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.

Seasonal evaluations of urinary androgen metabolites and semen quality in domestic long-tailed chinchilla (Chinchilla lanigera) under natural photoperiod.

Chinchilla spp. is a South American hystricomorph rodent genus currently considered almost extinct in the wild. The high quality of chinchilla fur motivated the harvesting of chinchillas for the fur market. Reproductive biology advances come from studies on commercially exploited animals, especially Chinchilla lanigera. We studied seasonal variation of urinary androgen metabolites, sperm concentration and sperm functional activity in males of domestic Chinchilla lanigera under natural photoperiod. In Córdoba city (31° S-64° W; Argentina), within the same latitudes as those of the historic Andean distribution (tropical deserts; 15°-34° S), domestic males (n=7) were studied in May (autumn), August (winter), November (spring), and February (summer). Urine was seasonally collected (over 24h; once for season, 4 in total) to measure urinary androgen metabolites (RIA), before semen collection by electroejaculation. The results indicated that although testicular volume (relative to body weight) and values of sperm functional activity did not show seasonal changes, a seasonal variation in androgen excretion was detected, with the highest values occurring during "short" light/dark cycles (autumn-winter). In addition, viable spermatozoa with intact acrosome mean values during winter-spring were higher than in autumn or summer. This study provides information that might contribute to the assessment of testicular activity in male chinchilla subjected to genetic selection in the fur industry. In addition, since domestic chinchilla still share some genomic characteristics with their counterparts in the wild, results presented may alsocontribute to ex situ breeding program of endangered chinchilla. In conclusion, natural photoperiod cycle affects testicular activity in domestic chinchilla.

Reproduction in chinchilla (Chinchilla lanigera): current status of environmental control of gonadal activity and advances in reproductive techniques.

A review of the biology of reproduction of chinchilla, focusing on environmental control of the gonadal activity, is presented. Chinchilla is a South American hystricomorph rodent genus currently considered almost extinct in the wild. However, a domestic form is still widespread in breeding farms around the world. Information regarding their reproductive biology has been obtained from studies on captive animals. In the case of Chinchilla lanigera, a seasonal reproductive pattern has been frequently reported in breeding facilities, but factors that might trigger gonadal activity have not been identified. The available information on reproductive productivity in farms worldwide shows a range of 1.2 to 2.4 deliveries per female per yr (with up to 2.1 weaned young per female per yr). Indeed, as found in all rodents, chinchillas can multiply at high fecundity and fertility rates (4 to 6 follicles mature during estrous cycles). Some new research avenues are postulated to improve the control of gonadal activity by means of environmental and/or pharmacologic factors. Furthermore, reproductive techniques that have been validated in chinchilla are reviewed (noninvasive hormone monitoring, semen collection, sperm cryopreservation, estrus induction), and several technical steps are proposed to be able to achieve AI. Because domesticated chinchilla still share some genomic characteristics with their counterparts in the wild, validated reproductive techniques in chinchilla males and females might contribute to the success of breeding programs.

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.

Hippocampal effects of neuronostatin on memory, anxiety-like behavior and food intake in rats.

A 13-amino acid peptide named neuronostatin (NST) encoded in the somatostatin pro-hormone has been recently reported. It is produced throughout the body, particularly in brain areas that have significant actions over the metabolic and autonomic regulation. The present study was performed in order to elucidate the functional role of NST on memory, anxiety-like behavior and food intake and the hippocampal participation in these effects. When the peptide was intra-hippocampally administered at 3.0 nmol/µl, it impaired memory retention in both, object recognition and step-down test. Also, this dose blocked the hippocampal long-term potentiation (LTP) generation. When NST was intra-hippocampally administered at 0.3 nmol/µl and 3.0 nmol/µl, anxiolytic effects were observed. Also, the administration in the third ventricle at the higher dose (3.0 nmol/µl) induced similar effects, and both doses reduced food intake. The main result of the present study is the relevance of the hippocampal formation in the behavioral effects induced by NST, and these effects could be associated to a reduced hippocampal synaptic plasticity.

Seminal quality and neutral alpha-glucosidase activity after sequential electroejaculation of chinchilla (Ch. lanigera).

