Nuclear androgen receptor assay in biopsy-size specimens of human prostatic tissue

Nuclear androgen receptors in benign and malignant human prostatic tumors were estimated with a nuclear exchange assay to evaluate the applicability of the assay to biopsy size tissue samples. The mean nuclear androgen receptor content of six different prostate samples was not dependent on the amount of tissue used. In contrast, however, there was no significant correlation between the results obtained for individual prostates when large samples (500 mg) and samples weighing 100, 50(r = 0.38, n = 14), and 25 mg were compared. This lack of correlation could not be attributed to variations in the assay nor to differences in the percentage of epithelium in the samples. There was no effect of the presence of molybdate on the estimated nuclear androgen receptor level. We concluded that androgen receptors are distributed nonhomogeneously over prostatic tissue and that androgen receptor assays on multiple biopsies are required to obtain a proper estimate of the true androgen receptor content of the tissue.