酮色林对脓毒症大鼠肺脏保护作用的实验研究

Protective effects of ketanserin on lung in septic rats

目的研究酮色林在脓毒症大鼠肺损伤的作用及其可能作用机制.方法72只SD雄性大鼠,随机数字法分为假手术组(Sham组)、脓毒症组(CLP组)、酮色林1 mg/kg组(K1组)及酮色林4 mg/kg组(K2组),每组18只大鼠又随机分为6、12和24 h三个亚组,每个亚组6只.Sham组采用盲肠探查术,CLP组、K1组及K2组均采用盲肠结扎穿孔法(CLP)建立脓毒症模型.造模成功后Sham组和CLP组腹腔注射生理盐水2.5 mL/kg,K1组腹腔注射酮色林1 mg/kg,K2组腹腔注射酮色林4 mg/kg,各亚组大鼠于造模成功后6、12及24 h采集标本.采用ELISA法检测血清中5-羟色胺(5-HT)、核转录因子-κB(NF-κB)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、肺表面活性物质蛋白-D(SP-D)、巨噬细胞炎性蛋-2(MIP-2)水平,测量肺泡灌洗液蛋白含量、肺湿/干质量、肺系数及肺水含量.结果①术后6、12、24 h,CLP组、K1组和K2组血清5-HT水平较Sham组明显升高;K1组、K2组血清5-HT水平较CLP组明显下降;K2组较K1组下降更明显.②术后6、12、24 h,CLP组、K1组和K2组血清NF-κB、TNF-α、IL-6水平较Sham组明显升高;K1组、K2组血清NF-κB、TNF-α、IL-6水平较CLP组明显下降;K2组较K1组下降更明显.③术后6、12、24 h,CLP组、K1组和K2组血清SP-D、MIP-2水平较Sham组明显升高;K1组、K2组血清SP-D、MIP-2水平较CLP组明显下降;K2组较K1组下降更明显.④术后6、12、24 h,CLP组、K1组和K2组肺湿/干质量、肺系数、肺水含量及肺泡灌洗液蛋白含量较Sham组明显升高;K1组、K2组肺湿/干质量、肺系数、肺水含量及肺泡灌洗液蛋白含量较CLP组明显下降;K2组较K1组下降更明显.⑤肺组织病理形态学改变:对照各组实验结果可以发现,肺部损伤程度由轻到重依次为:Sham组<k2组<k1组<CLP组。结论酮色林通过阻断外周5-HT信号传导,抑制炎症因子释放,在脓毒症中起到治疗作用。其机制可能为酮色林阻断外周5-HT在脓毒症中的促炎作用,降低肺脏通透性,减轻肺水肿,从而对脓毒症诱导的肺脏起到保护作用。

Objective To study the effect of ketanserin on lung injury in septic rats and its possible mechanism.Methods 72 SD male rats were randomly divided into sham operation group(Sham group),sepsis group(CLP group),ketanserin 1 mg/kg group(K1 group)and ketanserin 4 mg/kg group(K2 group);18 rats in each group were randomly divided into three subgroups of 6,12 and 24 h,with 6 in each subgroup.The sham group was treated with cecal exploration.The CLP group,K1 group and K2 group accepted cecal ligation and puncture(CLP)to establish sepsis models.After sesful modeling,the Sham group and the CIP group were itntperitoneally injeeted with 2.5 mL/kg nomal saline;the KI group was inapeitonoally injected with ketanserin I mg/kg,and the K2 group was itrperitoally niected with ketanserin 4 mg/kg.Rat specimeng were olleted at6,12 and24 h after sussful modeling.Senum levels of serotorin(5-HT),NF-κB,TNF-α,IL-6,SP-D and MIP-2 were measured by ELISA.The protein content of lung alreolar lavnge fluid,lung wet/dry weight,lung eoffcient arnd lung water content were measured.Results①At 6,12 and 24 ater operation,the levels of serum 5-HT in CLP group,K1 group and K2 group were eignificanly higher than those in Sham group;the levels of S-HT in K1 group and K2 group were si gifcantly lower than those in CLP goup:compared with KI group.the decrease of serum 5-HT level in K2 group was more obriows.②At 6,12 and 24 h after operation,the levels of serum NF-κB,TNF-α and IL-6 in CLP group,K1 group and K2 group were signifcantly higher than those in Sham group;the levels of serum NF-κB,TNF-α and IL-6 in K1 goup and K2 group were significantly lower than those in CLP group;and the deerease was more obrious in K2 group than in K1 goup.③At6,12 and 24 h after opention,the levels of serum SP-D and MIP-2 in CLP goup,K1 goup and K2 goup were significanuly higher than those in Sham group;the levels of serum SP-D and MIP-2 in K1 group and K2 group were lomer than those in CLP group;the deercease in the K2 group was more pronounced than that in the K1 goup.④At 6,12 aund 24 h afer operation,the lung wet/dry meight,lung ceficient,lung water content and protein content of lung alveolar lavage fluid in CLP group,KI group and K2 group were signifcandy higher than those in Shan group;those were sgnificanly lower in the K1 group and K2 goup than in CLP goup;the decreases of those indexes were more obvious in the K2 group than in K1 goup.⑤Puthological chunges of lung tssue:The experimental resuts showed that the degree of lung injury frorm slight to severe was:Sham group<K2 group<K1 group<CLP group.Conclusion Ketanserin inhibits the rcleae of ifanmalory factors by blocking peripheral 5-HT signaling and plays a therapeutie role in sepis.The mechanism may be that ketanserin blocks the proinflammatory effect of peripheral 5-HT in sepis,reduces lung permebility and pulmonury edema,thereby proteet the lung injury induced by sepsis.