大鼠角叉菜胶胸膜炎渗出白细胞磷脂酶D活性的变化

目的　观察在整体炎症过程中炎症白细胞磷脂酶D(PLD)活性的变化和炎症的关系。方法　采用大鼠角叉菜胶胸膜炎模型 ,以渗出液量和细胞数及渗出液中髓过氧化物酶活性 (中性粒细胞脱颗粒指标 )作为炎症程度。用酶偶联比色法测定白细胞PLD活性。结果　正常大鼠外周血白细胞PLD活性极低 ,为 ( 0 14± 0 0 3) μmol·g-1·min-1。致炎后各时间点胸膜腔渗出白细胞的PLD活性明显升高 ,分别可达 40～ 6 0倍 ,并在 3h达峰值 ,明显早于炎症高峰 ( 12h)。不同剂量 ( 5 0 0 μg和 10 0 0 μg)角叉菜胶可引起致炎 12h明显不同程度的炎症 ,但渗出白细胞PLD活性两者差别不大。低剂量吲哚美辛 ( 2mg·kg-1,ip)和地塞米松 ( 0 1mg·kg-1,ip)均明显抑制致炎 6h大鼠胸膜腔的渗出 ,但渗出白细胞PLD活性与对照组相比差别无显著性。结论　大鼠角叉菜胶性胸膜炎白细胞PLD活性显著升高 ,提示PLD活性升高在该炎症模型中是原发性表现 ,低剂量吲哚美辛和地塞米松的抗炎机制与PLD无关

Changes of phospholipase D activity of exudate leukocytes in rat carrageenan-induced pleurisy

AIM To observe the relationship between the changes of phospholipase D(PLD) activity in inflammatory leukocytes and inflammation in vivo METHOD Inflammation was carried out by the carrageenaninduced pleurisy in the rat, and the exudate volume, total account of influxed cells and total activity of myeloperoxidase in exudate which was the index of degranulation of neutrophils were measured as the severity of inflammation PLD activity was assessed by the enzymecoupled spectrophotometric assay RESULT PLD activity of influxed leukocytes increased 40～60 times than that of peripheral blood leukocytes taken from untreated animals which contain low levels of PLD activity 〔(014±003) μmol·g -1 ·min -1 〕, and the influxed cellassociated PLD activity peaked at 3 h after injection of the carrageenan However,the severity of inflammation peaked at 12 h after carrageenan injection 500 μg and 1000 μg carrageenan caused dosedependent exudation in the pleural cavity but no significant difference of PLD activity was observed at 12 h after injection of carrageenan Indomethacin(2 mg·kg -1 , ip) and dexamethasone(01 mg·kg -1 , ip) both significantly attenuated the pleural exudation and cellular influx at 6 h after injection of carrageenan but had no significant effects on influxed cellassociated PLD activity CONCLUTION These findings indicate that the PLD activity of inflammatory cells in rat carrageenaninduced pleurisy increased, and suggest that this increase of PLD activity is not a secondary but a primary effect in the present model of acute inflammation, and antiinflammatory mechanisms of low dose of indomethacin and dexamethasone are not linked to PLD