虫草多糖预先给药对大鼠内毒素性急性肺损伤的影响

目的 评价虫草多糖预先给药对大鼠内毒素性急性肺损伤的影响.方法 雄性成年SD大鼠40只,体重190～220 g,随机分为5组(n=8):虫草多糖预先给药组(CP1-3,组)采用灌胃法分别给予虫草多糖1、2、3 g/ks,1次/12 h,连续6次,于最后1次给药后2 h时经股静脉注射内毒素5 mg/kg;急性肺损伤组(ALI组)以生理盐水1ml/100 g代替虫草多糖,其余方法同CP组;对照组(C组)以生理盐水1 ml/100 g代替虫草多糖和内毒素,其余方法同CP组.静脉注射内毒索后6 h时处死大鼠,计算肺湿干重比(W/D)、肺渗透指数(PPI);行支气管肺泡灌洗,对支气管肺泡灌洗液(BALF)行白细胞(WBC)和多形核白细胞(PMN)计数;测定肺组织及BALF肿瘤坏死因子α(TNF-α)水平,并行肺组织病理学评分.结果 与C组比较,ALI组和CP1～3组肺W/D、PPI、WBC和PMN计数、肺组织病理学评分、肺组织和BALF TNNF-α水平均升高(P<0.05或0.01);与ALI组比较,CP1组上述指标差异无统计学意义(P>0.05),CP2,3组上述指标降低(P<0.05);与CP2组比较,CP3组PMN计数、肺组织病理学评分、肺组织和BALFTNF-α水平降低(P<0.05).结论 虫草多糖预先给药可减轻大鼠内毒素性急性肺损伤,且呈剂量依赖性,其机制可能与虫草多糖降低肺组织炎性反应有关.

Effect of Cordyceps polysaccharide pretreatment on endotoxin-induced acute lung injury in rats

Objective To evaluate the effects of Cordyceps polysaccharide (CP) pretreatment on endotoxin-induced acute lung injury (ALI) in rats.Methods Forty adult male SD rats were randomly divided into 5 groups ( n = 8 each) : CP1-3 group, ALI group and control group (group C). Group CP1-3 received CP 1, 2 and 3 g/kg by intragastric gavage every 12 h for 6 times respectively, and then received LPS 5 mg/kg iv through the femoral vein 2 h after the last administration. Croup ALI received normal saline 1 ml/100 g instead of CP, and the rest methods were the same as those described in group CP. Group C received normal saline 1 ml/100 g instead of CP and LPS, and the rest methods were the same as those described in group CP. The animals were killed 6 h after injection of LPS. The lungs were removed for determination of W/D lung weight ratio, pulmonary permeability index (PPI), WBC and PMN counts in broncho-alveolar lavage fluid (BALF) , and levels of TNF-α in lung tissues and BALF, and microscopic examination.Results Compared with group C, W/D lung weight ratio, PPI, WBC and PMN counts in BALF, lung pathological scores and levels of TNF-α in lung tissues and BALF were significantly increased in group ALI and CP1-3 ( P < 0.05 or 0.01). No significant differences were found in the indices mentioned above between group CP1 and group ALI ( P > 0.05) . The indices mentioned above were significantly lower in group CP2,3 than in group ALI ( P < 0.05) . PMN counts in BALF, lung pathological scores and levels of TNF-α in lung tissues and BALF were significantly lower in group CP3 than in group CP2 ( P < 0.05) . Conclusion Cordyceps polysaccharide pretreatment can attenuate LPS-induced ALI in a dose-dependent manner through inhibition of inflammatory response in rats.