Actualización sobre COVID-19 e histofisiología del sistema reproductor masculino / Update on COVID-19 and histophysiology of the male reproductive system

RESUMEN: La reciente pandemia de la COVID-19 ha sacudido a la sociedad teniendo una importante repercusión en el campo de la salud y de la investigación. Dada su relevancia, se han llevado a cabo estudios sobre los efectos del SARS-CoV-2 en la fisiología humana. En concreto, sobre la posible presencia y transmisión del virus a través del sistema reproductor masculino y su posible efecto en el éxito reproductivo. Conocer si la presencia del virus altera los órganos responsables del desarrollo y maduración de las células de la serie espermatogénica podría revelarnos su implicación en la calidad seminal. Por ello, nos planteamos esta revisión, con el fin de analizar las principales evidencias científicas sobre los efectos del SARS-CoV-2 en la histofisiología del sistema reproductor masculino y sobre la capacidad fecundante de los espermatozoides.

SUMMARY: The recent COVID-19 pandemic has shaken up society, having a significant impact on the field of health and research. Given its relevance, studies have been performed on the effects of SARS-CoV-2 on human physiology. In particular, the possible presence and transmission of the virus through the male reproductive system could affect reproductive success. Knowing if the presence of the virus disrupts the organs responsible for the development and maturation of the cell lines involved in spermatogenesis could reveal its implications in sperm quality. For that reason, we proposed this review, in order to analyze the main scientific evidence on the effects of SARS-CoV-2 on the histophysiology of the male reproductive system and sperm fertilizing capacity.

Spermic Toxicity Test of Medical Devices for Human Assisted Reproductive Technology / 中国医疗器械杂志

In order to provide a thorough summary and analysis over sperm toxicity evaluation of medical devices for human

Distribution of DNA damage in the human sperm nucleus: Implications of the architecture of the sperm head / 亚洲男科学杂志(英文版)

The sperm nucleus is prone to sustain DNA damage before and after ejaculation. Distribution of the damage is not homogeneous, and the factors determining differential sensitivity among nuclear regions have not yet been characterized. Human sperm chromatin contains three structural domains, two of which are considered the most susceptible to DNA damage: the histone bound domain, harboring developmental related genes, and the domain associated with nuclear matrix proteins. Using a quantitative polymerase chain reaction (qPCR) approach, we analyzed the number of lesions in genes homeobox A3 (HOXA3), homeobox B5 (HOXB 5), sex-determining region Y (SRY)-box 2 (SOX2), β-GLOBIN, rDNA 18S, and rDNA 28S in human sperm after ultraviolet irradiation (400 μW cm-2, 10 min), H2O2treatment (250 mmol l-1, 20 min), and cryopreservation, which showed differential susceptibility to genetic damage. Differential vulnerability is dependent on the genotoxic agent and independent of the sperm nuclear proteins to which the chromatin is bound and of accessibility to the transcription machinery. Immunodetection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) showed that the highest level of oxidation was observed after H2O2treatment. The distribution of oxidative lesions also differed depending on the genotoxic agent. 8-OHdG did not colocalize either with histone 3 (H3) or with type IIα + β topoisomerase (TOPO IIα + β) after H2O2treatment but matched perfectly with peroxiredoxin 6 (PRDX6), which is involved in H2O2metabolism. Our study reveals that the characteristics of the sperm head domains are responsible for access of the genotoxicants and cause differential degree of damage to nuclear areas, whereas chromatin packaging has a very limited relevance. The histone-enriched genes analyzed cannot be used as biomarkers of oxidative DNA damage.

