[Effects of various iodin-nutritional on activity of T4 5'-and 5-deiodinase in rat brain].
OBJECTIVE
To investigate the changing of T4 5'-and 5-deiodinase within rat brain under various iodin-nutritional states.


METHODS
Animal model of iodine-deficiency rat was performed and the rats were divided into 4 groups by the intake of iodine-nutrition, and then killed at an age of 20 days. The thyroid hormones level in serum was measured by ELISA and the activity of T(4) 5'-and 5-deiodinase within brain was analyzed.


RESULTS
In less-iodine (LI) group,TT4 and FT4 were accounting for 3.5% of the neutral-iodine (NI) group's, and FT3 was 174.0% of NI group's (P < 0.05). In NI group,TT4 and FT4 were 114.5% and 127.7% of NI group's (P < 0.05). In high-iodine (HI) group, TT4 and FT4 were 61.86% and 62.0% of NI group's, and FT3 was 184.9% of NI group's (P < 0.05). In LI group, the activity of T4 5'-deiodinase tissue of per gram (1.95 +/- 0.32) ngT3.microgT4(-1).h was significantly higher than that of NI group (P < 0.05), and the activity of 5-deiodinase (1.38 +/- 0.21) ngrT3.microg T4(-1).h(-1) is significantly less than that of NI group (1.59 +/- 0.23) (P < 0.05). In HI group the activity of T4 5'-and 5-deiodinase tissue of per gram (1.12 +/- 0.19 and 1.73 +/- 0.36) ngrT3.microgT4(-1).h(-1)was significantly less than that of NI group (P < 0.05).


CONCLUSIONS
The activity of T4 5'-deiodinase in iodine deficiency heightens and that in iodine excess is debased, the activity of T4 5-deiodinase in iodine deficiency and in iodine excess is debased.
Guo
Shan-yi
SY
Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China.
Zuo
Ai-jun
AJ
Liu
Nian-qing
NQ
Zhao
Xue-qin
XQ
Guo
Ruo-lin
RL
Zhang
Fang
F
Zhang
Jing-yu
JY
D000818:Animals; D001921:Brain / Q000201:enzymology*; D005260:Female; D007453:Iodide Peroxidase / Q000378:metabolism*; D007455:Iodine / Q000008:administration & dosage* / Q000172:deficiency*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine; D007455:Iodine; D007453:Iodide Peroxidase; D013974:Thyroxine