丙酮酸乙酯对脓毒症大鼠肠黏膜屏障功能保护作用的研究

目的 观察丙酮酸乙酯(ethyl pyruvate ,EP)干预治疗对脓毒症大鼠生存率和肠黏膜屏障的影响.方法 ①EP对脓毒症大鼠生存率的影响:无特定病原雄性SD大鼠100只随机分为假手术组(A组)、脓毒症组(B组)、EP早期治疗组(C组)及EP延迟治疗组(D组),每组25只,利用盲肠结扎穿孔法(cecal ligation and puncture,CLP)制作大鼠脓毒症模型,各组均于术后6、12、18、24、36、48、60、72 h腹腔内注射给药3 mL,C、D组分别于术后6、12 h开始予EP(40 mg/kg),A、B两组同法予等量林格乳酸钠溶液(ringer lactate solution ,RLS),每隔12 h记录死亡情况,分析比较5 d生存率;②EP对脓毒症大鼠肠黏膜屏障的影响:80只无特定病原雄性SD大鼠随机分为四组,每组20只,分组及给药方法与方法一相同,术后24、48 h各处死10只.测定各时间点血浆D-乳酸、DAO的变化,同时用透射电镜观察术后48 h肠黏膜上皮细胞超微结构的变化.采用Kaplan- Meier生存分析法进行生存分析,多组均数间比较采用单因素方差分析的方法, 多组均数间两两比较采用SNK-q检验,P＜0.05为差异有统计学意义.结果 A、B、C、D四组大鼠5 d生存率分别为100%、24%、68%、56%,与B组相比,C、D组大鼠5 d生存率明显提高(P<0.05),C、D组间差异无统计学意义(P＞0.05);与B组相比,C、D组术后24 h和48 h血浆D-乳酸含量明显下降(P<0.01);与B组相比,C组、D术后24 h和48 h血浆DAO活性明显下降(P<0.01),C、D组术后24、48 h血浆D-乳酸含量、DAO活性差异无统计学意义(P＞0.05);电镜下C、D组肠黏膜上皮细胞损伤较B组明显减轻,细胞间紧密连接较清楚.结论 脓毒症时肠黏膜损伤严重,EP早期与延迟干预治疗能有效保护肠黏膜屏障,提高5 d生存率,具有抗脓毒症作用 .

Effects of ethyl pyruvate on barrier function of intestinal mucosa in septic rats

Objective　To observe the effects of ethyl pyruvate (EP) on the survival rate and the intestinal mucosa barrier in septic rats. Methods①Effect of EP on the survival rate of septic rats:one hundred SPF-grade male Sprague-Dawley rats were randomly divided into 4 groups : sham group(group A), sepsis group(group B),early treatment with EP group(group C) and delayed treatment with EP group(group D). A cecum ligation and puncture procedure was used to make sepsis model. Drugs were injected intraperitoneally at 6,12,18,24,36,48,60 and 72 hours after operation. Sham group and sepsis group were administrated with 3ml ringer lactate solution(RLS),whereas early treatment group(6 h after CLP) and delayed treatment group(12 h after CLP) were treated with ringer ethyl pyruvate solution(REPS) 3 mL (EP 40 mg/kg body weight). The survival period of rats was observed within 5 days after operation. ②Effect of EP on the intestinal mucosa barrier in septic rats.: Eighty SPF-grade male Sprague-Dawley rats were randomly divided into 4 groups. Grouping and administration methods were were the same as above.Ten rats from each group were sacrificed 24 and 48 hours after operation. Concentration of D-lactate and activity of DAO in plasma were measured at each phase points and ultrastructure of the intestinal mucosa were observed under electron microscopy 48 hours after operation. Kaplan-Meier test was used for comparing survival. Data were analyzed for significance by one-way ANOVA including SNK-q test. Two-tailed tests of significance were employed and significance was assumed at P<0.05. Results　Five day survival rate of group A,B,C and D was 100%,24%, 68%、56% respectively.Compared with group B, 5-day survival rate of rats in group C and D was significantly improved (P<0.05), but no significant differences were found between group C and D (P>0.05). In group C and D, the concentration of D-lactate in plasma was significant lower than that in group B 24 and 48 hours after CLP (P<0.01). The activity of DAO in plasma of group C and D was significant lower than that in group B 24 and 48 hours after CLP (P<0.01). No significant differences in D-lactate concentration and DAO activity were found between group C and D 24 and 48 hours after CLP (P>0.05).Compared with group B, the injury of intestinal epithelial cells in group C and D was significantly reduced, and the tight junctions between epithelial cells were more clearly. Conclusion　Intestinal mucosal were injuried severely in sepsis group. Early and delayed treatment with EP can protect the intestinal mucosa barrier and improve 5-day survival rates of rat effectively, so ethyl pyruvate has well anti-septic effect.