Abstract: Objective Expressions of GABA and GABAAR-α1 in the brain of rats poisoned by Tetramine were analyzed to explore the intoxication mechanism.Methods Sixty rats were randomly divided into control,sham poisoned,high-dose poisoned(1.0 mg/kg tetramine) and low-dose poisoned(0.1 mg/kg) groups.The expressions of GABA and GABAAR-α1 in the brain of the poisoned rats were detected and analyzed by immunohistochemistry and imaging analyzer.Results The expressions of both GABA and GABAAR-α1 were diffusely seen in the brains of the control and shame poisoned rat groups with a moderate expression level,whereas the expressions of both GABA and GABAAR-α1 were decreased in the brains of the high-dose poisoned group.In the low-dose poisoned rat group,the expression of GABA initially decreased and reached its lowest level 6 hours after poisoning,and then started to show an increase and reached the level of control groups at day 3.The expressions level reached its peak at days 5-7 after poisoning and remained above the level of control groups till 10 days after poisoning.Similarly,the expression of GABAAR-α1 in the brains of the low-dose poisoned group initially decreased and reached its lowest level 6-12 hrs after poisoning,and then started to increase and reached the level of control groups at days 7-10 after poisoning,respectively.Conclusion The expression of both GABA and GABAAR-α1 decreased in the brains of the high-dose poisoned rat group and these changes of GABA and GABAAR-α1 expressions may be associated with underlying mechanism of tetramine poisoning.

Key words: GABA, GABAAR-α1, tetramine, immunohistochemistry