Rho/ROCK signaling pathway and anti-cryodamage ability of human sperm / 中华男科学杂志

Objective@#To investigate the influence of the Rho/ROCK signaling pathway on the anti-cryodamage ability of human sperm and provide some theoretical evidence for the development of high-efficiency semen cryoprotectants.@*METHODS@#We collected semen samples from 25 healthy males, each divided into a fresh, a normal cryopreservation control and an Rho-inhibition group. Before and after freezing, we detected sperm motility, viability, membrane integrity, morphology, DNA fragmentation index (DFI), acrosomal enzyme activity (AEA) and mitochondrial membrane potential (MMP) and determined the expressions of RhoA and ROCK proteins in the sperm by immunofluorescence staining.@*RESULTS@#Compared with the normal cryopreservation control, the frozen-thawed sperm of the Rho-inhibition group showed significantly increased sperm motility （ ［51.20 ± 7.70］% vs ［57.50 ± 6.83］%, P = 0.002), survival rate ( ［52.87 ± 5.07］% vs ［60.24 ± 5.53］%, P = 0.001), membrane integrity (［59.78±5.56］% vs ［67.10 ± 4.43］%, P = 0.001), percentage of morphologically normal sperm (［4.83 ± 1.11］% vs ［7.46 ± 1.28］, P = 0.001) and MMP (56.30 ± 4.28 vs 63.11 ± 2.97, P = 0.001), but decreased DFI (［27.64 ± 6.64］% vs ［18.87 ± 4.07］%, P = 0.001). There was no statistically significant difference in the AEA of the frozen-thawed sperm between the control and Rho-inhibition groups (97.65 ± 9.31 vs 98.30 ± 11.33, P > 0.05). Immunofluorescence staining revealed extensive expressions of RhoA and ROCK proteins in the head and neck of the sperm.@*CONCLUSIONS@#The Rho/ROCK signaling pathway plays a role in the cryodamage to human sperm, and inhibiting the activity of Rho/ROCK can significantly improve the ability of sperm to resist cryodamage.

Increased cryo-survival rate in ejaculated human sperm from infertile men following pre-freeze in vitro myo-inositol supplementation / 대한생식의학회지

OBJECTIVE: To investigate the effects of in vitro myo-inositol (Myo-Ins) supplementation of cryopreserved human semen on the cryo-survival rate (CSR). METHODS: Semen samples were obtained from 41 infertile men. Following routine semen analysis, each sample was divided into two equal aliquots (0.5 mL each). One aliquot was treated with 1 mg of Myo-Ins dissolved in 10 µL of sperm preparation medium. The second aliquot was treated with 10 µL of the same medium (control). Both aliquots were incubated for 20 minutes prior to freezing to slow the freezing process. The frozen samples were examined for post-thaw percentages of total motility (TM), progressive motility (PM), and the CSR, defined as the percentage of post-thaw TM divided by the percentage of pre-freeze TM and multiplied in 100. The results were expressed as median and interquartile range (25th and 75th percentiles). RESULTS: The pre-freeze TM (50% [30%–50%]) and PM (35% [20%–35%]) were significantly higher than the post-thaw TM and PM in the Myo-Ins group (15% [10%–35%] and 10% [5%–20%]; p < 0.001 and p < 0.001, respectively) and the control group (10% [6%–30%] and 5% [3%–15%]; p < 0.001 and p < 0.001, respectively). The CSR of the 41 semen aliquots supplemented with Myo-Ins (40% [25%–70%]) was significantly higher than that of the control samples (30% [13%–58%], p=0.041). The CSR of the 26 abnormal semen samples that were supplemented with Myo-Ins (38% [20%–50%]) was significantly higher than that of the control samples (23% [12%–30%], p=0.031). CONCLUSION: In vitro Myo-Ins supplementation of ejaculated human sperm from infertile men resulted in a significant increase in the CSR in samples with abnormal pre-freeze sperm parameters.