The objectives of this study of seminal quality of chinchilla (Chinchilla lanigera) males were to evaluate (1) the use of neutral alpha-glucosidase (NAG) as a functional epididymal marker in this species, and (2) the effects of repetitive electroejaculation on sperm function and seminal NAG concentration. Semen was obtained by electroejaculation from sexually mature domestic Ch. lanigera males (n=6) once a week for six consecutive weeks, and evaluated to assess seminal volume and NAG activity, and sperm concentration and functional activity (motility, viability, membrane and acrosome integrity). Body weight was determined in all animals before each electroejaculation procedure. NAG activity was detected in all semen samples obtained, reaching a concentration of 55.4±6.8µU/mL. No significant variations were observed throughout the experimental period in any of the semen quality parameters evaluated. A reduction (P=0.001) in body weight was detected from the third week of experimentation and by the end of the experiments the animals lost a 7.2±0.9% of body weight. Overall, results in the present study confirm that NAG activity is detectable in chinchilla seminal plasma and that repetitive electroejaculation is not deleterious, on a short-term basis, to the semen characteristics.

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.

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.

Decreased memory for novel object recognition in chronically food-restricted mice is reversed by acute ghrelin administration.

It has been demonstrated, in normal and aged rats and mice, that acute i.c.v. ghrelin (Ghr) administration increases memory retention. In order to evaluate if this treatment, restores memory retention in animals exhibiting impaired memory, in the present work we selected a chronic food restriction mouse model (since undernutrition prejudices higher nervous functions). We employed adult female mice with 28 days of 50% food restriction and evaluated: a) behavioral performance using novel object recognition test for memory, and plus maze for anxiety-like behavior, b) some morphometric parameters as body and hepatic weights and c) plasma Ghr levels. The animals with 50% food restriction showed an increase in plasma Ghr levels and a decrease in morphometric parameters and in the percentage of novel object recognition time. When the peptide was i.c.v. injected in food-restricted animals (0.03, 0.3 or 3.0 nmol/microl), memory increases in relation to food-restricted mice injected with vehicle, reaching a performance similar to controls.

Functional activity of frozen thawed Chinchilla lanigera spermatozoa cryopreserved with glycerol or ethylene glycol.

The cryopreservation of spermatozoa constitutes a valuable tool for the captive breeding management of valuable and/or threatened species. Chinchilla lanigera is a species almost extinct in the wild, and the domestic counterpart has one of the most valuable pelts in the world. The objectives of this study were to: (i) compare the functional activity of post-thawed chinchilla spermatozoa cryopreserved at -196 degrees C either with glycerol (G) or ethylene glycol (EG) as cryoprotectants (1 m final concentration) and (ii) investigate the effects of incubating the gametes for 4 h in the presence or in the absence of the cryoprotectants; evaluations were performed taking into account motility, viability, response to hypo-osmotic shock and acrosome integrity of the cells. Parameters reflecting post-thaw (0 h) sperm functional activity were significantly lower than those of freshly ejaculated gametes. When comparing the cryoprotectant efficiency of G vs EG, neither cryoprotectant agent offered appreciable advantages. After 4 h of incubation, in the presence or absence of the cryoprotectant agent, a rapid and significant decrease was found in all functional parameters and remained at approximately 20-30% motile, viable and viable acrosome intact cells. Viability was significantly lower when the cryoprotectant was removed from the media (possibly due to the centrifugation process). With respect to the maintenance of sperm membrane integrity, only approximately 10% of cells showed membrane resistance to hypo-osmotic conditions after the 4 h incubation period. These results constitute new insights for cryopreservation protocols and the development of assisted reproductive techniques in this species.

Electroejaculation in the Chinchilla (Chinchilla lanigera): effects of anesthesia on seminal characteristics.

