RESUMEN
Aiming to investigate trends in seminal parameter values among Brazilian men between 1995 and 2018, we performed a retrospective analysis of spermograms of couples admitted for infertility testing at UNICAMP/Brazil. For the present study, only the first sample produced by each man was analyzed (9,267 samples). Total motile sperm count (TMSC), percentage of spermatozoa with normal morphology (NM), and sperm concentration after seminal processing (SCA) were considered dependent variables. Statistical analysis was carried out through linear regression for the median values both in the general population and in the population categorized by age group (<30, 30-39, and ≥40 years). During the study period, the mean age of men was 32.46 (± 6.48) years, with a median of 32 (18-67) years. We found a significant decrease in the median values of TMSC (reduction of 2.84 million/year), NM (reduction of 0.52% each year) and SCA (reduction of 0.24 million/mL each year). In conclusion, we observed that Brazilian men undergoing infertility investigation had a decline in seminal parameters in the past 23 years. Surveillance should be maintained in the coming years, and further studies are needed to elucidate possible causes for seminal deterioration and to devise strategies to reverse this trend.
Asunto(s)
Semen/metabolismo , Adulto , Brasil , Humanos , Modelos Lineales , Masculino , Manejo de Especímenes , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides/citologíaRESUMEN
BACKGROUND: The objectives were firstly to assess acrosome reaction (AR) status of spermatozoa following uterine flushing, secondly to measure levonorgestrel (LNG) levels in serum and in uterine flushing fluid and finally to measure endometrial glycodelin-A expression after administration of LNG as a form of emergency contraception (EC). METHODS: Forty-eight experiments were conducted on 15 regularly menstruating women. Four groups were formed based on different intercourse to treatment interval and treatment to recovery of spermatozoa and the biopsies. RESULTS: Twenty-four and forty-eight hours after treatment, there were 14.5 +/- 3.9 x 10(6) and 17.3 +/- 6.8 x 10(6) sperm recovered from the uterus, respectively. There were no differences between the AR rate and the endometrial glycodelin-A staining intensity in an LNG or placebo treated cycles. The LNG in uterine flushing medium represented 1.38% of the values observed in serum 24 h after the LNG intake. CONCLUSIONS: Twenty-four and forty-eight hours after administration of EC, neither the proportion of AR sperm, nor the glycodelin-A level was influenced by 1.5 mg of LNG. LNG did not impair the cervical mucus either because viable spermatozoa were found in the genital tract 36-60 h after coitus and 24-48 h after LNG intake. The mechanism of action of LNG as EC remains unknown.
Asunto(s)
Reacción Acrosómica/fisiología , Anticoncepción Postcoital , Anticonceptivos Sintéticos Poscoito/administración & dosificación , Endometrio/metabolismo , Glicoproteínas/biosíntesis , Levonorgestrel/administración & dosificación , Proteínas Gestacionales/biosíntesis , Adulto , Método Doble Ciego , Endometrio/efectos de los fármacos , Femenino , Glicodelina , Humanos , Levonorgestrel/sangre , MasculinoRESUMEN
BACKGROUND: The levonorgestrel-releasing intrauterine system (LNG-IUS) exerts its contraceptive effect by interfering with sperm transport through the female genital tract and with ovulation. However, the possibility cannot be discarded that the device exerts a direct effect on sperm function, thus, helping prevent fertilization. OBJECTIVES: The purpose of this study is to evaluate whether LNG at doses comparable to that measured in the uterus during the use of the LNG-IUS affects the detection of D-mannose binding sites or zona pellucida (ZP) receptors on human spermatozoa. The association with acrosomal status was also investigated. METHODS: Seventeen semen samples from fertile men were used, and spermatozoa were separated using a Percoll gradient and incubated for 22 h at 37 degrees C under 5% CO(2) in air. Capacitated spermatozoa were exposed for 30 min to 1,000 or 10,000 ng/mL of LNG or control medium. D-Mannose binding sites were detected using commercial D-mannosylated bovine serum albumin conjugated with fluorescein isothiocyanate, and the percentage of specific patterns (II and III) was recorded. The acrosome reaction was evaluated using the Pisum sativum technique. RESULTS: Levonorgestrel releasing significantly increased (p < .001) the percentage of spermatozoa with D-mannose receptors localized in pattern III, and this increase was dose dependent and a significant increase (p < .001) in the percentage of acrosome-reacted spermatozoa. Double staining confirmed an association between the location of the zona receptor and acrosomal status. RESULTS: The in vitro exposure of capacitated spermatozoa to the assayed doses of LNG increased the proportion of spermatozoa with fewer chances of interacting with the ZP. Further studies should be carried out to confirm whether this mechanism is part of the contraceptive action of the LNG-IUS.
