大剂量地塞米松对内毒素肺损伤的保护作用

The protective effects of high- dose dexamethasone on the endotoxin lung injury

作者采用清醒绵羊内毒素急性肺损伤模型,观察了大剂量地塞米松(Dex)对肺损伤的保护作用.结果发现,预先给予Dex后,肺损伤反应明显减轻,肺动脉压显著降低(5.4±0.6～4.2±0.2 kPa,P<0.05),肺淋巴流量(23.5±7.4～11.0±6.7 ml/30 min,P<0.05)、血浆血栓素B_2(TXB_2,2.6±0.7～0.6±0.2ng/ml,P<0.01)和肺组织磷脂酶A_2(PLA_2,354±78～142±52U,P<0.01)活性均受到明显抑制;组织病理学显示,肺泡和肺间质水肿减轻,白细胞、红细胞渗出减少.表明Dex能抑制PLA_2活性,阻止TXB_2的升高,从而降低肺动脉高压和毛细血管通透性,减少细胞渗出,对内毒素急性肺损伤有保护作用.

Using an endotoxin lung injury sheep model with chronic lung lymph fistula, we observed the protective effects of high-dose dexamethasone (Dex)on lung injury. The results showed that Dex could attenuate pulmonary hypertention and lung lymph flow, improve the gas exchange, inhibit phospholipase A2 activity and synthesis of TXB2, reduce lung edeme and aggregation of neutrophil in the lung. All these suggest that Dex has a protective effect in the endotoxin lung injury.