Effect of various factors on ejaculate fertility in vitro

Abstract

Introduction. Current demographic situation in Russia is characterized by decreasing birth rate. According to the World Health Organization, percentage of child-free marriages in various countries is 10–15 %. In Russia, the National Medical Research Center for Obstetrics, Gynecology, and Perinatology named after Academician V.I. Kulakov states that this number is 17 %. More than 4 million men suffer from infertility of various types. In recent years, pathologies of male reproductive function have achieved medical and social significance due to progressively decreasing sperm fertility. Fertility disorders are considered multi-factor conditions caused by internal and external factors and leading to pathological changes in sex organs. Correction of pathologies of male fertility does not always lead to positive results. Therefore, it is important to develop and study effective pharmaceuticals affecting the main fertility parameters.The study objective is to investigate the effect of various biological pharmaceuticals, physical and chemical factors on parameters of ejaculate fertility in vitro.Materials and methods. Experiments with a protein-peptide complex (PPC), methylene blue, and hydrogen peroxide were performed on human semen. After semen dilution, the sample was studied under the microscope and sperm motility and other ejaculate parameters were evaluated per the 5th edition WHO standard. Experiments were performed at 20–22 ºС. Statistical data analysis was performed using the Student’s t-test. Differences were considered statistically significant at р <0.05.Results. The results show increased motility in the fraction of active motile sperm in first 30 minutes after incubation with methylene blue. In case of initial asthenospermia, active motility increased by 72 %, in case of normospermia by 89 %. After 2 hours, all motility fractions were at the baseline level.The experiments also showed significant changes in sperm motility in the presence of PPC preparation in the ejaculate: increase in sperm motility was observed beginning at 30-minute mark and this level persisted through 3 hours of observation. A more pronounced change, by 60 %, was observed in the active motile sperm; total motility increased by up to 30 %. After 24 hours, sperm motility remained close to the baseline level, the number of normal sperm forms and live cells did not change. Dependence of the motility change on the preparation concentration should be noted: the highest increase was observed at PPC concentration with total protein level of 10–12 mg/mL. Higher concentrations did not have a positive effect on sperm motility. In experiments with low hydrogen peroxide concentration, a positive effect on sperm motility was observed.Conclusions. Sperm motility is supported by glycolysis energy, and one of the glycolysis enzymes glyceraldehyde 3-phosphate dehydrogenase is tightly bound to the fibrous layer of the flagellum, activation of metabolic pathways leading to increased enzyme activity, increased sperm motility. The mechanism of the observed effect is not entirely clear, however, the obtained data demonstrate potential benefits of further studies on use of pharmaceuticals in andrological and reproductive practice, assisted reproductive technologies, as well as for stimulation of sperm motility in further experimental studies.