Approach to the relationship between the expression of metallothionein-Ⅲ mRNA and free zinc contents
- VernacularTitle:前脑缺血再灌注后海马金属硫蛋白-Ⅲ mRNA表达和游离锌离子变化的关系探讨
- Author:
Zhujuan ZHOU
;
Jian ZHENG
;
Ying HE
- Publication Type:Journal Article
- Keywords:
Metallothionein;
Zinc;
Brain ischemia;
Reperfusion
- From:
Chinese Journal of Neurology
2001;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the induction mechanism of MT ⅢmRNA in the brain after cerebral ischemia.Methods The forebrain ischemia reperfusion model was established in rats. The changes of the expression of MT Ⅲ mRNA in hippocampus after forebrain ischemia reperfusion were observed by in situ hybridization method. The changes of free Zn 2+ in hippocampus after forebrain ischemia reperfusion was examined using Zn 2+ specific fluorescent probe(TSQ). The Zn 2+ chelator (CaEDTA) was injected into the lateral ventricles for determining influences of Zn 2+ on the MT Ⅲ mRNA expression and the neuronal damage after forebrain ischemia/reperfusion.Results (1) The expression of MT ⅢmRNA in hippocampus increased gradually after cerebral ischemia and reached the peak in 96 hours after reperfusion. Seven days after reperfusion the expression of MT ⅢmRNA reduced to the normal level. (2) Zn 2+ fluorescence in the hilus of dentate gyrus, CA 3 region and the stratum radiatum and stratum oriens of CA 1 decreased slightly at 48 hours after reperfusion. From 72 to 96 hours after reperfusion, the fluorescence returned to normal, but some new fluorescence dots appeared in pyramidal neurons of CA 1 and the hilus of dentate gyrus increased gradually. Seven days after reperfusion, the fluorescence returned to normal. (3) The cell membrane impermeable Zn 2+ chelator could reduce the intracellular concentration of free Zn 2+ and the expression of MT Ⅲ mRNA.Conclusion The expression of MT Ⅲ mRNA can be induced by the increase in the concentration of intracellular free Zn 2+ after forebrain ischemia/reperfusion.
