• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.143-154
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• 2000

Most eggs initiated the fertilization processes but arrested at specific stages. The stages included failure of the oocyte to exit from the meiotic metaphase-II with or without sperm penetration, failure of appropriate sperm aster formation, inability to form proper male and female pronuclei, failure of suitable pronuclear apposition, and failure to form proper number of either male or female pronuclei. Various images of defective microtubule organization and chromatin configuration during IVF and ICSI procedures were observed. We discussed the data with previous research results during normal fertilization in humans and other mammals. In conclusion, various aberrant patterns in microtubule assembly and chromatin configuration, which were assessed in the present study, could be used as criteria to improve assisted reproductive technology in clinics. However, further cellular and molecular characterization is needed to clarify these aberrant patterns of cytoskeletal assembly.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.2
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• pp.203-210
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• 1995

Many oocytes fail to fertilize and cleave in vitro and many embryos transferred back to uterus fail to implant or maintain implantation. Chromosomal abnormalities in the male and female gametes may contribute to this loss. The higher incidence of meiotic chromosomal abnormalities bas been found in oocytes than in sperm. The wide range of incidence of chromosomal abnormalities in unfertilized oocytes has been reported in human IVF program (26-63%). However, factors affecting chromosomal abnormalities are not well understood. The present study has been conducted to investigate effects of the method for ovarian hyperstimulation, women's age, and the number of oocytes retrieved per patients on the incidence of numerical chromosomal abnormalities. Five hundred eighty four unfertilized metaphase II oocytes were subjected to chromosomal analysis. Included unfertilized oocytes were from 220 patients (mean $age=32.7{\pm}3.0$) and three hundred thirty oocytes were legible for analysis. Two hundred fourty five oocytes out of 330 (73.3%) were normal, while 38 (11.5%) were hyperploidy, 35 (10.6%) were hypoploidy, and 12 (3.6%) were diploidy. Significant difference in chromosomal abnormalities was not found between two patient groups stimulated by follicular stimulating hormone/human menopausal gonadotrophin (FSH/HMG) (25.9%) and gonadotrophin-releasing hormone agonist/follicular stimulating hormone/human menopausal gonadotrophin (GnRHa/FSH/HMG) (28%). There was a tendency of increasing chromosomal abnormalities in unfertilized oocytes from older patients (<30 yrs: 20.3%, 30-34yrs: 26.9%, >34 yrs: 35.3%). The number of oocytes retrieved per patient had no effect the incidence of chromosomal abnormalities (1-5: 31. 4%, 6-10: 29.8%, 11-15: 28.6%, > 15: 16.5%). These results from the present study suggest that the chromosomal abnormalities observed in the unfertilized oocytes has not affected by the stimulation methods, patient's age, and the number of oocytes retrieved per patients.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.2
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• pp.97-101
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• 2016

Objective: Growth hormone and its mediator, insulin-like growth factor-1 (IGF-1), have been suggested to exert gonadotropic actions in both humans and animals. The present study was conducted to assess the relationship between serum IGF-1 concentration, seminal plasma concentration, and sperm parameter abnormalities. Methods: A total of 79 men were enrolled in this study from December 2011 to July 2012 and were prospectively analyzed. Patient parameters analyzed included age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal (A, n=31), abnormal sperm motility (B, n=12), abnormal sperm morphology (C, n=20), and two or more abnormal parameters (D, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined. Results: Patient baseline characteristics were not significantly different between any of the groups. The serum IGF-1 levels in groups B, C, and D were significantly lower than the levels in group A; however, the seminal plasma IGF-1 levels were not significantly different between any of the groups. Conclusion: Men with abnormal sperm parameters had significantly lower levels of serum IGF-1 compared with men with normal sperm parameters. Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.4
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• pp.277-284
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• 2022

