RESUMEN
AIM: To study the relationship between the level of generation of reactive oxygen species (ROS) and nitric oxide (NO) and activity of matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in the vessels isolated from rectal tumors and Arteria rectalis superior. METHODS: EPR at the room temperature and 77 degrees K, Spin Traps technology and zymography in polyacrylamide gels were applied. RESULTS: In the vessels isolated from rectal tumors and Arteria rectalis superior high levels of ROS, NO and formation of complexes of NO with FeS-proteins at the sites of electron-transporting chain of mitochondria have been detected. High activities of MMP-2 and MMP-9 in vascular wall were also observed. The direct positive correlation between the rate of NO generation and formation of complexes of NO with FeS-proteins as well as between ROS and NO formation and MMPs activities have been revealed. CONCLUSION: Altered oxidative equilibrium in mitochondria of cells in vascular wall promotes formation of cell hypoxia and its autocatalytic potentiation accompanied with activation of MMPs.