Advantages of cryopreservation technology for rare human sperm / 中华男科学杂志

<p><b>Objective</b>To search for an effective method for cryopreservation of rare human sperm (RHS) by comparing the effect of RHS cryopreservation technology with that of conventional cryopreservation technology on post-thaw sperm from patients with severe oligozoospermia.</p><p><b>METHODS</b>Semen samples obtained from 82 patients with severe oligozoospermia were preserved by RHS cryopreservation technology, and another 24 samples cryopreserved by conventional technology, the former divided into groups A (sperm concentration < 1×10⁶/ml, n = 54) and B (1×10⁶/ml ≤ sperm concentration < 5×10⁶/ml, n = 28), and the latter included in group C (sperm concentration < 15×106 /ml, n = 24). The survival rate of post-thaw sperm and recovery rate of progressively motile sperm (PMS) were compared among the three groups.</p><p><b>RESULTS</b>The survival rate of post-thaw sperm was significantly higher in groups A and B than in C (［62.8 ± 18.7］% and ［61.9 ± 17.2］% vs ［50.7 ± 13.5］%, P < 0.05), and so was the recovery rate of PMS (［68.7 ± 18.4］% and ［70.7 ± 15.5］% vs ［29.2 ± 12.4］% , P < 0.05), but there were no statistically significant differences between groups A and B in either of the two parameters (P > 0.05).</p><p><b>CONCLUSIONS</b>The cryopreservation technology for rare human sperm may yield relatively stable post-thaw results and deserves a wide clinical application in preserving male fertility.</p>

Povidone-iodine versus the benzethonium chloride wipe for penile skin disinfection before semen collection from sperm donors / 中华男科学杂志

<p><b>Objective</b>To study the influence of povidone-iodine (PI) versus that of the benzethonium chloride wipe (BCW) on semen collection and semen quality of sperm donors undergoing penile skin disinfection and provide some evidence for the selection of disinfection methods for semen collection.</p><p><b>METHODS</b>We used PI from August to December 2015 and BCWs from January to July 2016 for penile skin disinfection before semen collection, with two samples from each donor, one collected with and the other without penis skin disinfection (the blank control group). After semen collection, we conducted a questionnaire investigation on the influence of the two disinfection methods on semen collection and compared the semen parameters between the two groups of sperm donors.</p><p><b>RESULTS</b>Totally, 185 sperm donors were included in this study, of whom 63 underwent penile skin disinfection with PI and the other 122 with BCWs before semen collection. Statistically significant differences were found between the PI and BCW groups in the adaptability to the disinfectant and rigid disinfection procedures (P <0.05), but not in the other items of the questionnaire (P >0.05). Compared with the sperm donors of the blank control group, those of the PI group showed statistically significant difference in the percentage of progressively motile sperm (PMS) (［63.02 ± 3.18］% vs ［61.45 ± 4.78］%, P<0.05), but not in the abstinence time (［4.97 ± 1.79］ vs ［4.7 ± 0.94］ d, P >0.05), semen volume (［4.11 ± 1.54］ vs ［4.15 ± 1.61］ ml, P >0.05), sperm concentration (［110 ± 29.6］ vs ［107.5 ± 31.79］ ×10⁶/ml, P >0.05), or total sperm count (［439.10 ± 170.13］ vs ［434.02 ± 186.91］ ×106/ejaculate, P >0.05), while those of the BCW group exhibited no remarkable difference in any of the above parameters (P >0.05). Among the samples with abnormal semen quality, significantly fewer were found with abnormal PMS in the BCW than in the PI group (1.64% ［2/122］ vs 9.68% ［6/62］, P <0.05). However, there were no significant differences between the PI and BCW groups in the abnormal semen volume, abnormal sperm concentration, or the rate of semen bacterial contamination (P >0.05).</p><p><b>CONCLUSIONS</b>Before semen collection from donors, penile skin disinfection with povidone-iodine may affect both the semen collection process and the quality of donor sperm, while the benzethonium chloride wipe can reduce the influence on the semen collection process and does not affect the semen parameters.</p>

Human sperm testicular angiotensin-converting enzyme helps determine human embryo quality / 亚洲男科学杂志(英文版)

Angiotensin-converting enzyme functions in the male reproductive system, but the extent of its function in reproduction is not fully understood. The primary objective of this work was to investigate the relationship between the testicular isoform of angiotensin-converting enzyme present in human spermatozoa and semen parameters, human embryo quality, and assisted reproduction success. A total of 81 semen samples and 635 embryos from couples undergoing oocyte donation cycles at the IVI Bilbao Clinic were analyzed. Semen parameters, embryos quality, and blastocyst development were examined according to the World Health Organization standards and the Spanish Association of Reproduction Biology Studies criteria. The percentage of testicular angiotensin-converting enzyme-positive spermatozoa and the number of molecules per spermatozoon were analyzed by flow cytometry. Both parameters were inversely correlated with human sperm motility. Higher percentages of testicular angiotensin-converting enzyme-positive spermatozoa together with fewer enzyme molecules per spermatozoon were positively correlated with better embryo quality and development. Our results suggest that embryos with a higher implantation potential come from semen samples with higher percentages of testicular angiotensin-converting enzyme-positive cells and fewer enzyme molecules per spermatozoon. Based on these findings, we propose that testicular angiotensin-converting enzyme could be used to aid embryologists in selecting better semen samples for obtaining high-quality blastocysts during in vitro fertilization procedures.

