5'-Monodeiodinase activity in developing human cerebral cortex.
Iodine status of aborted fetuses (11-25 wk gestation) was determined on the basis of maternal thyroid status and urinary iodine excretion. Fetal cerebral cortex thyroxin and 3,5,3'-triiodothyronine (T3) contents peaked at 15-18 wk gestation and then fell in iodine sufficiency. In mild iodine deficiency T3 concentration was maintained at a higher level until week 22, although it were still significantly less than in the iodine-sufficient group. Reverse T3 (rT3) rose from 11 to 22 wk gestation without any effect of iodine status. The activity of 5' and 5-monodeiodinase also increased from 11 to 22 wk gestation, with 5' monodeiodinase activity significantly increased by mild and moderate iodine deficiency. In contrast, cerebral cortex 5-monodeiodinase activity was significantly lower in moderate iodine deficiency at 15-18 wk gestation. The observations indicate that cerebral cortex 5' and 5 monodeiodinase activities are modulated in iodine deficiency to enhance T3 production from thyroxin (T4) during the period that coincides with neuroblastogenesis.
Karmarkar
M G
MG
Department of Endocrinology and Metabolism, All India Institute of Medical Sciences, New Delhi.
Prabarkaran
D
D
Godbole
M M
MM
D002540:Cerebral Cortex / Q000196:embryology* / Q000201:enzymology; D005865:Gestational Age; D006801:Humans; D007453:Iodide Peroxidase / Q000378:metabolism*; D007455:Iodine / Q000172:deficiency; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
D014284:Triiodothyronine; D013972:Thyrotropin; D007455:Iodine; D007453:Iodide Peroxidase; D013974:Thyroxine