AUTORADIOGRAPHIC DISTRIBUTION STUDIES AFTER ADMINISTRATION OF A MACROMOLECULAR SYNTHETIC OESTROGEN (14C-POLYDIETHYL-STILBOESTROL PHOSPHATE)

Abstract

ABSTRACT The distribution of a macromolecular depot-type stilboestrol compound, polydiethylstilboestrol phosphate labelled with 14C or 3H, has been studied by autoradiography in mice. The blood concentration was high up to four hours after injection but dropped to a scarcely perceptible level after one day. Small foci of radioactivity could be detected in most tissues of the body, particularly tissues containing abundant reticuloendothelial cells such as the liver, spleen, bone marrow and lung. There was also early specific uptake in sites such as the endometrium, the follicular epithelium in large Graafian follicles, corpora lutea, adrenal cortex, and interstitial cells of the testicle – all places in which we have previously observed accumulation of monomolecular diethylstilboestrol. At these sites distribution was uniform. Our results suggest that the reticuloendothelial system serves as a depot for the polymerised polystilboestrol and that monomolecular stilboestrol is slowly released from the depots and then accumulated in the target organs.