[Role of specific iodothyronine-binding proteins in the process of nuclear-cytoplasmic thyroid hormone interrelationships in liver cells].

A study was made of the role played by specific iodinethyrodine-binding proteins of rat hepatocytes in the process of nucleo-cytoplasmic interrelations of the thyroid hormones under normal conditions in thyroidectomy and in experimental thyrotoxicosis. The concentration of the hormone-binding sites in the cell depended on the thyroid hormone level outside the cell. An important role of the cytosol hormone-binding proteins in the accumulation and interacellular distribution of the thyroid cell hormones is emphasized. The absence of any participation of cytosol triiodine-thyronine binding proteins in the process ofpenetration of the hormone into the nucleus was revealed. Triiodine-thyronine level in the nuclei depended directly on the concentration of the recptor proteins in them and the degree of occupation of the acceptor sites in the receptors proper.