Repetitive electroejaculation is probably extremely stressful in conscious animals and could adversely affect fertility. The present study was designed to (a) evaluate the effects of anesthesia (40 mg ketamine/kg body weight, i.m.) on a method of electroejaculation used previously in conscious chinchillas (Chinchilla lanigera), and (b) determine the quality of the electroejaculated semen obtained under anesthesia. In Experiment 1 (8 animals), a 4 x 4 Latin square design was used to study the effects of anesthesia and ejaculatory voltage on semen collection, ejaculate volume, sperm concentration, motility, viability, response to the hypoosmotic swelling test (HOST), and acrosomal status. In Experiment 2 (12 animals), the effects of differing voltages and the number of stimuli on ejaculation by conscious or anesthetized males was determined. In both experiments, all the conscious animals ejaculated, but only 60% ejaculated under anesthesia and they required more stimuli and higher voltages to achieve ejaculation. Ejaculate volume was significantly lower in anesthetized (<5 microl) than in conscious animals (>40 microl), but sperm concentration was unaffected. None of the indices of sperm quality were affected by anesthesia. The techniques we have developed in anesthetized domestic chinchillas should be applicable to endangered chinchillas in the wild, and though the number of sperm available is reduced, there are still sufficient for assisted reproduction.

Relación entre calidad seminal y consumo de alcohol y tabaco / Relation between seminal quality and smoking and alcohol consumption

Existen indicios que sugieren una declinación en la calidad del semen humano en las últimas décadas. Se ha involucrado como responsables entre otros, hábitos tóxicos como consumo de alcohol y/o tabaco, relevantes por su amplia difusión en nuestro medio. En el presente trabajo investigamos retrospectivamente posibles correlaciones entre estos factores y alteraciones en el espermograma convencional (según normas de la OMS y morfología según criterio estricto de Kruger), en pacientes de Córdoba (Argentina), pertenecientes a parejas con esterilidad diagnosticada o bajo estudio que respondieron a una encuesta tipo desde 1990 a 1999 (n=8278). Excluidos los casos de varicocele, infecciones genitourinarias, parotiditis, azoospermia y/o criptorquidia, se procesaron los datos de 3976 espermogramas. El 80.3 por ciento informó ningún hábito tóxico, el 9.3 por ciento consumía tabaco, el 5.9 por ciento alcohol y el 4.3 por ciento ambos. Existe una concordancia significativa entre ambos tipos de hábitos (Kappa 0.28, p<0.05). En semen de pacientes abstemios no fumadores (n=3194) se determinó: volumen: 3.0 ñ 0.0 ml; concentración: 50.9 ñ 0.9 x 10 6/ml; espermatozoides móviles: 44.0 ñ 0.4 por ciento; rápidos: 31.6 ñ 0.3; inmóviles vivos: 36.0 ñ 0.2. En semen de pacientes que informaron ambos tipos de hábitos (n=174), los mismos parámetros registraron los siguientes valores: 2.7 ñ 0.1 ml; 45.3 ñ 3.69 x 10 6/ml; 39.6 ñ 1.6 por ciento; 27.2 ñ 1.1 por ciento y 39.9 ñ 1.0 por ciento respectivamente (p<0.05 vs el grupo anterior en todos los parámetros). El descenso simultáneo de volumen y concentración permite inferir que la cantidad total de gametas eyacuadas también se redujo. Cuando los datos se agrupan por bienios, se evidenció la tendencia al incremento temporal en los casos de consumo de alcohol y/o tabaco, y detectamos deterioro concomitante en la calidad seminal. Los hallazgos descriptos, apoyan la hipótesis de que las causas de deterioro seminal son generalmente multifactoriales; dosis incorporada y tiempo de administración son factores adicionales a tener en cuenta

Relación entre calidad seminal y consumo de alcohol y tabaco / Relation between seminal quality and smoking and alcohol consumption

