早期肠内免疫营养对烫伤小鼠肠道免疫功能的影响

目的 了解早期免疫强化肠内营养对烫伤小鼠肠道免疫功能的影响.方法 选择24只雄性BALB/c小鼠制作20%TBSAⅢ度烫伤模型,采用简单随机法分成2组.每组12只.普通营养组:于伤后2 h开始经口灌喂普通肠内营养剂;免疫营养组:方法同前,在普通营养剂基础上加入谷氨酰胺和精氨酸.2组营养剂糖、脂肪、蛋白质供热比均为82:3:15,热量与氮之比为150:1.每只小鼠营养摄入按732.2 kJ·kg-1·d-1计算,第1天摄入标准量的1/3,第2天摄入标准量的1/2,第3天起摄入全量,每天的计划量分4～6次喂完.2组营养摄入为等氮、等热量、等体积.小鼠连续灌喂7d后处死,取全段小肠.另取10只同品系小鼠作为健康对照组,同法取材.记录肠集合淋巴结细胞总数,通过流式细胞仪检测淋巴结中CD3+、CD4+、CD19+及凋亡细胞变化,双抗体夹心酶联免疫吸附测定法检测肠IgA变化.结果 健康对照组、普通营养组、免疫营养组小鼠肠道淋巴结细胞总数分别为(4.5±0.6)×106、(2.3±0.4)×106、(3.8±0.5)×106个,与健康对照组比较,后2组细胞数明显减少(P＜0.05).但免疫营养组高于普通营养组(P＜0.05);3组小鼠肠道淋巴结CD3+、CD4+、CD19+细胞数比较情况类似于淋巴结细胞总数.健康对照组、普通营养组、免疫营养组淋巴细胞凋亡率分别为(4.8±2.1)%、(12.7±2.4)%、(8.0±1.7)%,与健康对照组比较,后2组小鼠细胞凋亡率明显增加(P＜0.05),但免疫营养组低于普通营养组(P＜0.05).健康对照组、普通营养组、免疫营养组肠IgA水平分别为(42±7)、(35±6)、(38±6)μg/cm,与健康对照组相比,后2组水平明显减低(P＜0.05),但免疫营养组高于普通营养组(P＜0.05).结论 用强化免疫营养剂进行早期肠内营养,可以改善烫伤小鼠肠道免疫功能.

Effect of early enteral immune nutrition on immune function of intestine in mice with severe burn

Objective To investigate the effects of early enteral nutrition supplemented with im-mune nutrient on intestine immune function in mice with severe burn. Methods Twenty-four BALB/c mice were inflicted with 20% TBSA full-thickness scald, then they were randomly divided into EN( with oral administration of common enteral nutrition after 2 hours) and EIN( with oral administration of common enter-al nutrition and glutamine, arginine after 2 hours)groups. Another 10 mice were used as the normal control (NC) group. The supplied energy ratio( carbohydrate: fat: protein)in former 2 groups was 82:3 : 15, and the ratio of energy to nitrogen was 150: 1. The energy requirement of each mouse was calculated according to 732.2jJ·kg-1·d-1,one third of the requirenment was administrated on 1st day,and one half of it on 2nd day, and full energy requirement was started on the 3rd day,and the requirement was divided into 4-6 por-tions every day. The feed was isoealoric, isonitrogenous, and isovolumic for the 2 experimental groups. All mice were sacrificed and entire small intestine was harvested for determination of intestinal IgA level by ELISA, total Peyer's patches (PP) lymphocytes and their apoptosis ratio, and changes in PP lymphocytes ( CD3 + ,CD4+ ,CD19 + ) on 7th day of the experiment. Results Compared with those in NC group (4.5± 0.6) x 106, (42 ± 7 )μg/em , respectively ], total PP lymphocytes and intestinal IgA levels in EN and EIN groups obviously decreased(2.3 ±0.4) ×106, (35±6)μg/cm,(3.8±0.5) × 106, (38±6)μg/cm, re-spcctively, P <0.05], among which the values in EIN group were higher than EN group( P <0.05). The changes in PP lymphocytes were similar to that of total PP lymphocytes. Compared with that in NC group (4.8 ±2.1 ) % ] , the apoptosis ratio of PP lymphoeytes in EN and E1N groups significantly increased ( 12.7 ± 2.4 ) % , ( 8.0 ± 1. 7 ) %, respectively, P < 0.05 ], however the ratio in EIN group was lower than that of EN group( P < 0.05). Conclusions Early enteral nutrition supplemented with immune nutrient can improve intestinal immune function in mice with severe burn.