[Relationship between apoptosis of rat hippocampus cells induced by aluminum and the copy of the bcl-2 as well as bax mRNA].

OBJECTIVE: To explore the effects of aluminum chloride (AlCl3) on the apoptosis of rat hippocampus cells and the relationship between the apoptosis and the expression of the bcl-2 as well as bax mRNA. METHODS: 40 SD rats, adult and healthy, were divided into 4 groups randomly: normal saline, Al3+ 2.5 mg/kg, 5 mg/kg, 10 mg/kg. They were exposed to AlCl, by intraperitioneal injection at the dose of 0.2 ml/d for 60 days. After exposure, the apoptosis of hippocampus cells were measured by method of TUNEL. The expression of bcl-2 mRNA and bax mRNA in rats' hippocampus were measured by RT-PCR. The results were analyzed by the gelatum analyzing system. RESULTS: The rates of apoptosis in hippocampus cells in Al3+ 5 mg/kg group and Al3+ 10 mg/kg group were significantly higher than that of controls (P < 0.05). But Al3+ 2.5 mg/kg group was not significantly higher than that of control (P > 0.05), and was significantly decreased in hippocampus cells in Al3+ 5 mg/kg and 10 mg/kg group compared with the control group (P < 0.05). The expression of bcl-2 mRNA was significantly decreased in every aluminum treatment group compared with the control group (P < 0.05). The expression of bax mRNA was significantly increased in every aluminum treatment group compared with the control group (P < 0.05). There was negative correlation between AI and the expression of Bcl-2 (r = -0.909, P < 0.01). There was positive correlation between Al and the expression of Bax (r = 0.871, P < 0.01). CONCLUSION: Aluminum can induce apoptosis in rat hippocampus cells through the downwards regulation of bcl-2 mRNA, the upwards regulation of bax mRNA expression.