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Espino J.,University of Extremadura | Bejarano I.,University of Extremadura | Ortiz A.,Extremadura Center for Human Assisted Reproduction | Lozano G.M.,Extremadura Center for Human Assisted Reproduction | And 3 more authors.
Fertility and Sterility | Year: 2010

It is assumed somatic cells can die in the apoptotic, the autophagic, or the necrotic way; however, the mechanisms of sperm death are not clear. Here, ejaculated human spermatozoa were evaluated for apoptosis and reactive oxygen species production in the absence or presence of melatonin, and we concluded that melatonin reverses sperm apoptosis due to its free radical scavenging actions. Copyright © 2010 American Society for Reproductive Medicine, Published by Elsevier Inc. Source


Espino J.,University of Extremadura | Ortiz A.,Extremadura Center for Human Assisted Reproduction | Bejarano I.,University of Extremadura | Lozano G.M.,Extremadura Center for Human Assisted Reproduction | And 4 more authors.
Fertility and Sterility | Year: 2011

Objective: To evaluate whether the protective effect of melatonin on H 2O2-induced caspase activation and DNA fragmentation depends on the interaction between melatonin and its surface receptors. Design: Laboratory study. Setting: Center for assisted human reproduction at a Spanish hospital. Patient(s): Twenty-one healthy donors. Intervention(s): Human spermatozoa were treated with increasing concentrations of hydrogen peroxide (H2O2; 1μM, 10 μM, 100 μM, 1mM) and preincubated with 1 mM melatonin. Main Outcomes Measure(s): Activation of caspase-3 and -9 as well as DNA fragmentation were examined by fluorescence methods. Result(s): Our findings showed that H2O2 induced a significant increase in caspase-9 and caspase-3, which was dose independent. Conversely, pretreatment with melatonin reduced H2O2-mediated caspase activation in a dose-dependent way. Moreover, the antiapoptotic effects of melatonin in ejaculated human spermatozoa may involve membrane melatonin receptor MT1. In addition, we found that the survival-promoting pathway extracellular signal-regulated kinase (ERK) is likely to have a role in the protective actions of melatonin in ejaculated human spermatozoa. Finally, we confirmed these results further by demonstrating that melatonin prevention of H 2O2-induced DNA fragmentation is dependent on both MT1 receptor and ERK signaling. Conclusion(s): These results indicate that the stimulation with melatonin triggers a set of events culminating in cell death prevention in ejaculated human spermatozoa. © 2011 by American Society for Reproductive Medicine. Source


Ortiz A.,Extremadura Center for Human Assisted Reproduction | Espino J.,University of Extremadura | Bejarano I.,University of Extremadura | Lozano G.M.,Extremadura Center for Human Assisted Reproduction | And 4 more authors.
Journal of Pineal Research | Year: 2011

Abstract: Although human seminal fluid contains melatonin and spermatozoa reportedly possess membrane melatonin receptors, there are no experimental studies that have ascertained the relationship between melatonin and male infertility. This study evaluated whether urinary 6-sulfatoxymelatonin and urinary total antioxidant capacity correlate with different seminal parameters including sperm concentration, motility and morphology. Also, the in vitro effects of melatonin on human sperm motility were investigated. Semen samples from 52 men who were counselled for infertility were obtained. Sperm concentration was determined using the haemocytometer method, motility kinematic parameters were assessed using a computer-aided semen analysis system, while morphology and vitality were evaluated after Diff-Quick and Eosin-Nigrosin vital staining, respectively. For the quantification of urinary 6-sulfatoxymelatonin, a commercial ELISA kit was used, and urinary total antioxidant capacity was evaluated by means of a colorimetric assay kit. For the in vitro effects of melatonin, samples were incubated for 30 min in the presence or absence of 1 mm melatonin. Both urinary 6-sulfatoxymelatonin and total antioxidant capacity levels positively correlated with sperm concentration, motility and morphology, as well as negatively correlated with the number of round cells. Additionally, 30-min exposure of sperm to 1 mm melatonin improved the percentage of motile and progressively motile cells and decreased the number of static cells, thereby promoting the proportion of rapid cells. Therefore, melatonin improves semen quality, which is important because melatonin supplementation may be potentially used to obtain a successful assisted reproductive technique outcome. © 2010 John Wiley & Sons A/S. Source


Ortiz A.,Extremadura Center for Human Assisted Reproduction | Espino J.,University of Extremadura | Bejarano I.,University of Extremadura | Lozano G.M.,Extremadura Center for Human Assisted Reproduction | And 4 more authors.
Reproductive Biology and Endocrinology | Year: 2010

Background: Serotonin is a neurotransmitter that modulates a wide range of neuroendocrine functions. However, excessive circulating serotonin levels may induce harmful effects in the male reproductive system. The objective of this study was to evaluate whether the levels of urinary 5-hydroxyindoleacetic acid (5-HIIA), a major serotonin metabolite, correlate with different classical seminal parameters.Methods: Human ejaculates were obtained from 40 men attending infertility counselling and rotating shift workers by masturbation after 4-5 days of abstinence. Urinary 5- HIIA concentration was quantified by using a commercial ELISA kit. Forward motility was assessed by a computer-aided semen analysis (CASA) system. Sperm concentration was determined using the haemocytometer method. Sperm morphology was evaluated after Diff-Quik staining, while sperm vitality was estimated after Eosin-Nigrosin vital staining.Results: Our results show that urinary 5-HIIA levels obtained from a set of 20 volunteers negatively correlated with sperm concentration, forward motility, morphology normal range and sperm vitality. On the other hand, we checked the relationship between male infertility and urinary 5-HIIA levels in 20 night shift workers. Thus, urinary 5-HIIA levels obtained from 10 recently-proven fathers were significantly lower than those found in 10 infertile males. Additionally, samples from recent fathers exhibited higher sperm concentration, as well as better forward motility and normal morphology rate.Conclusions: In the light of our findings, we concluded that high serotonin levels, indirectly measured as urinary 5-HIIA levels, appear to play a role as an infertility determinant in male subjects. © 2010 Ortiz et al; licensee BioMed Central Ltd. Source

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