The relationship between platelet endothelial cell adhesion molecule-1 and paraquat-induced lung injury in rabbits

BACKGROUND:Platelet endothelial cell adhesion molecule-1(PECAM-1),also known as CD31,is mainly distributed in vascular endothelial cells.Studies have shown that PECAM-1 is a very significant indicator of angiogenesis,and has been used as an indicator for vascular endothelial cells.The present study aimed to explore the relationship between the expression of PECAM-1 and the degree of acute lung injury(ALI) and fibrosis in paraquat(PQ) induced lung injury in rabbits.METHODS:Thirty-six adult New Zealand rabbits were randomly divided into three groups(12rabbits in each group) according to PQ dosage:8 mg/kg(group A),16 mg/kg(group B),and 32 mg/kg(group C).After PQ infusion,the rabbits were monitored for 7 days and then euthanized.The lungs were removed for histological evaluation.Masson staining was used to determine the degree of lung fibrosis(LF),and semi-quantitative immune-histochemistry analysis to determine the expression of PECAM-1.Pearson's product-moment correlation analysis was performed to evaluate the relationship between the expression of PECAM-1 and the extent of lung injuries expressed by ALI score and degree of LF.RESULTS:Rabbits in the three groups showed apparent poisoning.The rabbits survived longer in group A than in groups B and C(6.47±0.99 days vs.6.09±1.04 days vs.4.77±2.04 days)(P<0.05).ALI score was lower in group A than in groups B and C(8.33±1.03 vs.9.83±1.17 vs.11.50±1.38)(P<0.05),and there was statistically significant difference between group B and group C(P=0.03).LF was slighter in group A than in groups B and C(31.09%±2.05%vs.34.37%±1.62%vs.36.54%±0.44%)(P<0.05),and there was statistically significant difference between group B and group C(P=0.026).The PEACAM-1 expression was higher in group A than in groups B and C(20.31%±0.70%vs.19.34%±0.68%vs.18.37%±0.46%)(P<0.05),and there was statistically significant difference between group B and group C(P=0.017).Pearson's correlation analysis showed that the expression of PECAM-1 was negatively correlated to both ALI score(Coe=-0.732,P=0.001)and degree of LF(Coe=-0.779,P<0.001).CONCLUSIONS:The PECAM-1 expression significantly decreases in New Zealand rabbits after PQ poisoning,and the decrease is dose-dependent.The PECAM-1 expression is negatively correlated with ALI score and LF,showing a significant role in the development of lung injuries induced by PQ.