Existen indicios que sugieren una declinación en la calidad del semen humano en las últimas décadas. Se ha involucrado como responsables entre otros, hábitos tóxicos como consumo de alcohol y/o tabaco, relevantes por su amplia difusión en nuestro medio. En el presente trabajo investigamos retrospectivamente posibles correlaciones entre estos factores y alteraciones en el espermograma convencional (según normas de la OMS y morfología según criterio estricto de Kruger), en pacientes de Córdoba (Argentina), pertenecientes a parejas con esterilidad diagnosticada o bajo estudio que respondieron a una encuesta tipo desde 1990 a 1999 (n=8278). Excluidos los casos de varicocele, infecciones genitourinarias, parotiditis, azoospermia y/o criptorquidia, se procesaron los datos de 3976 espermogramas. El 80.3 por ciento informó ningún hábito tóxico, el 9.3 por ciento consumía tabaco, el 5.9 por ciento alcohol y el 4.3 por ciento ambos. Existe una concordancia significativa entre ambos tipos de hábitos (Kappa 0.28, p<0.05). En semen de pacientes abstemios no fumadores (n=3194) se determinó: volumen: 3.0 ñ 0.0 ml; concentración: 50.9 ñ 0.9 x 10 6/ml; espermatozoides móviles: 44.0 ñ 0.4 por ciento; rápidos: 31.6 ñ 0.3; inmóviles vivos: 36.0 ñ 0.2. En semen de pacientes que informaron ambos tipos de hábitos (n=174), los mismos parámetros registraron los siguientes valores: 2.7 ñ 0.1 ml; 45.3 ñ 3.69 x 10 6/ml; 39.6 ñ 1.6 por ciento; 27.2 ñ 1.1 por ciento y 39.9 ñ 1.0 por ciento respectivamente (p<0.05 vs el grupo anterior en todos los parámetros). El descenso simultáneo de volumen y concentración permite inferir que la cantidad total de gametas eyacuadas también se redujo. Cuando los datos se agrupan por bienios, se evidenció la tendencia al incremento temporal en los casos de consumo de alcohol y/o tabaco, y detectamos deterioro concomitante en la calidad seminal. Los hallazgos descriptos, apoyan la hipótesis de que las causas de deterioro seminal son generalmente multifactoriales; dosis incorporada y tiempo de administración son factores adicionales a tener en cuenta (AU)

In vitro parthenogenesis of mouse oocytes under several experimental conditions.

Although the in vitro fertilisation index is a parameter commonly employed to investigate sperm functional activity, little attention has been given to the occurrence of parthenogenesis. The purpose of this study was to study at 6 h or 22 h incubation: (a) the cleavage-related events that occur in in vitro incubated mouse oocytes, in the absence (parthenogenesis) or presence of homologous spermatozoa; (b) the effect of mineral oil, commonly used in in vitro fertilisation assays; (c) the effect of piroxicam, a prostaglandin synthesis inhibitor, on the parthenogenetic rate; and (d) the influence on parthenogenesis of spontaneous loss of the cumulus oophorus coat during incubation. Under the experimental conditions employed, there was parthenogenetic activation and activation due to fertilisation. Both increased in a time-dependent manner. The mineral oil enhanced the parthenogenetic rate at 22 h incubation. However, it did not have any effect when the oocytes were inseminated. Since we can not discriminate how much of this activation was due to fertilisation and how much to parthenogenesis we must be very careful with this comparison. Piroxicam 10(-8) M did not show any effect on the mouse oocyte parthenogenetic rate at neither 6 h or 22 h incubation. Our results suggest that oocyte susceptibility to spontaneous parthenogenetic activation may be modified by the presence of the cumulus and corona radiata cells. In conclusion, we consider that further rigorous studies on these influences are necessary in order to confer more reliability on the results.

Functional activity of mouse sperm was not affected by low doses of aspirin-like drugs.

To investigate some possible effects of low doses of nonsteroidal anti-inflammatory drugs upon functional activity of mouse sperm, the authors injected lysine acetyl salicylate (im 14.3 mg/kg day(-1), ibuprofen (ip 5.6 mg/kg day(-1)), or piroxicam (ip 0.28 mg/kg day(-1) to pregnant females (the male cohort was sacrificed at adulthood) (A) or to adult males during 35 (B) or 60 (C) days. Parameters measured were motility, viability, acrosomal integrity, responses to hypoosmotic shock, in vitro fertilization index, and testosterone plasma levels. Salicylate evoked a slight reduction in the percentage of swollen gametes in A, and ibuprofen diminished testosterone plasma levels in B. The other parameters remained unchanged in all groups. Results are well supported by the low doses assayed, which are equivalent to the content of one tablet commercially available for each compound.

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 Tyrode's 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.

Functional activity of epididymal Chinchilla laniger spermatozoa cryopreserved in different extenders.

