Sur la fixation de l'iode ( 131I) par la moule ( Mytilus galloprovincialis L.) et la nature des combinaisons iodees elaborees

Abstract

1. 1. The concentration of 131I by the Mussel ( Mytilus galloprovincialis L.) has been studied, in order to establish if it is connected with the formation of ionated scleroproteins or, as admitted by some authors, with the biosynthesis of thyroid hormones (iodothyronins). 2. 2. Mussels immersed in sea water containing tracer doses of 131INa concentrate iodides actively; this process is reversibly inhibited by sodium thiocyanate and by thiourea as in the thyroid gland of Vertebrates. 3. 3. Radioautography and radioactivity measurements show that 131I is chiefly located in byssus and in periostracum. Fibrous scleroproteins of both bind iodine from sea water very rapidly. 4. 4. Radiochromatographic analysis of hydrolysates of soft tissues, of byssus and of periostracum have shown that 3-monoiodotyrosine and 3,5-diiodotyrosine are the only iodinated organic compounds present. 5. 5. Statements concerning presence of thyroid hormones cannot be confirmed; they can be explained by chromatographic artefacts, also found in our work. 6. 6. Mytilus galloprovincialis L. metabolizes iodine only to integrate it into scleroproteins, similar to gorgonins and antipathins of Anthozoa and to spongins of Spongiara. A confirmation of the absence of a thyroidal function in Invertebrates, except in Protochordata, has been thus brought about by our researches.