Expression of neuron specific enolase gene in the brains of rats induced by iodine excess
10.3760/cma.j.issn.1000-4955.2009.04.015
- VernacularTitle:碘过量对大鼠脑神经元特异性烯醇化酶基因表达的影响
- Author:
Fang, ZHENG
;
Gang, GUO
;
Bao-li, WANG
;
Dong-chun, LIANG
;
Rui, ZHANG
;
Jing-yu, ZHANG
;
Xue-qin, ZHAO
;
Zu-pei, CHEN
- Publication Type:Journal Article
- Keywords:
Iodine;
Thyroid hormones;
Neurons;
Specific enolase
- From:Chinese Journal of Endemiology
2009;28(4):405-408
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe expression of neuron specific enolase (NSE) gene in the brain of rats induced by iodine excess. Methods One hundred and fifty one-month weaning Wistar rats were divided into ten groups according to 5 × 2 factorial experiment. Rats were fed with normal feedstuff and water of a series of iodine concentration by adding potassium iodide respectively: norrmal iodine (NI), five-fold high iodine (5HI), ten-fold high iodine(10HI), fifty-fold high iodine(50HI) and one hundred-fold iodine(100HI). After these rats were fed for three or six months, rat serum thyroid hormones were measured by radioimmunoassay including TT4, TT3, FT4, FT3, rT3 and the mRNA level of NSE in rat brain tissue was studied using RT-PCR technique. Results The levels of serum TT4 and TT3 were significantly different in five iodine level groups(F values were 18.867,27.287, both P < 0.01). The interaction between time and iodine level in TT4 was significant in our study(F values were 2.486, P < 0.05). The levels of TT4 and TT3 of 100 HI group at third and sixth month were lower than those of NI, 5HI, 10HI, 50HI groups in the same period (all P < 0.01). The levels of serum FT4, FT3 and rT3 were significantly different at different time(F values were 4.968,27.046,59.776 respectively, P < 0.05 or < 0.01) and in different iodine level groups(F values were 33.058,28.420,17.482 respectively, all P < 0.01). Moreover, the interaction between time and iodine level in FT3 and rT3 was significant in our study(F values were 6.894,5.233 respectively, both P < 0.01). FT4, FT3 and rT3 in 100HI group were lower than that of other iodine dosage groups at the same time (P < 0.05 or < 0.01). The levels of NSE mRNA in brain tissue was significantly different in five iodine level groups (F values were 29.006, P < 0.05). The levels of mRNA NSE of 100HI group in both three and six months (0.61 ± 0.19,0.61 ± 0.22) were all lower than that of any other groups[NI(0.73±0.13 and 0.72 ±0.26), 5HI (0.72 ± 0.15 and 0.72±0.16), 10HI (0.73 ±0.32 and 0.70±0.13), 50HI(0.71±0.18 and 0.69±0.31), all P < 0.05]. The results of correlation analyses show that the levels of serum FT3 and FT4 had correlations with the levels of NSE mRNA (P < 0.05) both in three and six months(r values were 0.987, 0.969 in three month, and 0.890, 0.910 in six month respectively). Conclusions The expression of NSE gene can tolerant the excess of iodine to a certain extent. Exposure to heavy excess iodine(100HI) can decrease the mRNA level of NSE gene. FT4 and FT3 may both have important roles on the regulation of NSE mRNA induced by excess iodine.
