ACTIVITY AND IMMUNOHISTOCHEMISTRY OF DT-DIAPHORASE IN HAMSTER AND HUMAN KIDNEY TUMORS

We have studied the biochemical and immunohistochemical changes of DT- diaphorase in diethylstilbestrol (DES)-induced hamster kidney tumours and human biopsies from normal kidneys and renal clear cell carcinoma. The activities of primary and secondary antioxidants in these hamster and human tissues are also reported. DT-diaphorase is decreased in th e different subcellular fractions of hamster and human tissues. In ham ster kidney the activities of the one-electron quinone reductases show a nearly two-fold increase. Immunohistochemical findings confirm the decrease in DT-diaphorase in hamster and human tissues. This image is of special interest in the case of nephroblastoma (Wilms' tumour), sin ce it has been proposed that the DES-induced tumour is a 'nephroblasto ma-like' one. Primary anti oxidant enzymatic activities, i.e. superoxi de dismutase and glutathione peroxidase, are increased in hamster kidn ey bearing DES-induced tumours and decreased in human renal clear cell carcinoma. Glutathione disulphide reductase is decreased in hamster a nd human tumours. The role of these enzymatic activities in the carcin ogenic process is also discussed.