Abstract: AIM: To explore relationship between apoptosis in the lung tissues and lung ischemia reperfusion injury, and observe effects of PNS by regulating apoptosis in lung ischemia reperfusion injury. METHODS: Single lung in situ ischemia reperfusion animal model was used. Eighty-four Japanese white rabbits were randomly divided into control group (Control), ischemia reperfusion 1h group (IR1h), IR3h, IR5h, Panax Notoginseng Saponins 1h group (PNS1h), PNS3h and PNS5h. The terminal deoxynucleotidyl transferase-mediate dUTP end labeling (TUNEL) and in situ hybridization were used to observe apoptosis; Fas、FasL mRNA and Caspase-3 mRNA expression in various phases of lung ischemia reperfusion; DNA fragmentation was observed by polyacrylamide gel electrophoresis (PAGE). RESULTS: Cell apoptosis (IR5h:22.08±1.93;Control:2.04±0.67) in lung tissues of rabbits with lung ischemia reperfusion were significantly higher than in Control group (all of P<0.01), especially in pulmonary vascular endothelial cells and alveolar epithelial cells. Fas/FasL mRNA and Caspase-3 mRNA (IR5h:0.241±0.029; Control:0.121±0.015) were up-regulated in lung tissues of lung ischemia reperfusion injury than in those of Control groups (all of P<0.01). The PNS suppressed apoptosis as well as expression of Fas/FasL mRNA and Caspase-3 mRNA (PNS5h:0.199±0.020, IR5h:0.241±0.029, all of P<0.01). There was a significant correlation between expression of Fas/FasL mRNA、Caspase-3 mRNA and cell apoptosis (all of P<0.01). DNA ladder appeared in IR5h group, but not seen in PNS5h group. CONCLUSIONS: The protective effects of PNS include suppressing the activation of Fas/FasL system and blocking apoptosis in lung tissues of lung ischemia reperfusion rabbits.

Key words: Lung, Reperfusion Injury, Apoptosis, Fas / FasL, Caspase-3, Panax Notoginseng Saponins