摘要
Objective To observe the influence of hypotherrnic circulatory arrest （HCA） on the apoptotic processes of neurons in the hippocampus and the expression of the related genes Bcl-2 and Bax, and compare to the intermittent antegrade cerebral perfusion. Methods Eighteen dogs were randomly divided into three groups： control group （6 animals, underwent normal temperature cardiopulmonary bypass, NCPB）, HCA group （6 animals, underwent HCA for 1 h）, and HCA ＋ IACP group （6 animals, underwent HCA for 1 h, combined with intermittent antegrade cerebral perfusion （IACP） every 15 min）. The hippocampus tissue was retrieved 2h after the CPB discontinued The expression of Bcl-2 and Bax were examined with immunohistochemistry method. The cytomorphologic changes of the hippocampus tissue were investigated with transmission electron microscopy （TEM）. Results The immunohistochemical staining showed that Bax protein levels were significantly higher in HCA group than in the other two groups （P〈0.01）, while Bcl-2 protein levels were significantly higher in HCA ＋ IACP group than that of the other two groups （P〈0.01）. Meanwhile, the TEM results showed that there was no apoptosis of neurons in control group, but neuronal apoptotic changes could be clearly observed in HCA group, and only a small amount of apoptotic neurons were seen in HCA ＋ IACP group. Conclusions HCA alone can induce neuronal apoptosis in the hippocampus. IACP during the HCA period has a protective effect on the cerebral tissue through suppressing apoptosis by decreasing Bax expression and increasing Bcl-2 expression.
