The results of our studies: data on the effect of exogenous T3 and T4 on rat kidney function; changes in T3- and T4-depositing function of erythrocytes depending on pH; differences in the dynamics of thyroid status parameters in donors and hyperthyroid patients exposed to ultraviolet irradiation indicate the relevance of the analysis of integration mechanisms of extranuclear parts of thyroid status control into a unified system capable of self-regulation. From these points of view, the study of renal response to exogenous iodothyronines deserves special attention, because, besides metabolic clearance of hypothalamic-pituitary-thyroid axis hormones and inorganic iodine excretion, kidneys may be involved in more complex tasks: filling the red cell depot with triiodothyronine, regulation of thyroxine conversion rate and more profound destruction of thyroid hormones.