Sephadex column (SF group) or by washing by centrifugation (100 g, 10 min, twice) (W group); the results obtained from both procedures were compared to untreated samples (C group). The effects of in vitro addition of progesterone (10 μM, 20 min) upon sperm functional activity were studied also. The evaluated sperm parameters were concentration, motility (progressive or non progressive cells), viability and acrosome reaction. They were measured at time 0 (immediately after processing) or after 4 h incubation in capacitating conditions. Sperm concentration was (× 10−6): 37.5 ± 5.4 in C, 8.3 ± 2.1 in W and 12.5 ± 2.9 in SF. The percentages of motile, progressive, viable or acrosome intact gametes were significantly higher in SF than in W or in C. in SF group, after 4 h incubation in capacitating conditions, progesterone increased significantly the population of acrosome reacted cells whereas this parameter was not modified when the cells were incubated in absence of heparin. Motility and viability were not modified by the hormone. We conclude that Sephadex filtration method is an adequate tool to obtain a subpopulation of spermatozoa with superior quality, as assessed by motility, viability and acrosomal integrity; besides, our results strongly support that, as in other species, progesterone would be a physiological inductor of acrosome reaction in bovine.

Body mass index and human sperm quality: neither one extreme nor the other

The aim of the present study was to investigate the still contentious association between body mass index (BMI) and seminal quality. To this end, 4860 male patients (aged 18-65 years; non-smokers and non-drinkers), were classified according to BMI as either underweight (UW; BMI <20kgm-2; n=45), normal weight (NW; BMI 20-24.9kgm-2; n=1330), overweight (OW; BMI 25-29.9kgm-2; n=2493), obese (OB; BMI 30-39.9kgm-2; n=926) or morbidly obese (MOB; BMI ≥40kgm-2; n=57). Conventional semen parameters and seminal concentrations of fructose, citric acid and neutral α-glucosidase (NAG) were evaluated. The four parameters that reflect epididymal maturation were significantly lower in the UW and MOB groups compared with NW, OW and OB groups: sperm concentration, total sperm count (103.3±11.4 and 121.5±20.6 and vs 157.9±3.6, 152.4±2.7 or 142.1±4.3 spermatozoa ejaculate-1 respectively, P<0.05), motility (41.8±2.5 and 42.6±2.6 vs 47.8±0.5, 48.0±0.4 or 46.3±0.6 % of motile spermatozoa respectively, P<0.05) and NAG (45.2±6.6 and 60.1±7.9 vs 71.5±1.9, 64.7±1.3 or 63.1±2.1 mU ejaculate-1 respectively, P<0.05). Moreover, the percentage of morphologically normal spermatozoa was decreased in the MOB group compared with the UW, NW, OW and OB groups (4.8±0.6% vs 6.0±0.8%, 6.9±0.1%, 6.8±0.1 and 6.4±0.2%, respectively; P<0.05). In addition, men in the MOB group had an increased risk (2.3- to 4.9-fold greater) of suffering oligospermia and teratospermia (P<0.05). Both morbid obesity and being underweight have a negative effect on sperm quality, particularly epididymal maturation. These results show the importance of an adequate or normal bodyweight as the natural best option for fertility, with both extremes of the BMI scale as negative prognostic factors.

Maternal and postnatal high-fat diets with high ω6 : ω3 ratios affect the reproductive performance of male offspring in the mouse

High-fat diets (HFDs) are an acknowledged risk factor for male subfertility, but the underlying mechanisms remain unclear. In the present study we compared the effects of two HFDs with different ω6:ω3 ratios, one enriched with soy oil (SOD; ω6:ω3=9.62) and another enriched with sunflower oil (SFOD; ω6:ω3=51.55), with those of a commercial diet (CD; ω6:ω3=19.87), supplied from pregnancy to adulthood, on morphometric parameters and reproductive performance in adult male mice (recommended ω6:ω3 for rodents=1-6). Bodyweight was significantly higher in the SFOD than CD group, and relative testicular weight was significantly lower in the SFOD than the other two groups. SFOD altered sperm performance: it reduced sperm viability (mean±s.e.m.; 76.00±1.35% vs 82.50±1.45% and 80.63±1.00% in the SFOD vs CD and SOD groups respectively; P<0.05) and increased the percentage of immature spermatozoa (71.88±7.17% vs 51.38±5.87% and 48.00±5.72% in the SFOD vs CD and SOD groups respectively; P<0.05). The epididymal ω6:ω3 ratio was higher in the SFOD versus CD and SOD groups, whereas the unsaturation index was higher in the SOD and SFOD groups than in CD group. Sperm membrane integrity was diminished in both the SOD and SFOD groups, but there was no difference in sperm reactive oxygen species production in these two groups compared with the CD group. The fertilisation rate was lower in the SFOD compared with the CD and SOD groups. In conclusion, although both HFDs affected sperm quality, the fertilising ability was more altered by the excessive dietary ω6:ω3 ratio than by the net ω6 content.