戊乙奎醚联合机械通气对急性呼吸窘迫综合征大鼠炎症的影响

Effects of Penehyclidine Hydrochloride Combined with Mechanical Ventilation on Inflammation in Rats with ARDS

目的观察戊乙奎醚联合机械通气对油酸静脉注射诱导的大鼠急性呼吸窘迫综合征(ARDS)肺组织炎症反应的影响。方法通过颈静脉注射油酸(0.15 mL/kg)制作大鼠ARDS模型。32只成年健康雄性SD大鼠按简单随机法分为4组,每组8只:对照组、油酸组、戊乙奎醚组及机械通气组。油酸注射前30 min经腹腔注入戊乙奎醚0.5 mg/kg制作大鼠ARDS模型。机械通气组(戊乙奎醚+机械通气)呼吸机参数设置:潮气量(V T)=4 mL/kg,呼吸频率(R)=70次/min,吸呼比(I∶E)=1∶2,吸入氧浓度(FiO2)=21%。机械通气4 h后为实验终点,测定大鼠动脉血氧分压(PaO2)并计算氧合指数(PaO2/FiO2),肺组织湿干重比(W/D);光镜下观察肺组织病理改变,并计算病理评分;酶联免疫吸附法(ELISA)测定肺组织匀浆中髓过氧化酶(MPO)、白细胞介素8(IL-8)及核转录因子κB(NF-κB)含量。结果油酸组大鼠肺间质明显水肿,肺出血及灶性肺不张,肺组织大量炎细胞浸润,肺微血管充血明显;与对照组比较,油酸组大鼠肺组织病理评分(8.63±2.20比1.38±0.92)和W/D比值明显升高(8.37±0.99比4.08±0.65,P均<0.01),PaO2/FiO2明显降低[(206±32)mm Hg比(428±28)mm Hg),P<0.01];肺组织匀浆中MPO[(33.91±1.43)ng/mL比(20.92±1.40)ng/mL)]、IL-8[(809±39)ng/L比(583±91)ng/L]和NF-κB[(1163±105)ng/L比(803±130)ng/L]高于对照组大鼠(P均<0.01)。戊乙奎醚组、机械通气组炎细胞浸润、肺水肿、肺出血等改变均较油酸组轻,肺组织病理评分(7.12±0.75和6.03±0.87比8.63±2.20)、W/D比值(6.38±1.51和4.00±2.27比8.37±0.99)均较油酸组明显降低(P均<0.05),PaO2/FiO2明显升高[(256±33)和(309±61)比(206±32)mm Hg,P均<0.05],肺组织匀浆MPO[(28.40±3.51)和(24.23±1.24)比(33.91±1.43)ng/mL,P均<0.05]、IL-8[(768±49)和(700±55)比(809±39)ng/mL,P均<0.05]、NF-kB[(1159±104)和(946±91)比(1163±105)ng/mL,P均<0.05]均低于油酸组,而机械通气组改变较戊乙奎醚组改善更为明显(P均<0.05),但均未达到对照组水平(P均<0.05)。结论戊乙奎醚能减轻油酸静脉注射诱导ARDS大鼠肺组织炎症反应,戊乙奎醚联合机械通气的作用优于戊乙奎醚单独使用;通过抑制肺组织炎症反应可能是戊乙奎醚联合机械通气对油酸性ARDS大鼠实施肺保护作用的机制之一。

Objective To observe the effects of penehyclidine hydrochloride （PHCD） combined with mechanical ventilation （MV） on inflammatory response in rats with ARDS induced by oleic acid （OA）. Methods The rat ARDS model was established by OA via intravenous injection （iv）. 32 adult healthy male SD rats were randomly divided into four groups, ie. a normal control group （group C：intra-peritoneal injection of a same amount of normal saline and intravenous injection of a same amount of normal saline respectively rather than PHCD ）, a model group （ group A1 ） , a PHCD group （ group A2 ： intra-peritoneal injection of 0. 5 mg/kg PHCD 30 minutes before OA iv） and a PHCD ＋ MV group （group A3：VT = 4 mIZkg, respiratory rate = 70 beats/min, I： E = 1 ： 2, FiO2 = 21% ）. Four hours after OA iv, arterial partial pressure of oxygen （PaO2 ） was measured, and the oxygenation index （PaO2/FiO2 ） as well as wet/dry weight ratio （W/D） of lung tissue were calculated respectively. The pathological changes of lung tissue was observed through light microspcope. Interlukin-8 （IL-8）, myeloperoxidase （MPO） and NF-KB in lung tissue homogenate were measured by enzyme linked immunosorbent assay （ELISA）. Results Extensive pneumonedema,pneumorrhagia, focal atelectasis and amour of inflammatory cells infiltration in lung tissues were all revealed in ARDS rats. Lung injury score （8.63±2. 20 vs. 1.38±0.92） ,W/D ratio （8.37±0.99 vs. 4. 08±0. 65） were all higher in the ARDS rats than those in group C （ all P 〈 0. 01 ）. PaOJFiO2 was lower in group A1 than that in group C [（206±32） mm Hg vs. （428 ±28） mm Hg,P〈0.01]. The concentrations of MPO [ （33.91±1.43 ） ng/mL vs. （20. 92±1.40） ng/mL） ] , IL-8 [ （809±39 ） ng/L vs. （583±91 ） ng/L] and NF-KB （ 1163±105） ng/L vs. （803±130） ng/L] in lung tissue homogenate were significantly increased in the ARDS rats than those in group C （ all P 〈 0. 01 ）. Pathological changes of lung tissue （ including pneumonedema, pneumorrhagia, ateleetasis and inflammatory ceil infiltration, etc. ） obviously improved when treated by PHCD or/and PHCD combined with MV （all P 〈 0. 05 ）. PaOJFiO2 in group A2 and A3 were both significantly increased when compared with group A1 （ both P 〈 0. 05 ）. Meanwhile, W/D ratio,lung injury score, and concentrations of MOP, IL-8 and NF-KB were sharply decreased in group A2 and A3 （ all P 〈 O. 05 ）. The improvement in all above indices were more significant in group A3 than those in group A2, despite all those indices failed to meet the levels of normal rats （ all P 〈 0.05 ）. Conclusion PHCD can inhibit the inflammatory response in ARDS rats induced by OA iv, through which it protect the lung tissue from injury induced by OA. The protective role of PHCD plus MV is superior to that of PHCD only.