[Effects of zinc on the expression of metallothionein isoforms in hippocampus of stressed rats].
OBJECTIVE
This study was conducted to evaluate the effects of different doses of zinc on the expression of metallothionein isoforms in hippocampus of stressed rats.


METHODS
The animal model of psychological stress was developed by restraint stress for four weeks. Wistar rats were randomly assigned to eight groups as follows: control group, zinc deficiency group, pair-feed group, zinc complementarity group and their corresponding stressed groups.


RESULTS
In zinc deficiency group, plasm zinc content was decreased, while in zinc complementarity group it's slightly increased. On the one hand, the expressions of metallothionein in brain and MT-1 mRNA, MT-3 mRNA in hippocampus were downregulated in zinc deficiency group, however, their expressions were evidently enhanced in stressed zinc deficiency group. On the other hand, inductions of metallothionein and it' s mRNAs in zinc complementarity group were increased, furthermore, stressed zinc complementarity group has more significantly yield of metallothionein and it' s mRNAs. In addition, the levels of plasma cortisol, IL-6, IL-1 and NO were increased clearly in zinc deficiency group and stressed zinc deficiency group.


CONCLUSIONS
Our results suggested that zinc deficiency may decrease while zinc complementarity increase the expressions of metallothionein in brain and MT-1 mRNA, MT-3 mRNA in hippocampus, moreover, stress can increased their expressions dramatically. The impairment of stress on body may be involved with the nutrition status of zinc, and zinc deficiency can lower the body's resistibility to stress.
Chen
Wei-qiang
WQ
Institute of Health and Environmental Medicine, Academy of Military Medical Sciences, Tianjin 300050, China.
Cheng
Yi-yong
YY
Li
Shu-tian
ST
Wang
Dong-lan
DL
Yu
Zhijie
Z
Hong
Yan
Y
D000818:Animals; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012149:Restraint, Physical; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013315:Stress, Psychological / Q000378:metabolism*; D015032:Zinc / Q000494:pharmacology*
D020033:Protein Isoforms; D012333:RNA, Messenger; D008668:Metallothionein; D015032:Zinc