[Effects of stress on hippocampal Glu-NMDAR pathway in rats and mechanism of zinc protection].

ABSTRACT

AIM: To observe the effects of stress on Glu uptake and NMDAR of hippocampus synaptosome in rats with different zinc status. METHODS: Stress model was established by photoelectric stimulus. The behaviors of rats were tested in open-field case. 3H-L-Glu was taken as radioligand to detect the NMDAR binding. Glu uptake was determined with radioimmunoassay. RESULTS: Compared with CT rats, ZD rats performed less movement in open-field test, both Bmax of NMDAR and 3H-L-Glu uptake of hippocampus in these rats were significantly decreased. Compared with corresponding non-stressed groups, the stressed groups appeared longer latency and less movement in open-field test. Increased Bmax of NMDAR and decreased 3H-L-Glu uptake were observed in all stressed rats, but only in SZD rats these indices showed statistical difference. CONCLUSION: Abnormal behaviors of rats induced by photoelectric stress were observed in open-field test, which was more serious in zinc deficiency rats. It is supposed that the Glu-NMDAR pathway is involved in the process of stress reaction. As it shows in our experiment, the changes of Bmax of NMDAR and 3H-L-Glu uptake of hippocampus synaptosome seems to be a part of the mechanisms of stress action.