BR RB RATIO OBTAINED BY XRF ANALYSIS OF KIDNEYS OF NORMAL AND TUMOR-BEARING MICE TREATED WITH CIS-DDP/

The Br/Rb ratio in kidneys of normal and tumor-bearing mice was studie d and a significant difference was found between the two groups. The m ice were treated with cis-DDP with and without selenite, with selenite alone, and compared with controls. The animals were sacrificed 7d, 14 d, and 21-28d after treatment. The kidneys were removed and subjected to Br and Rb determination by a novel X-ray fluorescence (XRF) method. The results are presented in terms of estimated net count rates under the BrK alpha and RbK alpha peaks. No significant differences were fo und in Br and Rb levels or in the Br/Rb ratio in kidneys of treated an d untreated mice belonging to the same group - normals or lung carcino ma inoculated. However, there was a significant difference in the Br/R b ratio between the two tested groups (normal and inoculated). Prelimi nary results on the Br/Rb ratio obtained from normal and malignant tis sues of colorectal cancer (CRC) patients and from mice inoculated with melanoma show the same trend as those from the group of mice with lun g carcinoma. In all three groups tested the Br/Rb ratio was 2-4 times higher in normal than in malignant tissue.