地塞米松或茶碱对血小板活化因子诱导的嗜酸性粒细胞活化的影响

目的:血小板活化因子(PAF)可诱导嗜酸性粒细胞(EOS)脱颗粒产生低密度嗜酸性粒细胞(HE),本研究旨在探讨地塞米松、茶碱对上述过程产生的影响。方法:分离正常人外周血EOS,观察不同密度EOS的组织学差别,测定地塞米松、茶碱对PAF诱导的EOS脱颗粒和正常密度EOS(NE)向低密度EOS(HE)转化的影响。结果:低密度嗜酸性粒细胞颗粒缩小;10^-5mmol/L地塞米松或10mg/L茶碱可使17.87%±2.16%或14.08%±2.42%的正常密度嗜酸性粒细胞转化为低密度嗜酸性粒细胞,与血小板活化因子组比较差异显著(P<0.05,P<0.01);同样浓度的地塞米松和茶碱分别使PAF诱导的嗜酸性粒细胞过氧化物酶的释放量下降至(101.17±10.32)mg/L、(110.85±4.16)mg/L及(100.53±9.65)mg/L、(106.94±10.11)mg/L(P<0.05,P<0.01)。结论:EOS脱颗粒是HE产生的原因之一;地塞米松、小剂量茶碱可以抑制PAF对EOS的活化,这可能是它们抗炎作用的机制之一。

Effect of dexamethasone or theophylline on platelet-activating factor-induced eosinophils

AIM: To elucidate the effects of platelet-activating factor (PAF) on eosinophil activation and the action of dexamethasone or theophylline during this process. METHODS: Eosinophils (EOS) from the peripheral blood of normal subjects were isolated. The hypodense eosinopil (HE) and normodense eosinophil (NE) were studied with electron microscopy. The effects of PAF on eosinophil activation and the action of dexamethasone or theophylline during the above process were measured. RESULTS: Hypodense eosinophil had significantly smaller individual granules than normodense eosinophil had. PAF induced eosinophil peroxidase release, and generated. Eosinophils incubated with 10^-8 mmol/L PAF and 10^-5 mmol/L dexamethasone released (101.17±10.32) mg/L eosinophil peroxidase (P<0.05). Eosinophils incubated with 10^-9 mol/L PAF and 10^-5 mmol/L dexamethasone caused a decrease in eosinophil peroxidase (110.85±4.16) mg/L and induced the generation of hypodense eosinophil (17.87%±2.16%). Eosinophils incubated with 10^-8 mmol/L PAF and 10 mg/L theophylline released (100.53±9.65) mg/L eosinophil peroxidase (P<0.05). Eosinophils incubated with 10^-9 mol/L PAF and 10 mg/L theophylline caused a similar decrease in eosinophil peroxidase (106.94±10.11) mg/L and induced the generation of hypodense eosinophil (14.08%±2.42%). CONCLUSIONS: Eosinophil degranulation is one of the reasons by which hypodense eosinopils develop. PAF induced eosinophil degranulation, so generated hypodense eosinopils. Dexamethasone and theophylline inhibited above effects.