THE PECULIARITIES OF ARGINASE PATHWAY OF L-ARGININE IN SPERMATOZOA IN MEN WITH DIFFERENT FORMS OF PATHOSPERMIA.

The changes in arginase activity of spermatozoa and hormonal profile of peripheral blood of infertile men with various forms pathospermia have been studied. It has been found that arginase activity in the sperm cells of men with oligozoo-, antenozoo-, oligoastenozoo- and leucocytospermia is decreased in 2.1, 2.3, 2.4 and 3.3 times respectively. This indicates about inhibition of arginase pathway of L-arginine metabolism, which is not significantly dependent on the type of disruption of spermatogenesis. The most significant changes have been observed in infertile men with leucocytospermia since white blood cells stimulate the formation of reactive oxygen species, induction and development of oxidative and nitrative stress in spermatozoa. Inhibition of arginase pathway of L-arginine metabolism has adaptive role, which is to limit bioavailabil- ity of L-arginine and to prevent excessive formation of NO in cytotoxic concentrations to sperm cells. It has been noted changes in serum concentrations of gonadotropin and sex hormones in men with various forms of pathospermia. The most expressed significant changes were in levels of follicle stimulating hormone and testosterone. The concentration of follicle stimulating hormone in patients with oligozoospermia caused by hypogonadism is twice higher and in patients with leucocytospermia in 1.8 times higher than in fertile men. In patients with astenozoospermia this value is in 2.2 times lower than in normozoospermic samples but within the physiological norm. The testosterone level in men with oligozoospermia is in 1.6 times lower than in fertile men but within the physiological norm. It has been found that arginase inhibition of spermatozoa po6itively correlated with a decrease in their concentration in the ejaculate of infertile men with oligozoospermia (r =0.68).

[Arginase and NO-synthase pathways of L-arginine metabolism in peripheral blood lymphocytes of patients with ovarian cancer].

The peculiarities ofarginase and NO-synthase pathways of L-arginine metabolism in peripheral blood lymphocytes of patients with ovarian cancer were studied. It was shown that the development of cancer pathology is associated with an imbalance in the NO synthesis in blood lymphocytes. The reason for such imbalance is the activation of arginase and inducible isoform of NO-synthase (iNOS) and significant inhibition of its constitutive isoform. The analysis of the kinetic properties of NOS of blood lymphocytes of patients with ovarian cancer was carried out. It was shown that the affinity constant of iNOS affinity for L-arginine is 5.4-fold lower than for eNOS of blood lymphocytes of persons in the control group. The inhibition of eNOS occurs via non-competitive type and is related to the reduction of maximum reaction rate.

[Kinetic properties of Na+, K+ activated, Mg2+ -dependent ATP-hydrolysis of blood lymphocytes in patients with rheumatoid arthritis and ankylosing spondyloarthritis].

The comparative analysis of the kinetic properties of ouabain-sensitive Na+, K+ -ATPase activity of saponin-perforated blood lymphocytes of donors and patients with rheumatoid arthritis (RA) and ankylosing spondyloarthritis (AS) was carried out. When analyzing the alterations in hydrolase activity of the examined enzyme it was shown that in the blood lymphocytes of patients with RA and AS the primary active transport of Na+ and K+ ions is less intensive in comparison with practically healthy donors, but it is characterized by almost the same capacity as in donors. The affinity constant of Na+, K+ -ATPase for ATP in the blood lymphocytes in patients with RA and AS is greater 3.1 and 2.5 times, respectively, in comparison with healthy donor. It was found that in conditions of rheumatic pathology in immunocompetent cells the inhibition of Na+, K+ -ATPase activity is not related to the reduction of maximum reaction rate, but is related to the decrease of Na+, K+ -ATPase affinity to ATP. However, Mg2+ -binding center of Na+, K+ -ATPase in patients with RA and AS remains native. It was identified that the affinity constant of Na+, K+ -ATPase to Na+ ions in the blood lymphocytes of patients with RA and AS is 2.75 times lower than its value in healthy donors. Na+, K+ -ATPase of the blood lymphocytes of patients with RA and AS retains its native receptor properties and sensitivity to ouabain does not change.

[Characteristics of Ca2+, Mg(2+)-ATPases of peripheral blood lymphocytes of patients with rheumatic pathology].

The analysis of the kinetic properties of Ca2+, Mg(2+)-ATPase of saponin-perforated peripheral blood lymphocytes of donors and patients with rheumatoid arthritis and ankylosing spondylitis was carried out. When analyzing the alterations in hydrolase activity of Ca2+, Mg(2+)-ATPase it was shown that affinity of Ca2+, Mg(2+)-ATPase of plasma membrane and membranes of endoplasmic reticulum for ATP do not significantly differ. It was found that the inhibition of examined enzyme systems occurs by mixed type both due to the reduction of maximum reaction rate and to the decrease of Ca2+, Mg(2+)-ATPase affinity for ATP in conditions of rheumatic pathology in the immunocompetent cells. It was identified that Ca2+, Mg(2+)-ATPase had significantly lower affinity for Ca2+ in lymphocytes of persons with rheumatic disorders than in donors.

[Identification of Ca(2+)-activated Mg(2+)-dependent ATP-hydrolase activity of membrane microsomal fraction of loach embryo (Misgurnus fossilis L.)].

The functional confirmation of availability of Ca2+ transport initially-active systems in the embryo cells of loach Misgurnus fossilis L. has been obtained. Using thapsigargin, the specific inhibitor of endoplasmic reticulum of Ca2+, Mg(2+)-ATPase, this enzyme activity was divided into thapsigargin-sensitive (actually endoplasmic reticulum Ca2+, Mg(2+)-ATPase) and thapsigargin-insensitive (plasma membrane Ca2+, Mg(2+)-ATPase) constituents. The Ca(2+)-independent Mg(2+)-dependent ATPase activity makes above 39.7% of the common Ca2+, Mg(2+)-ATPase activity of embryo loach. The periodic changes of Ca2+, Mg(2+)-ATPase activity (except for the changes of plasma membrane Ca2+, Mg(2+)-ATPase activity) were found out, which coincide with periodic [Ca2+]i oscillations during the synchronous divisions of loach blastomers embryos.