Role of ghrelin in fertilization, early embryo development, and implantation periods.

In order to clarify the physiological role of ghrelin in gestation, we evaluated the effects of administration of exogenous ghrelin (2 or 4 nmol/animal per day) or its antagonist (6 nmol/animal per day of (d-Lys3)GHRP6) on fertilization, early embryo development, and implantation periods in mice. Three experiments were performed, treating female mice with ghrelin or its antagonist: i) starting from 1 week before copulation to 12 h after copulation, mice were killed at day 18 of gestation; ii) since ovulation induction until 80 h later, when we retrieved the embryos from oviducts/uterus, and iii) starting from days 3 to 7 of gestation (peri-implantation), mice were killed at day 18. In experiments 1 and 3, the antagonist and/or the highest dose of ghrelin significantly increased the percentage of atrophied fetuses and that of females exhibiting this finding or a higher amount of corpora lutea compared with fetuses (nCL/nF) (experiment 3: higher nCL/nF-atrophied fetuses: ghrelin 4, 71.4-71.4% and antagonist, 75.0-62.5% vs ghrelin 2, 46.2-15.4% and control, 10-0.0%; n=7-13 females/group; P<0.01). In experiment 2, the antagonist diminished the fertilization rate, and both, ghrelin and the antagonist, delayed embryo development (blastocysts: ghrelin 2, 62.5%; ghrelin 4, 50.6%; and antagonist, 61.0% vs control 78.4%; n=82-102 embryos/treatment; P<0.0001). In experiment 3, additionally, ghrelin (4 nmol/day) and the antagonist significantly diminished the weight gain of fetuses and dams during pregnancy. Our results indicate that not only hyperghrelinemia but also the inhibition of the endogenous ghrelin effects exerts negative effects on the fertilization, implantation, and embryo/fetal development periods, supporting the hypothesis that ghrelin (in 'adequate' concentrations) has a physiological role in early gestational events.

The impact of obesity on male reproduction: its biological significance.

Since obesity and male subfertility have increased in parallel during the last decades, the hypothesis of an association between these two phenomena has been explored by several researchers. Although there is no consensus apparently obesity impacts men's reproductive potential by several mechanisms, like alterations on the hypothalamus-pituitary-testicular axis, modifications of spermatogenesis and semen quality and/or impairment of men's sexual health. This review intends to summarize the underlying bases of such alterations and propose new ones, without miscalculating their biological significance. Obesity is not rigorously related to subfertility; in addition, the existence of a genetic predisposition to obesity-linked sterility is currently under investigation. Nonetheless, the impact of obesity on male reproductive potential must be fully elucidated since the prevalence of obesity is increasing and consequently, the number of obese men with reduced fertility will also rise.

Semen quality and aging: analysis of 9.168 samples in Cordoba. Argentina.

OBJECTIVES: Concomitantly with the actual trend towards later fathering, more detailed studies are necessary to establish the relationship between male age and seminal features. The objective of the present paper was to evaluate the relationship of men age with semen quality and with the seminal levels of epididymal and accessory gland markers. METHODS: The study was conducted as a retrospective study of 9168 cases obtained from the Andrology and Reproduction Laboratory in Cordoba, Argentina for 10 years (1995-2004) (men ages 20 to 77). An important number of factors such as abstinence time, toxic habits, work conditions and drugs consumption has been statistically considered. The parameters measured were: seminal volume, sperm concentration, total sperm count, sperm motility, morphology and viability. Seminal levels of alpha-glucosidase, fructose and citric acid were also evaluated. RESULTS: We detected a significant decrease in seminal volume, sperm count, motility, viability and normal morphology, and a reduction in alpha-glucosidase and fructose levels in relation to age. CONCLUSIONS: Since semen quality is a tool for fertility prognosis estimation, the weight of evidence indicates that men may become progressively less fertile as they get older. Couples who decide to delay childbearing should be warned about this matter.

