摘要目的 观察ω-3多不饱和脂肪酸(PUFA)对严重烧伤大鼠早期肠黏膜损伤的影响,并探讨其机制. 方法 取120只SD大鼠,按随机数字表法分为假伤组、单纯烧伤组和ω-3 PUFA组,每组40只.假伤组大鼠仅模拟烫伤过程.单纯烧伤组和ω-3 PUFA组大鼠背部造成30％ TBSAⅢ度烫伤(下称烧伤).伤后5 min,假伤组和单纯烧伤组大鼠按1 mL/kg经尾静脉注射生理盐水,ω-3PUFA组大鼠通过同样的方式按1 mL/kg注射ω-3 PUFA溶液.伤后3、6、12、24、48 h,3组分别取8只大鼠,收集腹主动脉血及肠黏膜,分光光度法检测血清二胺氧化酶(DAO)含量,ELISA法检测血清TNF-α、IL-6含量,蛋白质印迹法检测肠黏膜NF-κB-p65蛋白表达.对数据行析因设计方差分析、单因素方差分析、x 2检验、LSD检验及Bonferroni校正. 结果 (1)伤后各时相点,单纯烧伤组与ω-3PUFA组大鼠血清DAO含量明显高于假伤组(P值均小于0.01),ω-3 PUFA组大鼠血清DAO含量明显低于单纯烧伤组(P值均小于0.01).(2)单纯烧伤组与ω-3 PUFA组大鼠伤后各时相点血清TNF-α、IL-6含量均明显高于假伤组(P值均小于0.01),ω-3 PUFA组大鼠伤后各时相点血清TNF-α、IL-6含量均明显低于单纯烧伤组(P值均小于0.01).(3)单纯烧伤组与ω-3 PUFA组大鼠伤后各时相点肠黏膜NF-κB-p65蛋白表达量明显高于假伤组(P值均小于0.01).伤后3、6、12、24、48 h,ω-3PUFA组大鼠肠黏膜NF-κB-p65蛋白表达量分别为1.398±0.016、1.999±0.948、2.803±0.065、1.739±0.602、1.484±0.645,明显低于单纯烧伤组的2.096±0.113、3.402±0.189、4.183±0.558、3.618 ±0.408、2.614 ±0.775,P值均小于0.01. 结论 ω-3 PUFA可能是通过降低烧伤后肠黏膜NF-κB-p65蛋白表达及血清DAO、TNF-α、IL-6含量,抑制机体炎症反应,从而减轻严重烧伤大鼠肠黏膜损伤.

abstractsObjective To observe the effects of ω-3 polyunsaturated fatty acids (PUFA) on damage of intestinal mucosa of rats with severe burn in early stage and to explore the mechanism.Methods One hundred and twenty SD rats were divided into sham injury group,pure burn group,and ω-3 PUFA group ac cording to the random number table,with 40 rats in each group.Rats in sham injury group were sham injured,while rats in pure burn group and ω-3 PUFA group were inflicted with 30％ total body surface area full-thickness scald (hereinafter referred to as burn) on the back.Rats in sham injury group and pure burn group were injected with normal saline solution (1 mL/kg) by tail vein,while rats in ω-3 PUFA group were injected with ω-3 PUFA solution (1 mL/kg) by the same way at 5 minutes post injury.At post injury hour (PIH) 3,6,12,24,and 48,abdominal aorta blood and intestinal mucosa were collected from 8 rats in each group,respectively.Serum content of diamine oxidase (DAO) was detected by spectrophotography.Serum content of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) was determined by enzymelinked immunosorbent assay.Protein expression of NF-κB-p65 in intestinal mucosa was determined by Western blotting.Data were processed with analysis of variance of factorial design,one-way analysis of variance,chi-square test,LSD test,and Bonferroni correction.Results (1) At all time points post injury,serum content of DAO of rats in pure burn group and ω-3 PUFA group was significantly higher than that in sham in jury group (with P values below 0.01),and serum content of DAO of rats in ω-3 PUFA group was significantly lower than that in pure burn group (with P values below 0.01).(2) At all time points post injury,serum content of TNF-α and IL-6 of rats in pure burn group and ω-3 PUFA group was significantly higher than that in sham injury group (with P values below 0.01),and serum content of TNF-α and IL-6 of rats in ω-3 PUFA group was obviously lower than that in pure burn group (with P values below 0.01).(3) At all time points post injury,protein expressions of NF-κB-p65 in intestinal mueosa of rats in pure burn group and ω-3 PUFA group were significantly higher than those in sham injury group (with P values below 0.01).At PIH 3,6,12,24,and 48,protein expressions of NF-κB-p65 in intestinal mucosa of rats in ω-3 PUFA group were 1.398 ±0.016,1.999 ±0.948,2.803 ±0.065,1.739 ±0.602,and 1.484 ±0.645,obviously lower than 2.096 ±0.113,3.402 ±0.189,4.183 ±0.558,3.618 ±0.408,and 2.614 ±0.775 in pure burn group (with P values below 0.01).Conclusions The ω-3 PUFA may alleviate intestinal mucosa injury of rats with severe burn in early stage through reducing protein expression of NF-κB-p65 of intestinal mucosa,serum content of DAO,TNF-α,and IL-6,and inhibiting inflammatory response.