ABSTRACT
It has been demonstrated that food intake and reproductive physiology are both simultaneously modulated to optimize reproductive success under fluctuating metabolic conditions. Ghrelin (GHRL) is an orexigenic peptide identified as the endogenous ligand of the growth hormone secretagogue receptor that is being investigated for its potential role on reproduction. Considering that data available so far are still limited and characterization of GHRL action mechanism on the reproductive system has not been fully elucidated, we studied the participation of hypothalamus in GHRL effects on sperm functional activity, plasma levels of gonadotropins and histological morphology in mice testes after hypothalamic infusion of 0.3 or 3.0 nmol/day GHRL or artificial cerebrospinal fluid (ACSF) at different treatment periods. We found that GHRL 3.0 nmol/day administration for 42 days significantly reduced sperm concentration (GHRL 3.0 nmol/day = 14.05 ± 2.44 × 106/mL vs ACSF = 20.33 ± 1.35 × 106/mL, P < 0.05) and motility (GHRL 3.0 nmol/day = 59.40 ± 4.20% vs ACSF = 75.80 ± 1.40%, P < 0.05). In addition, histological studies showed a significant decrease percentage of spermatogonia (GHRL 3.0 nmol/day = 6.76 ± 0.68% vs ACSF = 9.56 ± 0.41%, P < 0.05) and sperm (GHRL 3.0 nmol/day = 24.24 ± 1.92% vs ACSF = 31.20 ± 3.06%, P < 0.05). These results were associated with a significant reduction in luteinizing hormone and testosterone plasma levels (P < 0.05). As GHRL is an orexigenic peptide, body weight and food intake were measured. Results showed that GHRL increases both parameters; however, the effect did not last beyond the first week of treatment. Results presented in this work confirm that central GHRL administration impairs spermatogenesis and suggest that this effect is mediated by inhibition of hypothalamic-pituitary-gonadal axis.
Subject(s)
Ghrelin/physiology , Gonadotropins, Pituitary/blood , Hypothalamus/physiology , Spermatogenesis , Testosterone/blood , Animals , Body Weight , Eating , Male , Mice , Spermatozoa/physiology , Testis/ultrastructureABSTRACT
In order to clarify the physiological role of ghrelin in gestation, we evaluated the effects of administration of exogenous ghrelin (2 or 4ânmol/animal per day) or its antagonist (6ânmol/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 12âh after copulation, mice were killed at day 18 of gestation; ii) since ovulation induction until 80âh 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 (4ânmol/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.
Subject(s)
Embryo Implantation/drug effects , Embryo, Mammalian/cytology , Embryo, Mammalian/drug effects , Fertilization/drug effects , Ghrelin/pharmacology , Animals , Copulation , Corpus Luteum/cytology , Corpus Luteum/drug effects , Female , Fertilization/physiology , Mice , PregnancyABSTRACT
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 Organization's 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., > or = 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.
Subject(s)
Alcohol Drinking/adverse effects , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Aspirin/adverse effects , Smoking/adverse effects , Sperm Count , Sperm Motility , Adult , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Aspirin/therapeutic use , Humans , Infertility, Male/etiology , Male , Students, Medical , Testosterone/bloodABSTRACT
La alta incidencia de factor masculino en los casos de esterilidad conyugal justifican los intentos de un estudio más completo del semen. La prueba de resistencia osmótica (PRO), ha sido propuesta como un detector precoz de fallas en la integridad funcional de la membrana espermática. En el presente trabajo estudiamos las posibles correlaciones entre PRO y los parámetros convencionales del espermograma (de acuerdo a las técnicas recomendadas por la OMS) y comparamos los resultados de la PRO en especímenes normospérmicos y oligo, terato y/o astenospérmicos. En 75 casos se cuantificó: concentración espermática (en hemocitómetro), motilidad, velocidad de traslación (rápidos, lentos y no progresivos), morfología (coloración de Papanicolaou) y PRO (incubación del semen en solución de citrato de Na y fructosa, 150 mOsm/l, 37ºC, 60 min). En todos los casos, la PRO se correlacionó significativamente con el porcentaje de formas móviles, rápidas o de morfología normal (r = 0.39; r = 0.39 y r = 0.35 respectivamente). A su vez, disminuye significativamente al incrementarse el número de alteraciones en las determinaciones del espermograma de rutina. En las muestras asteno, terato y oligospérmicas, los resultados de la PRO son significativamente inferiores a las con motilidad, morfología o concentración normal, respectivamente (p < 0.005 en todos los casos). Consideramos que la PRO representa una técnica accesible y de relativa sencillez que constituye un aporte relevante en el diagnóstico de la esterilidad masculina (AU)
Subject(s)
Comparative Study , Humans , Male , Adult , Infertility, Male/diagnosis , Semen/cytology , Sperm-Ovum Interactions/physiology , Cell Membrane/drug effects , Osmotic Fragility/drug effects , Infertility, Male/etiology , Semen/physiology , Spermatozoa/cytology , Spermatozoa/drug effects , Spermatozoa/physiologyABSTRACT
La alta incidencia de factor masculino en los casos de esterilidad conyugal justifican los intentos de un estudio más completo del semen. La prueba de resistencia osmótica (PRO), ha sido propuesta como un detector precoz de fallas en la integridad funcional de la membrana espermática. En el presente trabajo estudiamos las posibles correlaciones entre PRO y los parámetros convencionales del espermograma (de acuerdo a las técnicas recomendadas por la OMS) y comparamos los resultados de la PRO en especímenes normospérmicos y oligo, terato y/o astenospérmicos. En 75 casos se cuantificó: concentración espermática (en hemocitómetro), motilidad, velocidad de traslación (rápidos, lentos y no progresivos), morfología (coloración de Papanicolaou) y PRO (incubación del semen en solución de citrato de Na y fructosa, 150 mOsm/l, 37§C, 60 min). En todos los casos, la PRO se correlacionó significativamente con el porcentaje de formas móviles, rápidas o de morfología normal (r = 0.39; r = 0.39 y r = 0.35 respectivamente). A su vez, disminuye significativamente al incrementarse el número de alteraciones en las determinaciones del espermograma de rutina. En las muestras asteno, terato y oligospérmicas, los resultados de la PRO son significativamente inferiores a las con motilidad, morfología o concentración normal, respectivamente (p < 0.005 en todos los casos). Consideramos que la PRO representa una técnica accesible y de relativa sencillez que constituye un aporte relevante en el diagnóstico de la esterilidad masculina