Envejecimiento y calidad seminal: un análisis en 9.168 casos en Córdoba. Argentina / Semen quality and aging: a 9.168 sample study in Cordoba. Argentina

OBJETIVO: En coincidencia con la actual tendencia hacia la paternidad tardía, son necesarios más estudios para establecer la relación entre la edad del varón y las características seminales.El objetivo del presente trabajo fue evaluar la relación de la edad con la calidad espermática y con los niveles seminales de marcadores funcionales del epidídimo y de glándulas anexas.MÉTODOS: este estudio retrospectivo fue realizado sobre 9168 casos obtenidos de hombres miembros de parejas con problemas de fertilidad que se presentaron en el Laboratorio de Andrología y Reproducción, en Córdoba, Argentina durante 10 años (1995-2004) (en pacientes entre 20 y 77 años). Se controló estadísticamente un importante número de posibles factores de confusión tales como tiempo de abstinencia sexual, hábitos tóxicos, condiciones laborales y consumo de medicamentos. Los parámetros evaluados fueron: volumen seminal, concentración espermática, número total de espermatozoides, motilidad, morfología y vitalidad espermática. Se cuantificaron además las concentraciones seminales de alfa-glucosidasa, fructosa y ácido cítrico.RESULTADOS: en el presente estudio detectamos un descenso significativo en el volumen seminal, el recuento espermático, la motilidad, la vitalidad y el porcentaje de espermatozoides morfológicamente normales, así como una reducción en los niveles de alfa-glucosidasa y fructosa seminales en relación con la edad.CONCLUSIONES: dado que la calidad seminal constituye un factor de pronóstico para la fertilidad masculina, las evidencias indican que los hombres podrían disminuir su fertilidad a medida que envejecen. Aquellas parejas que decidan postergar su paternidad deben ser advertidas acerca de este hecho(AU)

OBJECTIVES: Concomitantly with the actual trend towards later fathering, more detailed studies are necessary to establish the relationship between male age and seminal features.The objective of the present paper was to evaluate the relationship of men age with semen quality and with the seminal levels of epididymal and accessory gland markers.METHODS: The study was conducted as a retrospective study of 9168 cases obtained from the Andrology and Reproduction Laboratory in Cordoba, Argentina for 10 years (1995-2004) (men ages 20 to 77). An important number of factors such as abstinence time, toxic habits, work conditions and drugs consumption has been statistically considered. The parameters measured were: seminal volume, sperm concentration, total sperm count, sperm motility, morphology and viability. Seminal levels of alpha-glucosidase, fructose and citric acid were also evaluated.RESULTS: We detected a significant decrease in seminal volume, sperm count, motility, viability and normal morphology, and a reduction in alpha-glucosidase and fructose levels in relation to age.CONCLUSIONS: Since semen quality is a tool for fertility prognosis estimation, the weight of evidence indicates that men may become progressively less fertile as they get older. Couples who decide to delay childbearing should be warned about this matter(AU)

Year-round testicular volume and semen quality evaluations in captive Chinchilla lanigera.

In mammals, reproductive performance is usually associated with seasons. Chinchilla lanigera, an endemic South American rodent, reproduces throughout the year in captivity but its seasonal breeding pattern is not fully understood. The present study was designed to evaluate (bi-weekly) over 1 year: (1) testicular volume variations and (2) seminal volume, sperm concentration and functional activity changes. Five animals were studied; they were individually housed indoors (22.2 +/- 1.0 degrees C) under natural photoperiod in Argentina (Córdoba, 31 degrees S-64 degrees W). Semen was obtained by electroejaculation; a total of 116 ejaculates was evaluated. Monthly values for paired testicular volume were less in the middle of the summer than in other seasons (p < 0.006), while those for seminal volume and total spermatozoa/ejaculate were not significantly different; these variables ranged between 7.2-30.9 cm(3), 10-130 microL and 0.9-432.6 x 10(6), respectively. Spermatozoa concentration was (x 10(6)/mL) 2145.9 +/- 365.3 and the pH of semen was 7.3 +/- 0.0. Spermatozoa functional activity showed no significant differences between monthly evaluations; confidence intervals were calculated for the means of: motility, 92.2-95.8%; viability, 92.2-96.1%; swollen cells (hypo-osmotic swelling test), 81.2-87.7% and viable intact acrosome, 83.5-89.0%. The present study represents the first longitudinal reproductive assessment in the chinchilla male. In conclusion, males produce spermatozoa continuously that exhibit high quality functional activity.

Assessment of urine and fecal testosterone metabolite excretion in Chinchilla lanigera males.

