[Effect of malignant tumors with various characteristics on the state of the estradiol receptor system in peripheral target organs].

Experiments on 24 randombred rats with growing lymphosarcoma and mammary carcinoma have demonstrated alterations in steroid-producing function of the ovaries and adrenals and in the estradiol-receptor system. These alterations were found to be inconclusive and dependent on the characteristics of the growing tumor. In rats bearing lymphosarcoma, the reduced estradiol levels in the blood and ovaries were in agreement with a negligible number of cytoplasmic and nuclear receptors in the uterus, mammary glands and tumor. Rats with mammary carcinoma demonstrated an increase in estradiol levels in the blood, ovaries and adrenals and a dramatic fall in the blood progesterone level. In this case the number of cytoplasmic receptors in the uterus and mammary glands decreased, whereas that in the nucleus dramatically rose. The measurement of the number of estradiol molecules in the nucleus and cytoplasm and its correlation to the receptor number made it possible to reveal substantial differences between the estradiol-receptor systems in the two tumors regardless of the low level of receptors in both tumors.