SUR LES 3:3′:5′-TRIIODOTHYRONINE (T′3) ET 3:3′-DIIODOTHYRONINE (T′2) CONSIDEREES COMME CONSTITUANTS DE L'HORMONE THYROIDIENNE CIRCULANTE

Abstract

Using radiochromatography, 3:3′-diiodothyronine (T′₂) and 3:3′:5′-triiodothyronine (T′₃) have been identified in plasma of rats injected with ¹³¹INa. These compounds are present in very small quantities. l-thyroxine represents in general three quarters of the hormonal iodine just as in the thyroid gland. 3:3′-diiodothyronine and 3:3′:5′-triiodothyronine are secreted into plasma by the gland. However the former, whose formation in the tissues from 3:5:3′-triiodothyronine has been established, can also be partly of peripheral origin and present together with very small quantities of various thyroid hormone metabolites which can accompany them in plasma.