Chinchilla laniger is an endangered species and improved cryopreservation of spermatozoa would constitute a significant advance in the development of assisted reproductive techniques in this species. The functional activity of epididymal spermatozoa from adult males was studied immediately after extrusion and after 24 hours incubation, and the ability of five extenders to protect these gametes during cryopreservation was determined. A decrease in sperm motility, viability, acrosome intact cells and response to hypo-osmotic swelling test was detected 24 hours later. The extenders here assayed showed well-defined differences in their cryoprotective ability; however such differences could not be attributed to any one of their individual components. The presence of TES plus Tris, the proportion of the individual constituents and/or the differences in metabolic substrate content could explain the above-mentioned finding. The results indicate that cryo-buffer II (TES-Tris-egg yolk-fructose-glycerol) is the most powerful protector of sperm functional activity in this species.

Activity of Chinchilla laniger spermatozoa collected by electroejaculation and cryopreserved.

Because reproductive studies and the application of assisted reproductive techniques are relevant issues for an endangered species such as Chinchila laniger, the availability of a source of viable spermatozoa becomes of utmost importance. In this paper, we evaluate several functional parameters (motility, viability, response to hypoosmotic swelling test and acrosomal integrity) of fresh or frozen-thawed spermatozoa. Electro-ejaculation trials (50-cyc/sec sinusoidal wave was applied for 5 of every 10 sec) were successful in all unanesthetized animals. After volume (108.3 +/- 12.0 microL, n = 15) and concentration (421.8 +/- 34.4 x 10(6) cells/mL, n = 15) measurements, the above mentioned parameters were determined. In frozen-thawed semen samples sperm motility, viability, hypoosmotic swelling test and acrosomal integrity were significantly lower than in fresh semen samples. The results clearly indicated that electro-ejaculation is a useful method for evaluating spermatozoa for genetic analysis or for used in Al in this species. In addition, the cryopreservation procedure in this study preserved adequate levels of functional sperm activity.

Differential effects of pharmacologically generated reactive oxygen species upon functional activity of epididymal mouse spermatozoa.

Several studies indicate that reactive oxygen species (ROS) are involved in defective sperm function pathophysiology. In this study we attempted to determine differentially the effects of xanthine (0.12 mM) plus xanthine oxidase (0.035 U/mL) (X+XO, a ROS promoter system), ROS scavengers (Tiron (TIR, 15 mM); catalase (CAT, 10 micrograms/mL); dimethylsulfoxide (DMSO, 140 mM)), and X+XO plus scavengers on several epididymal mouse spermatozoa functional parameters, incubated in NTPC medium, for 29 min. In the presence of X+XO, progressive gametes significantly diminished. TIR or CAT attenuated this effect, but DMSO did not. Inversely, X+XO increased the bending-forms population; only TIR reversed this phenomenon. The ROS promoter system diminished the viable cell population; all scavengers assayed maintained sperm viability at levels similar to control ones. When exposed to hypoosmotic shock after 29 min incubation with X+XO, the percentage of swollen cells decreased; TIR, CAT, or DMSO did not prevent this effect. Our experiments demonstrate that it is possible to differentiate the deleterious ROS effects upon sperm functional activity. O-2. and H2O2 preferentially seem to modify sperm motility, O-2. exhibiting the greatest ability for generating bending-form gametes, OH-being the most lethal ROS. In addition, sperm membrane clearly appears as the most damaged structure.

Changes in corticosterone levels and sperm functional activity by chronic stress in rats.

Corticosterone levels and epididymal sperm functional activity have been studied in rats subjected to immobilization stress (A: 12 days) or variable chronic stress (B: 24 days; C: 32 days and D: 32 days plus 28 days without stress). Plasma corticosterone levels were significantly enhanced in B and C groups. Body and testicular weight significantly decreased in C and D groups. A decrease in viability or percentage of progressive epididymal spermatozoa was detected in C and D groups. Responses of spermatozoa to hypoosmotic shock remained unaltered in all groups. Results suggest that sustained increase in activity of the hypothalamo-adenohypophyseal-adrenal cortical system alters the activity of the hypothalamo-adenohypophyseal-testicular axis.