Study on phospholipase A2 activation and antagonizing effect of fructose-1,6-diphosphate in endotoxin-induced acute lung injury in rabbits / 解放军医学杂志

ABSTRACT

Objective To study the changes in activity of phospholipase A2 (PLA2) in the course of endotoxin (ET) induced acute lung injury (ALI) inrabbits and the antagonizing effect of fructose-1, 6-diphosphate (FDP), in order to evaluate the therapeutic effect of FDP on ET-induced ALI. Methods Flapeared white rabbits were randomly assigned to three groups control group (group A), ET challenge group (group B) and treatment group (ET challenged followedby FDP, group C). Group A animals were injected with saline (2ml/kg) as control. Group B animals were injected with ET (500μg/kg) solution followed by saline. Total amount of liquid was 2ml/kg. Group C animals were given the same amount of ET solution followed by injection of FDP (300mg/kg) solution. Total amount of liquid was also 2 ml/kg. During the experiment, respiratory rate, heart rate, blood pressure, arterial blood gases and the plasma PLA2 activity were determined at 0h, 0. 5h, 2h, 4h and 6h respectively. The rabbits were sacrificed at 6h, pulmonary PLA2 activity was assessed, and the pathologic changes in pulmonary tissues were examined with light microscope and transmission electron microscope. Results Compared with group A,rabbits of group B manifested the typical characters of ALI after ET injection, and the PLA2 activity in both serum and pulmonary tissue was much higher than those of group A (P＜0. 01).Values of the PLA2 activity in group C were between those of the two former groups. At the rame time, obvious pathological changes indicating lung injury were observed in group B and only mild pathological changes could be discerned in group C. Conclusion Activation of PLA2 activity is an important factor in pathogenesis of ET-induced ALI. FDP can antagonize the PLA2 activity and protect rabbits from early ET induced ALI to a certain extent.