Human sperm testicular angiotensin-converting enzyme helps determine human embryo quality / 亚洲男科学杂志(英文版)

Angiotensin-converting enzyme functions in the male reproductive system, but the extent of its function in reproduction is not fully understood. The primary objective of this work was to investigate the relationship between the testicular isoform of angiotensin-converting enzyme present in human spermatozoa and semen parameters, human embryo quality, and assisted reproduction success. A total of 81 semen samples and 635 embryos from couples undergoing oocyte donation cycles at the IVI Bilbao Clinic were analyzed. Semen parameters, embryos quality, and blastocyst development were examined according to the World Health Organization standards and the Spanish Association of Reproduction Biology Studies criteria. The percentage of testicular angiotensin-converting enzyme-positive spermatozoa and the number of molecules per spermatozoon were analyzed by flow cytometry. Both parameters were inversely correlated with human sperm motility. Higher percentages of testicular angiotensin-converting enzyme-positive spermatozoa together with fewer enzyme molecules per spermatozoon were positively correlated with better embryo quality and development. Our results suggest that embryos with a higher implantation potential come from semen samples with higher percentages of testicular angiotensin-converting enzyme-positive cells and fewer enzyme molecules per spermatozoon. Based on these findings, we propose that testicular angiotensin-converting enzyme could be used to aid embryologists in selecting better semen samples for obtaining high-quality blastocysts during in vitro fertilization procedures.

Toxic effects of polychlorinated biphenyls (Aroclor 1254) on human sperm motility / 亚洲男科学杂志(英文版)

Polychlorinated biphenyls (PCBs) are common environmental contaminants that represent a considerable risk to reproductive toxicity in exposed human populations. Although some experimental studies have suggested an association between the levels of PCBs and semen quality, the direct effects of PCBs on human sperm parameters remain largely unexplored. To this aim, a short-term in vitro incubation experiment that better imitated the putative exposure of sperm to Aroclor 1254 (a commercial PCB mixture) in male reproduction tissue was conducted. Human sperm were incubated with various concentrations (0, 1, 5, or 25 mg l-1) of Aroclor 1254 for different amounts of time (3 and 6 h) in vitro. Sperm motility parameters were analyzed with computer-assisted sperm analysis (CASA). The proportion of sperm with high mitochondrial membrane potential (ΔΨm) and the levels of intracellular reactive oxygen species (ROS) were detected to explore the probable cause of sperm impairment. Human sperm exposed to continuous Aroclor 1254 exhibited: (i) reduced sperm motility and kinematic parameters, (ii) a proportion of sperm with high ΔΨm that decreased in a dose-dependent manner (P < 0.05), and (iii) increased levels of ROS compared with controls (P < 0.05). In conclusion, Aroclor 1254 can decrease sperm motility, which may culminate in increased ROS and general mitochondrial dysfunction, thus affecting the fertilization potential of sperm. Our findings suggest a broader understanding of the effect of Aroclor 1254 on human sperm.