Endemic chinchilla (Chinchilla spp.) populations are nearly extinct in the wild (South America). In captive animals (Chinchilla lanigera and C. brevicaudata), reproduction is characterized by poor fertility and limited by seasonal breeding patterns. Techniques applied for studying male reproductive physiology in these species are often invasive and stressful (i.e. repeated blood sampling for sexual steroids analysis). To evaluate endocrine testicular function, the present experiments were designed to (a) determine the main route of testosterone excretion (14C-testosterone infusion in four males); (b) validate urine and fecal testosterone metabolite measurements (HPLC was used to separate metabolites and immunoreactivity was assessed in all metabolites using a commercial testosterone radioimmunoassay, and parallelism, accuracy and precision tests were conducted to validate the immunoassay); and (c) investigate the biological relevance of the techniques applied (quantification of testosterone metabolite excretion into urine and feces from five males injected with hCG and comparison between 10 males and 10 females). Radiolabelled metabolites of 14C-testosterone were excreted, 84.7+/-4.2 % in urine and 15.2+/-3.9 % in feces. A total of 82.7+/-4.2% of urinary and 45.7+/-13.6% of fecal radioactivity was excreted over the first 24 h period post-infusion (metabolite concentration peaked at 8.2+/-2.5 h and 22.0+/-7.0 h, respectively). Several urinary and fecal androgen metabolites were separated by HPLC but only fecal metabolites were associated with native testosterone; however, there was immunoreactivity in more than one metabolite derived from 14C-testosterone. After hCG administration, an increase in androgen metabolite excretion was observed (p<0.05). Males excreted greater amounts daily of urinary androgen metabolites as compared with females (p<0.05); this difference was not evident in feces. Results of the present study indicate that the procedure used is a reliable and non-invasive method to repeatedly monitor variations in testicular endocrine activity in this species. It can be a useful tool that would help ensure the survival of the wild populations as well as to provide the basis for a more efficient use by the fur industry.

Effects of alcohol and cigarette consumption on human seminal quality.

OBJECTIVE: To evaluate the effects of alcohol or cigarette consumption on seminal parameters in a large population of men attending an andrology laboratory. DESIGN: Analysis of ten years of data (1990-1999). SETTING: Andrology and Reproduction Laboratory (Córdoba, Argentina). PATIENT(S): Patients (3,976) were grouped according to nonsmokers; <==20 cigarettes/day; >20 cigarettes/day; nonalcohol consumers; <==500 mL of wine ( approximately 52 g of ethanol) or equivalent/day; and >500 mL of wine or equivalent/day. Patients who drank alcohol and smoked were also considered. INTERVENTION(S): A questionnaire was voluntarily filled out by patients. It provided data on drug consumption and genitourinary diseases. MAIN OUTCOME MEASURE(S): Seminal volume, sperm concentration, motility, viability, and morphology. RESULTS: No statistical differences in seminal parameters were found between the degrees of alcohol or tobacco consumption; so, independently of the degree of consumption patients were considered as smokers or alcohol consumers. CONCLUSION(S): Alcohol or cigarette consumption did not alter the seminal parameters. Nevertheless, when the patients with these two habits were compared to those without these habits, a significant reduction in seminal volume, sperm concentration, percentage of motile spermatozoa, and a significant increase of the nonmotile viable gametes were detected. The synergic or additive effect of these two toxic habits is discussed.

Effects of PDC-109 on bovine sperm functional activity in presence or absence of heparin.

PDC-109, a heparin-binding protein (from the seminal vesicles) that binds to sperm surface phospholipids at ejaculation, may modulate several aspects of sperm activity. The objectives of the present study were to determine: (1) in the presence or absence of heparin, the effects of exogenous PDC-109 on sperm motility (Makler chamber), viability (Hoechst 33258) and membrane functional integrity (hypoosmotic swelling test) of bovine spermatozoa; (2) the role of PDC-109 as a capacitation-inducing factor; and (3) its ability to induce the acrosome reaction (fluorescein staining). After 4-h capacitation in the presence of heparin, the addition of PDC-109 (0.5, 1.5 or 3.0mg/ml) significantly decreased the percentages of motile, progressive, and viable cells; these effects were also detected in the absence of heparin. However, PDC-109 elicited a twofold increase (from 14 to 28%) in the proportion of acrosome-reacted spermatozoa, but only in the presence of heparin. Progesterone (10 microM) or angiotensin II (100 or 1000 nM) stimulated the acrosome reaction after capacitation in the presence of PDC-109 without heparin (from 10 to 17, 23 and 22%, respectively). In conclusion, PDC-109 appears to modulate sperm functional activity, with some effects manifest in the absence of heparin.