Objective: To investigate the effects of cyclosporine A (CsA), a powerful inhibitor of mitochondrial permeability transition pore (MPTP), on pneumocyte apoptosis, the release of cytochrome C and the activity of caspase-3 after lung ischemia/reperfusion, and explore the mechanisms.
Methods: Single lung in situ ischemia/reperfusion animal model was used. 30 SD rats were randomly divided into three groups (n = 10): sham (S) group, ischemia/reperfusion (I/R) group and cyclosporine A (CsA) group. Apoptosis of pneumocyte was assessed by TUNEL method, cytochrome C (CytC) in cytoplasm was detected by immunohistochemistry techniques, and the activity of caspase-3 was measured with spectrophotometer.
Results: The content of CytC in cytoplasm, the activity of caspase-3, and the value of apoptosis index (AI) in ischemia/reperfusion group were evidently higher than that in S group (P < 0.01). CsA suppressed apoptosis as well as CytC release and caspase-3 activity (P < 0.01).
Conclusion: CsA can prevent the release of cytochrome C, block the apoptosis of pneumocyte accordingly maybe by closing the MPTP.