Fragmentación del ADN espermático: situación actual / Sperm DNA fragmentation: Current research

Resumen OBJETIVO: Revisar los mecanismos responsables de la fragmentación del ADN espermático y sus métodos de análisis, la definición de fragmentación del ADN y las características que hacen al espermatozoide único y diferente de las demás células. Discutir la trascendencia de las técnicas actuales para evaluar la fragmentación del ADN espermático, su utilidad y aplicación clínica. Emitir recomendaciones de práctica clínica según lo que el grupo considera el mejor abordaje en este tema. METODOLOGIA: Búsqueda bibliográfica en las bases de datos: Medline, Pubmed, Pubmed Central y Google Scholar con las palabras clave: fragmentación del ADN, fragmentación del ADN espermático, fragmentación del ADN espermático humano y pruebas de fragmentación del ADN. RESULTADOS: Se seleccionaron 143 artículos con adecuada metodología, claridad y relevancia clínica y se encontraron 16 metanálisis, de los que se seleccionaron 5 por su metodología y claridad en los resultados. CONCLUSIÓN: La integridad del genoma paterno es decisiva para conseguir un recién nacido sano. Las técnicas actuales están lejos de la perfección en términos de predictibilidad, selección y resultados. Sin embargo, las nuevas tecnologías pueden aportar información faltante para dilucidar el papel de las pruebas de fragmentación del ADN espermático en el laboratorio de reproducción asistida.

Abstract OBJECTIVE: To review the mechanisms responsible for sperm DNA fragmentation and its methods of analysis. This includes a briefly review about the definition of DNA fragmentation; what characteristics make the sperm unique and different from other cells. We also give a discussion about the impact of the current techniques to evaluate sperm DNA fragmentation and its utility and clinical application. Lastly, there are practice recommendations regarding what our group considers to be the best approach for this subject. METHODOLOGY: Bibliographic search in the databases: Medline, Pubmed, Pubmed Central and Google Scholar with the keywords: DNA fragmentation, sperm DNA fragmentation, fragmentation of human sperm DNA and DNA fragmentation tests. CONCLUSION: The integrity of the paternal genome is of crucial importance to reach our goal of a healthy newborn. Current techniques are far from perfect in terms of predictability, selection and results. New technologies may give us the information missing in order to elucidate the role of sperm DNA fragmentation tests in the assisted reproduction lab.

Efecto de la vitrificación de ovocitos humanos sobre la capacidad de unión y el estado acrosomal de espermatozoides humanos / Effect of the vitrification of human oocytes on the binding capacity and acrosome status of human sperm

Conocer los aspectos moleculares que acontecen en el proceso de unión de los espermatozoides humanos a la zona pelúcida (ZP) humana es uno de los grandes retos de la biología de la Reproducción. Por otra parte conocer si el proceso de fecundación puede verse afectado por la criopreservación de los gametos femeninos sigue siendo otra cuestión debatida en la literatura. En base a esto, el objetivo principal de este trabajo fue conocer si la vitrificación ovocitaria puede alterar la interacción de los espermatozoides con el glicocáliz de la ZP y demostrar si la ZP de estos ovocitos pierde la capacidad de inducir la reacción acrosómica en los espermatozoides. Según nuestros resultados el método de vitrificación ovocitaria cerrado (S3) no altera la capacidad de unión de los espermatozoides a la zona pelúcida, ni la capacidad de ésta para inducir la reacción acrosómica.

To know the molecular aspects that occur in the process of human sperm binding to the human zona pellucida (ZP) is one of the great challenges of reproduction biology. Moreover knowing if the fertilization process may be affected by cryopreservation of female gametes is still another issue discussed in the literature. Based on this, the main objective of this study was to determine whether the oocyte vitrification may alter the interaction of sperm with the glycocalyx of ZP and show whether these oocytes lost the ability to induce the acrosome reaction in sperm. According to our results the oocyte closed vitrification method (S3) does not alter the ability of the sperm binding to the zona pellucida, and their ability to induce the acrosome reaction.

Comparison of three different techniques of human sperm DNA isolation for methylation assay / 华中科技大学学报（医学）（英德文版）

Human sperm DNA is an important genetic and epigenetic material, whose chromatin structure differs from that of somatic cells. As such, conventional methods for DNA extraction of somatic cells may not be suitable for obtaining sperm DNA. In this study, we evaluated and compared three sperm DNA extraction techniques, namely, modified guanidinium thiocyanate method (method A), traditional phenol-chloroform method (method B), and TianGen kit method (method C). Spectrophotometry and agarose gel electrophoresis analyses showed that method A produced DNA with higher quantity and purity than those of methods B and C (P<0.01). PCR results revealed that method A was more reliable in amplifying DEAD-box polypeptide 4 (DDX4) and copy number variations (CNVs) than methods B and C, which generated false-positive errors. The results of sperm DNA methylation assay further indicated that methods A and B were effective, and the former yielded higher quantitative accuracy. In conclusion, the modified guanidinium thiocyanate method provided high quality and reliable results and could be an optimal technique for extracting sperm DNA for methylation assay.

