ABSTRACT
To study the endogenous concentration of androgens and oestrogens in target tissue, three different methods have been used: (a) measurement of concentration gradient across mammary tumours, (b) long-term infusion of subphysiological amounts of labelled oestrogens and measurement of tissue-plasma gradients in human uterine tissue and (c) measurement of endogenous concentrations in mammary and uterine tissues. In addition to the tissue-plasma gradient, the subcellular distribution was also measured. An improved method is presented for processing the tissue and for the quantitative extraction of steroid hormones from cytosol and nuclear fraction. The data obtained show clearly that steroid hormones have a tissue-plasma gradient that varies from tissue to tissue and from one hormone to another. As steroid hormones exert their influence intracellularly at the site of receptor binding, our findings may have major consequences for the study of hormone-related cancers of the breast and of the uterus.
