Increased peroxidase activity in Pendred's syndrome with hypothyroidism.
An 8-year-old boy with goiter and bilateral nerve deafness had a 46% discharge of radioiodine after thiocyanate administration. He was clinically euthyroid. Although the serum total T4 was low (2.4 mug/100 ml) and TSH was significantly high (181 muU/ml), the serum total T3 was normal (152 ng/100ml). It was considered that the increased release of TSH by the feedback mechanism in response to the low T4 resulted in a quite normal level of serum T3. The thyroid gland demonstrated a low stable iodine content, an increase in MIT/DIT ration and a decrease in iodothyronine. The thyroglobulin behaved normally in Sephadex G-200 chromatography and immunoreaction. Thyroid tissue exhibited increased peroxidase activity as measured by I3 formation. Increased peroxidase activity may be related to the observed increase in serum level of TSH.
D002648:Child; D003638:Deafness / Q000150:complications / Q000201:enzymology* / Q000473:pathology; D006042:Goiter / Q000150:complications / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000201:enzymology* / Q000473:pathology; D008297:Male; D010544:Peroxidases / Q000378:metabolism*; D013577:Syndrome; D013954:Thyroglobulin / Q000502:physiology; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000201:enzymology; D013972:Thyrotropin
D013972:Thyrotropin; D013954:Thyroglobulin; D010544:Peroxidases