PROPERTIES OF CA2+-DEPENDENT AND CA2+-INDEPENDENT ISOFORMS OF NO-SYNTHASE IN BLOOD LYMPHOCYTES OF OVARIAN CANCER WOMEN

The purpose of the present work was to study the enzyme activity and kinetic properties of NO-synthase in blood lymphocytes of women with ovarian cancer. Studies were conducted on the blood lymphocytes of women with ovarian cancer of the II-.V degrees (n=26) and healthy women (n=24, control group). It has been found that constitutive isoform of NO-synthase of blood lymphocytes of women with ovarian cancer was 4.0 fold lower compared to control group. The activity of inducible NOsynthase in blood lymphocytes of practically healthy women was (1.52 +/- 0.46) nmol NADPH(H+)/min.mg of protein and in women with ovarian cancer it increased in 144 times. The maximum rate of constitutive isoform of NO-synthase reaction in patients with ovarian cancer was reduced 5 fold and for inducible NO-synthase reaction was increased in tens of times compared to control group. For oncopathology the imaginary affinity constant to arginine for inducible NO-synthase was in 5.4 times lower compared to inducible NO-synthase of control group. The inhibition of constitutive isoform of NO-synthase occurs by competitive type - by reducing the rate of enzyme reaction.