Effects of subacute 1-bromopropane inhalation on the expression of SYP,GluR2 and NR2B in hippocampus of male rats / 中国职业医学

ABSTRACT

OBJECTIVE: To study the potential effects of subacute 1-bromopropane( 1-BP) inhalation on the expression of synapse specific biomarkers synaptophysin( SYP),glutamate receptor 2( GluR2) and N-methyl-D-aspartate receptor 2B( NR2B) in the hippocampus of male rats. METHODS: Forty-eight specific pathogen free adult male Wistar rats were randomly divided into control group,low-,medium-,and high-dose groups according to body weight. Each group consisted of 12 rats. By dynamic inhalation intoxication method,the control group was exposed to fresh air,the dose groups were given 1 250,2 500 and 5 000 mg / m3 of 1-BP respectively,6 hours per day,5 days per week for continuous 4 weeks. After the exposure,the rats were executed and the whole brains were separated into cerebrum( included hippocampus),brainstem and cerebellum. Real time quantitative polymerase chain reaction and Western blot were used for detection of SYP,GluR2 and NR2 B mRNA and protein expression in hippocampus. RESULTS: Slow response and muscle strength descended in hind limbs were found in high-dose group in the 3rd week. Body weights of rats in high-dose group were lower than those of control group from the 1st to the 4th week( P < 0. 01). Weights of whole brain,cerebrum and brainstem in high-dose group were lower than those of control group( P < 0. 05). Rats in high-does group were found neuron necrosis in hippocampus cornu ammonis 3 and dentate gyrus region. No significant difference was found in SYP,GluR2 and NR2 B mRNA relative expression in all groups( P > 0. 05). No significant difference was found in SYP protein relative expression in different groups( P > 0. 05). The GluR2 protein relative expression in high-dose group was lower than that of control group( P < 0. 05). The NR2 B protein relative expression was higher than that of control group( P < 0. 05). CONCLUSION: The GluR2 and NR2 B protein expression in hippocampus can be potential biomarkers for 1-BP central neurotoxicity,but its physiological meaning needs further elucidation.