GLUTATHIONE AND GLUTATHIONE METABOLIZING ENZYMES IN TISSUES AND BLOODOF BREAST-CANCER PATIENTS

Many reports indicate that glutathione and enzymes cooperating with it are important in neoplastic processes. Glutathione (GSH) concentratio ns and glutathione S-transferase (GSH STr) and glutathione peroxidase (GSH-Px) activities were determined in breast cancer tissue and adjace nt healthy tissues, as well as in blood of 28 patients. There were con siderable differences in the investigated parameters among individual patients. Therefore we analyzed the paired samples of normal and cance rous tissues from the same individual. In 68% of the patients the acti vities of GSH-Px and in 85% patients those of GSH STr were found to be higher in the tumor than in the normal tissue. GSH concentration in 4 8% tumor samples were higher and in 44% lower than in corresponding no rmal tissues. Statistically significant correlation was found between GSH-Px and GSH STr in normal (r = 0.51, p < 0.005) and in cancer tissu es (r = 0.64, p = 0.001). Correlation coefficient between GSH Pr activ ity in normal and corresponding cancer tissues was r = 0.71 (p < 0.001 ), however this correlation in the case of GSH STr was much lower but still significant (r = 0.38, p < 0.05). No significant correlation in the determined parameters was found between erythrocytes or plasma and normal or cancer tissues.