Correlation between hyaluronan binding assay and TUNEL assay for sperm DNA integrity identification.

Objective: To study the correlation between the percentages of HA-unbound sperm and DNA fragmented sperm by TUNEL assay. Methods: The semen residue from semen analysis was tested by HBA and TUNEL assay. Results: The mean age of patients included in the study was 34.8 years (± 3.7 years). The proportion of HA-unbound sperm ranged from 11.3% to 24.2%, with a mean of 17.08% (± 3.24%). The range of TUNEL positive in semen samples was 2% to 11.75%, with a mean of 5.78% (± 2.28%). Pearson’s correlation between two tests was 0.848 (p<0.01). Intraobserver variation of the results of HBA ranged from 3.3% to 7.6%, with a mean of 6.23% (± 1.11%). Intraobserver variation of the results of TUNEL assay ranged from 0% to 6.9%, with a mean of 1.54% (± 2.7%). Agreement measuring of each test was determined by using intraclass correlation. The intraclass correlation coefficient of HBA and TUNEL assay were 0.970 (P<0.001) and 0.997 (P<0.001) respectively. Conclusion: As several studies have found, the binding capacity of sperm to HA is correlated with several sperm parameters. In this study, the strong correlation between the percentages of HA-unbound sperm and TUNEL positive sperm implies, furthermore, that the HA-bound sperm percentage correlates with low levels of DNA fragmentation.

Pharmacological Investigation of Voltage-dependent Ca2+ Channels in Human Ejaculatory Sperm in vitro / 华中科技大学学报（医学）（英德文版）

The types of the voltage-dependent calcium channels (VDCCs) in human ejaculatory sperm and the effects of calcium channel blocker (CCB) on human sperm motility parameters in vitro were investigated. The human sperm motility parameters in vitro in response to the pharmacological agents nifedipine (NIF, inhibitor of L-type VDCC) and ω-conotoxin (GVIA, inhibitor of N-type VDCC) were compared and analyzed statistically. The results showed that NIF (1, 5, 10 μmol/L)could not only significantly affect human sperm's shape but also spermatozoa motility after incubated at least 10 min in vitro (P＜0.001). GVIA (0.1, 0.5 and 1 μmol/L) could just only significantly affect human sperm's progressive motility (a %+b %) after incubated for 20 min in vitro (P＜0.01), but they both could not significantly affect spermic abnormality rate. It is suggested that L-type VDCC, non L-type VDCCs and isoform of L-type VDCC exist in the cell membrane of human sperm solely or together, and they participate in the spermic physiological processes especially the spermic motility.

Effect of Fertilization Promoting Peptide (FPP) on the Acrosome Status of Cryopreserved Human Sperm / 대한불임학회지

No abstract available.

Effect of pentoxifylline on human sperm preparation.

The aim of the research was to study the effects of pentoxifylline on the sperm motility. Thirty samples of semen were studied. Each sample was divided into two sub-samples swim up technique. The other sub-samples were mixed with 3.3 mmol pentoxifylline solution for thirty minutes before entering the process of the sperm swim up preparation. The data regarding sperm concentration, motility, and morphology after 5 minutes of the swim up were recorded. The study showed that the samples that were mixed with 3.3 mmol pentoxifylline had a significantly higher sperm concentration (p< 0.001), greater sperm motility (p = 0.014), and a more normal sperm morphology (p < 0.001) than those samples prepared using the conventional method. It was concluded that pentoxifylline added in the process of sperm preparation could improve the sperm quality outcome.

