Study of the immunoglobulin and oxidized protein content of semen under infertility

Abstract

Among the causes of male infertility, enough attention is paid to oxidative stress, which in turn is a pathogenetic link in the inflammatory process. However, there is practically no information on the content of oxidized modified proteins in the semen, which makes it difficult to study the pathogenesis of diseases of the male reproductive system. In part, protein oxidation may be due to the production of reactive oxygen species by microorganisms, both directly and indirectly through the activation of immune system cells. The aim of the research was to study the level of oxidized modified proteins and changes in immunoglobulin concentrations in the semen under bacteriospermia. A study was made of the ejaculate of 48 men who applied to the clinic for infertility in marriage. The comparison group consisted of 32 practically healthy men who had no growth of microorganisms in the ejaculate samples. When conducting bacteriological analysis, the studied samples were diluted 10 times and used the generally accepted method. The concentration of albumin, immunoglobulins A, M, G, E was determined in the spermatic fluid. The oxidative modification of proteins was evaluated in the reaction with 2,4-dinitrophenylhydrazine. The concentration of oxidized proteins was expressed in nmol/mg of the total protein of the studied biological fluid. The biuret method was used to determine the protein concentration. Statistical analysis of the results was performed using descriptive statistics and Student's t-test for paired data. The concentration of protein in the seminal fluid did not differ significantly among the studied groups. The albumin concentration (16.96±1.28 mg/mL) was statistically significantly lower in the absence of microorganism growth than in bacteriospermia. With bacteriospermia, a decrease in the concentration of IgM and IgA and an increase in the level of IgG were noted. The degree of protein oxidation is maximum when enterobacteria are isolated from seminal fluid. Thus, during the studies it was found that, despite the absence of a clinic, with asymptomatic bacteriospermia, the secretion of immunoglobulins G into the semen is observed. The accumulation of oxidized proteins in the seminal fluid in bacteriospermia has been shown.

Keywords

• oxidized proteins
• semen
• dinitrophenylhydrazine
• aldehyde derivatives
• ketone derivatives
• immunoglobulins