Determination of estrogen 3-sulfates in biological fluids of mammary tumor-bearing rats by radioimmunoassay.

Determination of estradiol 3-sulfate (E2 3-S) and estriol 3-sulfate (E3 3-S) in plasma, urine or tumor tissues of mammary tumor-bearing rats were performed using the superior radioimmunoassay (RIA) system. The plasma level of E2 3-S after tumorigenesis was found to be about one-third of the normal level. As to E3 3-S, the levels in urine were significantly high both before and after tumorigenesis. Before that, the average level was about 1.5 times, and after that, about 2.5 times as high as the normal level. In tumor tissues, an extremely high level of E3 3-S (399.6 +/- 113.9 pg/g tissue) was determined.