EFFECTS ON SPERM OOCYTE PENETRATING BY ANTI SERUM TO HUMAN SPERM MANNOSE RECEPTOR / 解剖学报

Objective To study the effect of mannose receptor(MR) from human spermatozoa on sperm-egg fusion. Methods The Balb/c mouse was immunized with the purified mannose receptor(pMR) which was isolated from motile human sperm by mannose-agarose gel affinity chromatography and the anti-MR serum was harvested. Human sperm after induction of acrosome reaction was pretreated with anti-MR serum and subsequently processed in sperm penetration assay (SPA). Results The anti-MR serum can inhibit human spermatozoa from binding and penetrating zona-free golden hamster eggs with a dose-dependent reduction of Fertilization rate(FR) and Penetration index(PI).Conclusion The results indicate that MR of human sperm plays an important role in sperm-oocyte fusion.

Comparison of Intracytoplasmic Sperm Injection and Partial Zona Dissection followed by Insemination in Hamster Oocytes / 대한불임학회지

OBJECTIVES: This study was to investigate the fertilization rate after intracytoplasmic sperm injection (ICSI) or partial zona dissection (PZD) of human and hamster sperm into hamster oocyte in in vitro fertilization (IVF). In addition, the possibility of clinical application was evaluated by the comparison of usefulness and difference of these method. MATERIALS AND METHODS: Hamster immature oocytes were obtained from oviducts superovulated by PMSG and hCG, and hamster sperms were obtained from epididymis. The freezed human sperms were thawed before use. Fertilization were confirmed by two pronuclei, one pronucleus, swollen sperm head or/and two polar bodies at 7~8 hour after ICSI or PZD. RESULTS: The fertilization rates after ICSI and PZD of human sperm to hamster oocyte were 3.6%, 64.2%, 73.6%, and 55.6% for negative control, positive control, ICSI, and PZD respectively, suggesting that ICSI only showed improved fertilization rate (p<0.01). The fertilization rates after ICSI and PZD of hamster sperm to hamster oocyte were 11.1%, 51.2%, 39.6%, and 72.7% for negative control, positive control, ICSI, and PZD respectively, suggesting that PZD only showed improved fertilization rate (p<0.01). PZD showed significantly higher fertilization rate than ICSI (p<0.05). CONCLUSIONS: As for the fertilization rate by ICSI and PZD using hamster oocyte in IVF, ICSI technique was considered to be more useful for human sperm and PZD technique for hamster sperm. Therefore, ICSI technique was considered more appropriate for experimental application using human sperm and hamster oocyte.

The Effect of Temperature and Electrical Energy on Sperm Motility / 대한비뇨기과학회지

Electrical ejaculation is widely used for semen collection in ejaculation failure patients with various causes including spinal cord injury. Semen collected by this method show sperm with low quality, and decrease in sperm motility is especially evident; multifactors are responsible but there are some reports that electrical current and increased temperature during electrical ejaculation are the cause. To confirm this theories, we observed the direct effect of variable electrical current and temperature to the motility of normal sperm in vitro. Semen analysis was performed after temperature was maintained at 37, 39, 41, and 43 `C for 10 minutes and electrical current at 5, 10, 15, 20 Volts for 3, 7, and 10 minutes. 1. Sperm motility change with temperature: The ratio of motile sperm decreased significantly (n=32, p<0.01) from 82.20, 70.12, 60.93, 48.87% as the temperature rose 37, 39, 41, 43 `C, respectively. Factors related to motility (distribution of progressive form and rapid velocity) decreased as well and the distribution of static velocity increased. However, additional semen analysis 20 minutes after rests were not significantly different in sperm motility before and after any temperature changes. 2. Sperm change with electrical energy: The motility of the sperm decreased significantly according to increasing volts and time, which showed a time-dependent and voltage-dependent decrease. The ratio of motile sperm decreased significantly to increasing volts and time and factors related to motility (distribution of progressive form and rapid velocity) also decreased. The distribution of static velocity increased. However, additional semen analysis 20 minutes after rests were not significantly different in sperm motility before and after inducing electrical energies. These data suggest that the effect of electrical current and temperature to sperm motility is temporary and that the low quality of sperm collected by electrical ejaculation in patients with ejaculation failure may not be due to the effect of electrical ejaculation but the various conditions of the patients themselves.