Effect of chronic intermittent hypoxia on apoptosis of rat’s hippocampal cells and the expression of caspase-12 in immature rats

Objective: To explore the effect of chronic intermittent hypoxia on apoptosis of hippocampal cells and the expression of caspase-12 in immature rat’s. Methods: Forty male Sprague- Dawley rats (3～4 week,80～100 g) were randomly divided into four groups: 2-week intermittent hypoxia group (2IH),4-week intermittent hypoxia group (4IH),2-week control group with room air(2C) and 4-week control group with room air (4C), and ten rats in each group. Intermittent hypoxia model was induced by an intermittent hypoxia cabin,the in situ cell apoptosis in the hippocampus was detected with TUNEL staining. The expressions of caspase-12mRNA in the hippocampus were examined with RT-PCR. Immunohistochemical SP method was used to examine the expression of caspase-12 in the hippocampus. Results: Both the apoptosis index(AI)and the expressions of caspase-12 in hippocampus of intermittent hypoxia group were significantly higher than those in control group (P 0.01). Increasing the duration of hypoxic period, 4IH group had significantly higher levels of AI and the expression of caspase-12 than that of 2IH group. Conclusion: The expression of caspase-12 increases significantly and it shows that endoplasmic reticulum stress plays an important role in the course of apoptosis of immature rat’s hippocampal cells induced by chronic intermittent hypoxia.