Human biochemical genetics / by H. Harris.

  • Harris, Harry, 1919-1994.
Date:
1966
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Human biochemical genetics / by H. Harris. Source: Wellcome Collection.

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    б2 aminoacid metabolism: i effect by inhibiting the transfer of iodide to tyrosyl residues by blocking in some way the enzymically controlled oxidation of iodide to iodine. It seems likely that this is the point at which iodide metabolism is blocked in the thyroid glands of this group of goitrous cretins. Direct analysis of thyroid gland material from these patients failed to reveal any iodinated compounds, though these could readily be demonstrated in normal or hyperplastic glands using the same Time in hours Fig. 13. Uptake of radioactive iodine by the thyroid in a goitrous cretin and his normal sib. At zero time a tracer dose of 100 microcuries of radioactive iodine was given by mouth. Potassium thiocyanate was administered a day later. (After Stanbury and Hedge (67)). method. Thus the glands may contain iodide and even show excessive avidity for iodide but no incorporation into the organic form occurs. In effect there appears to be a complete block in hormone formation at a very early stage, and the large goitres and intense cellular hyper¬ trophy and hyperplasia can be regarded as compensatory phenomena. Other types of defect It seems likely that several other types of condition also exist, each of which is probably genetically distinct and represents a failure at some specific point in normal thyroid metaboHsm. For example, Stanbury, Ohela and Pitt-Rivers (68) have described a condition in two sisters where the essential defect appeared to be a failure in the ability