EFFECTS OF A NITRIC OXIDE DONOR, THE SUBSTRATUM OF NO-SYNTHASE,
AND AN INHIBITOR OF NO-SYNTHASE ON THE ROS-GENERATION ACTIVITY
OF PHAGOCYTES IN THE COURSE OF ASCITES TUMOR GROWTH
A. A. Naumov, M. M. Potselueva 1
Institute of Theoretical and Experimental Biophysics RAS,
Pushchino, Moscow Region, and Pushchino State University;
1 e-mail: mpotselueva@rambler.ru
Experiments in vitro were performed to investigate the effects of the nitric oxide donor (SNP), the substratum
of NO-synthase (L-arginine), and the inhibitor of NO-synthase (nitroarginine) on the ROS-generating activity
of blood plasma polymorphonuclear leucocytes and ascitic fluid macrophages isolated at different times oftumor
(Zaidel hepatoma) growth in animal organism. It was found that in the initial period of tumor growth the
nitric oxide donor at a concentration of 8·10-5 M reduced the potential ROS-generating activity of macrophages
by 38.5 ± 9.0 % and that of polymorphic-nuclear leucocytes of plasma by 27.6 ± 7.0%. However, the dynamics
of this process during tumor growth was conservative: variations in the production of ROS by phagocytes were
10 ± 3.0%. L-arginine induced a decrease in the ROS-generating activity of granulocytes and mononucleares
by 25-30%. This fact points to an inducible inhibiting effect of NO-synthase on the ROS-generating activity
of NADPH-oxidase in the course of tumor growth. The inhibitor of NO-synthase, nitroarginine, produced a monotonous
increase in the ROS-generating activity of phagocytes isolated from the tumor at different periods of
its growth. The use NO-synthase inhibitors for increasing ROS levels in the region of tumor growth may favor
the suppression of tumor cell growth in vivo.
Key words: luminescence, ROS-generating activity, NO-synthase, polymorphonuclear leucocytes, tumor growth
| Pdf
| Back
| Contents
| Main |
