[The effects of lead exposure on primary cultured hippocampus neurons apoptosis and the expressions of Bcl-2, Bax, p53 and NOS1].

OBJECTIVE: To observe effects of plumbum on the apoptosis of primary cultured hippocampus neurons.

METHODS: After primary cultured hippocampus neurons of rats treated with different concentration of Pb (C2H3O2) (10, 50, 100 and 200 microg/ml), to observe the morphological changes of the apoptosis of hippocampus cells by Giemsa dyeing, to detect the rate of apoptosis by flow cytometry, to observe the expression of Bcl-2, Bax and p53 by immunocytochemical stain and to analyze quantitatively the average fluorescence intensity of free Ca2+ in kytoplasm of each concentration group by laser scanning confocal microscope (LSCM).

RESULTS: The results of Giemsa dyeing showed typically morphological changes of apoptosis after hippocampus neurons treated with certain concentration of Pb(C2H3O2), and had dose-dependent; The results of flow cytometry showed,after cells treated respectively in 50, 100, 200 microg/ml for 24h, that the rate of apoptosis increased and compared with the control group the difference of were all statistical significance (P < 0.01); The results of immunocytochemical stain showed that, with dose of Pb increasing, the expression of Bcl-2 protein decreased, the intensity of dyeing increasingly degraded and the expression of Bax and p53 was up-regulation, and compared with the control group, IOD value of cells had statistical significance (P < 0.01); The results of LSCM showed that the concentration of Ca2+ in kytoplasm was also increased with the dose of Pb (C2H3O2) increasing, and the average fluorescence intensity in groups of three concentration of Pb(C2H3O2) was all significantly higher than in the control group (P < 0.01) and had dose-response relation.

CONCLUSION: Plumbum might lead to different degrees of the apoptosis of hippocampus neurons. It is supposed that Pb in certain concentration range might affect the normal function of hippocampus neurons in learning and memory, and so on.