EFFECT OF VARIOUS CHEMOSENSITIZERS ON CHEMORESISTANCE TO ADRIAMYCIN IN MIP-101 CELL-LINE, A COLON-CARCINOMA CELL-LINE - ANALYSIS OF GLUTATHIONE AND RELATED ENZYMES

We evaluated the multidrug resistance modulating effect of verapamil, buthionine sulfoximine, trifluoperazine and tamoxifen in a human color ectal cell line resistant de novo to adriamycin. We studied the effect of these chemosensitizers on glutathione content, glutathione reducta se, transferases, peroxidases, gamma-glutamyl transpeptidase and gluco se-6-phosphate dehydrogenase activities. The ratio of the activities b etween resistant and sensitive cells treated by these compounds as com pared with the ratio of the untreated cells decreases, thus contributi ng to the reversal of chemoresistance. This study implies a role of gl utathione and related enzymes in chemoresistance to adriamycin, althou gh this is certainly not the sole mechanism.