Objective: Oxidative stress is a key player in the development of idiopathic male infertility (IMI), and various antioxidants have been used for the treatment of IMI with inconsistent results. Coenzyme Q10 (CoQ10) is a cofactor and an antioxidant that may improve semen parameters and reduce oxidative stress in patients with idiopathic oligoasthenospermia (OA). Therefore, this study aimed to explore the effect of CoQ10 on semen parameters and antioxidant markers in patients with idiopathic OA. Methods: Fifty patients with idiopathic OA and 35 fertile controls were enrolled in this prospective controlled study. All participants underwent a comprehensive fertility assessment. All patients received CoQ10 (300 mg/day) orally once daily for 3 months. Semen parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured in patients and controls at the start of the study and after 3 months. Results: Treatment with CoQ10 resulted in increased sperm progressive motility (p<0.05), total motility (p<0.01), seminal TAC (p<0.01), SOD (p<0.05), GPx (p<0.001), and seminal CoQ10 (p<0.001) levels and reduced ROS (p<0.01) in patients as compared to baseline. Sperm concentration and motility were also significantly correlated with antioxidant measures and seminal CoQ10 levels (r=0.38-0.57). Conclusion: CoQ10 therapy (300 mg/day for 3 months) improved sperm motility and seminal antioxidant markers in patients with idiopathic OA. Therefore, CoQ10 could be a promising treatment for patients with idiopathic infertility and may improve their fertility potential.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.150-155
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• 2021

Objective: Oxidative stress (OS) plays a key role in the etiology of unexplained male infertility. Coenzyme Q10 (CoQ10) is a potent antioxidant that may improve semen quality and OS in infertile men with idiopathic oligoasthenoteratospermia (OAT), but the underlying mechanism is unknown. Therefore, the present study was undertaken to investigate the effect of CoQ10 on OS markers and sperm DNA damage in infertile patients with idiopathic OAT. Methods: This prospective controlled study included 50 patients with idiopathic OAT and 50 fertile men who served as controls. All patients underwent a comprehensive medical assessment. Patients and controls received 200 mg of oral CoQ10 once daily for 3 months. Semen and blood were collected and analyzed for sperm parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity, catalase, sperm DNA fragmentation (SDF), and serum hormonal profile. Results: The administration of CoQ10 to patients with idiopathic OAT significantly improved sperm quality and seminal antioxidant status and significantly reduced total ROS and SDF levels compared to pretreatment values. Conclusion: CoQ10, at a dose of 200 mg/day for 3 months, may be a potential therapy for infertile patients with idiopathic OAT, as it improved sperm parameters and reduced OS and SDF in these patients.

• Animal Bioscience
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• v.36 no.3
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• pp.385-403
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• 2023

Male fertility is affected by multiple endogenous stressors, including reactive oxygen species (ROS), which greatly deteriorate the fertility. However, physiological levels of ROS are required by sperm for the proper accomplishment of different cellular functions including proliferation, maturation, capacitation, acrosomal reaction, and fertilization. Excessive ROS production creates an imbalance between ROS production and neutralization resulting in oxidative stress (OS). OS causes male infertility by impairing sperm functions including reduced motility, deoxyribonucleic acid damage, morphological defects, and enhanced apoptosis. Several in-vivo and in-vitro studies have reported improvement in quality-related parameters of sperm following the use of different natural and synthetic antioxidants. In this review, we focus on the causes of OS, ROS production sources, mechanisms responsible for sperm damage, and the role of antioxidants in preserving sperm fertility.

• Reproductive and Developmental Biology
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• v.33 no.1
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• pp.55-61
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• 2009

The epididymis in the male reproductive tract is the site where spermatozoa produced from the testis become mature. The epididymis is divided into 4 different segments, initial segment and caput, corpus, and caudal epididymis, depending upon functional and morphological features. Aquaporins (Aqps) are water channel molecules, which are present in the epididymis and play a major role in removal of epididymal water, resulting in creation of microenvironment for sperm maturation and concentration of sperms. Nandrolone decanoate (ND) is a synthetic anabolic-androgenic steroid, which is used to treat clinical diseases and improve physical ability and appearance. Even though it is well determined that the ND causes the male infertility by affecting the testis, little is known the effect of the ND on the epididymis. The present study was focused to examine the effect of ND at different treatment doses and periods on expression of Aqp1 and Aqp9 genes in the epididymis of pubertal rats. Results showed that mRNA expression of Aqp1 and Aqp9 genes among the parts of the epididymis was differentially regulated by ND treatment doses. In addition, treatment periods of ND caused differential expression of Aqp1 and Aqp9 mRNAs among segments of the epididymis. Therefore, it is believed that male infertility induced by ND could be resulted not only from malfunction of the testis but also from aberrant gene expression of Aqp1 and Aqp9 in the epididymis.