Asunto(s)
Anticonceptivos Femeninos/administración & dosificación , Levonorgestrel/administración & dosificación , Espermatozoides/efectos de los fármacos , Útero/efectos de los fármacos , Zona Pelúcida/metabolismo , Reacción Acrosómica/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Fluoresceína-5-Isotiocianato/análogos & derivados , Colorantes Fluorescentes , Humanos , Lectinas Tipo C/análisis , Lectinas Tipo C/efectos de los fármacos , Masculino , Manosa/metabolismo , Receptor de Manosa , Lectinas de Unión a Manosa/análisis , Lectinas de Unión a Manosa/efectos de los fármacos , Receptores de Superficie Celular/análisis , Receptores de Superficie Celular/efectos de los fármacos , Albúmina Sérica Bovina , Capacitación Espermática , Espermatozoides/química , Espermatozoides/metabolismoRESUMEN
INTRODUCTION: The aim of this study was to evaluate the effect of three concentrations of levonorgestrel (LNG) comparable to the levels found in serum following ingestion of LNG as emergency contraception (EC) on the acrosome reaction (AR) of capacitated and noncapacitated spermatozoa of fertile men. MATERIALS AND METHODS: A total of 24 semen samples from three fertile men were evaluated. The spermatozoa were selected by Percoll gradient. Twelve samples were subsequently incubated with human tubal fluid medium supplemented with bovine serum albumin (HTF/BSA) for 20 h under capacitating conditions. The capacitated spermatozoa and the spermatozoa from the remaining 12 samples were exposed to LNG at 1, 10 and 100 ng/mL, to follicular fluid (FF) (20 %v/v) and to HTF medium. The ratio of live to dead spermatozoa was assessed after 1, 2 and 3 h of incubation at 37 degrees C and 5% CO2. After 30 min of exposure to the different LNG concentrations, aliquots were divided into two parts. In the first part, spermatozoa were immediately stained with Hoescht 33258 and fluorescein isothiocyanate-pisum sativum agglutinin (FITC-PSA) in order to assess AR rate and to repeat evaluation of the live-to-dead ratio. After 3 h of incubation, the remaining part of the aliquots were submitted to the same procedures. Each concentration of LNG was then compared with FF and HTF medium as positive and negative controls, respectively. RESULTS: The results showed that in vitro exposure to the three different LNG concentrations did not induce AR. CONCLUSION: This study failed to show any in vitro effect on AR of LNG concentrations similar to those found in serum following intake of LNG as EC. If this effect exists or if there is any other that influences sperm fertilizing capacity, in vitro experiments are probably not an appropriate way of testing it.
Asunto(s)
Reacción Acrosómica/efectos de los fármacos , Anticonceptivos Femeninos/farmacología , Levonorgestrel/farmacología , Espermatozoides/efectos de los fármacos , Trompas Uterinas , Femenino , Líquido Folicular , Humanos , Masculino , Motilidad Espermática/efectos de los fármacosRESUMEN
The objectives of this study were to assess the expression of alpha-d-mannose binding sites in human spermatozoa, human sperm-oocyte interaction and the development of early stages of mouse embryo in the presence of levonorgestrel (LNG). Semen samples were obtained from 16 normozoospermic men. Spermatozoa were separated by Percoll gradient and incubated overnight for capacitation. The kinetic analysis of the expression of alpha-D-mannose binding sites was determined at 0, 4 and 22 h and in 22 h-capacitated spermatozoa that had been exposed to 1, 10 or 100 ng/mL of LNG or to a control medium for 30 min. Sperm binding sites for alpha-D-mannose were detected using commercial alpha-D-mannosylated bovine serum albumin conjugated with fluorescein isothiocyanate. To evaluate sperm-oocyte interaction, each oocyte was placed in a 100-microL droplet containing one of the three doses of LNG or control medium and inseminated with 1.0 x 10(5) motile spermatozoa/mL, after which the number of bound spermatozoa was evaluated. A total of 157 two-cell embryos recovered from eight mice was pooled and assigned randomly to treatment (1, 10 or 100 ng/mL of LNG) or control groups. There was a significant increase in the expression of specific alpha-d-mannose binding sites (Patterns II and III) during the incubation of spermatozoa under capacitating conditions. In the presence of LNG, results showed that there was no significant difference in the expression of specific alpha-d-mannose binding sites (Patterns II and III) at any LNG concentration tested compared with those spermatozoa in control medium. None of the LNG concentrations were capable of modifying the number of spermatozoa tightly bound to the human zona pellucida. There was no association between the presence or absence of LNG or the different doses of LNG evaluated and mouse embryo development. In conclusion, the hypothesis that in vitro exposure to LNG could interfere with sperm function and could contribute to the mechanism of action of this form of contraception was not confirmed but cannot be ruled out by the results of this study.