• Clinical and Experimental Reproductive Medicine
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• v.45 no.2
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• pp.88-93
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• 2018

Objective: The aim of this study was to measure reactive oxygen species (ROS) production and total antioxidant capacity (TAC) in the seminal fluid of the male partners in couples undergoing intrauterine insemination and to evaluate correlations between these values and their semen parameters. Methods: The study was conducted at Vamsam Fertility Center, Coimbatore, India and enrolled 110 male patients from whom semen samples were collected. ROS production was measured by a thiobarbituric acid reactive species assay, and TAC was measured by a 2,2-diphenyl-2-picrylhydrazyl free radical assay. The differences in the TAC and malondialdehyde (MDA) levels between the subfertile and fertile groups were analysed. Correlations between sperm parameters and TAC and MDA levels were statistically analysed, and cutoff values with respect to the controls were determined. All hypothesis tests used were two-tailed, with statistical significance assessed at the level of p< 0.05. Results: A total of 87 subfertile and 23 fertile men were included in the study. The mean MDA level was significantly higher in the subfertile subjects than in the fertile subjects, and the mean antioxidant level was significantly lower in the subfertile subjects than in the fertile subjects. Seminal MDA levels were negatively associated with sperm concentration, motility, and morphology, whereas the opposite was seen with TAC levels. Conclusion: Measurements of seminal TAC and ROS are valuable for predicting semen quality, and hence predicting the outcomes of fertility treatment.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.3
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• pp.77-85
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• 2015

One of the key factors of early development is the specification of competence between the oocyte and the sperm, which occurs during gametogenesis. However, the starting point, growth, and maturation for acquiring competence during spermatogenesis and oogenesis in mammals are very different. Spermatogenesis includes spermiogenesis, but such a metamorphosis is not observed during oogenesis. Glycosylation, a ubiquitous modification, is a preliminary requisite for distribution of the structural and functional components of spermatids for metamorphosis. In addition, glycosylation using epididymal or female genital secretory glycans is an important process for the sperm maturation, the acquisition of the potential for fertilization, and the acceleration of early embryo development. However, nonemzymatic unexpected covalent bonding of a carbohydrate and malglycosylation can result in falling fertility rates as shown in the diabetic male. So far, glycosylation during spermatogenesis and the dynamics of the plasma membrane in the process of capacitation and fertilization have been evaluated, and a powerful role of glycosylation in spermatogenesis and early development is also suggested by structural bioinformatics, functional genomics, and functional proteomics. Further understanding of glycosylation is needed to provide a better understanding of fertilization and embryo development and for the development of new diagnostic and therapeutic tools for infertility.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.101-109
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• 2022

Objective: Y chromosome microdeletions are the second most common genetic cause of male infertility after Klinefelter syndrome. The aim of this study was to determine the patterns of Y chromosome microdeletions among infertile Mongolian men. Methods: A descriptive study was performed on 75 infertile men from February 2017 to December 2018. Y chromosome microdeletions were identified by polymerase chain reaction. Semen parameters, hormonal levels, and testis biopsy samples were examined. Results: Among 75 infertile men, two cases of Y chromosome microdeletions were identified. The first case had an AZFa complete deletion and the other had an AZFc partial deletion. This study found that the proportion of Y chromosome microdeletions among infertile Mongolian men was 2.66%. Conclusion: The findings can be applied to in vitro fertilization and assisted reproductive technology, and our results will help clinicians improve treatment management for infertile Mongolian couples.