烧伤早期营养对大鼠降钙素基因相关肽影响的实验研究

目的观察烧伤早期不同营养途径对肠道的复苏效应,及其与降钙素基因相关肽(cal-citoningene-relatedpeptide,CGRP)的关系方法30%TBSAⅢ度烧伤Wistar大鼠,随机分为灌喂组(EF组,30只)及早期静脉营养组(EPN组,30只).此外,6只大鼠不烧伤,作对照组(C组).伤后6、12、24、48、72h观察大鼠一般情况、肠黏膜血流量、血浆CGRP免疫活性物质浓度、CGRP染色阳性物质在肠道的变化.结果烧伤后大鼠肠黏膜血流量下降,EF组下降程度明显低于EPN组(P＜0.05～0.01);烧伤后血浆CGRP升高,EF组血浆CGRP在伤后72h明显低于EPN组(P＜0.01);肠道CGRP阳性染色物质在烧伤后明显减少(P＜0.05～0.01),EF组在伤后24、48h明显多于EPN组(P＜0.05);肠黏膜血流量下降和肠肌间丛CGRP下降呈正相关(r=0.72,P＜0.05).结论肠道营养在烧伤早期肠道的复苏效应方面较静脉营养优越,伤后肠道CGRP免疫活性物质减少,血浆CGRP免疫活性物质过度增高可能是烧伤后肠道血供减少的重要机制之一,早期肠道营养可能通过调节CGRP而发挥复苏作用.

An experimental study on the effects of early postburn nutrition on calcitonin gene - related peptide

Objective To explore the resuscitation effects of different nutritional routes during early postburn stage on intestinal tract , and the relationship between calcitonin gene - related peptide (CGRP) and resuscitation of intestinal tract. Methods Sixty Wistar rats inflicted by 30% TBSA III degree flame burn were randomly divided into burn with enteral feeding guoup (EF,30 rats) and burn with early parenteral nu- trition group (EPN group, 30 rats). Six normal rats without burn injury served as control group (C ). The changes in general condition, intestinal mucosal blood flow,plasma concentration of CGRP immunologic com- petence substance and intestinal CGRP positive staining suhstance in the rats were observed at 6, 12,24,48 and 72 posthurn hours(PBHs). Results The rat intestinal mucosal blood flow decreased postburn, espe- cially in EPN group(P < 0. 05 ). The postburn plasma CGRP increased and the plasma CGRP level in EF group was obviously lower than that in EPN group at 72 PBH(P <0. 01 ). The CGRP positive staining cells of intestinal tract decreased markedly postburn(P < 0. 05 ) in both burn groups, and those in EPN were sig- nificantly lower abundant than those in EF group at 24 and 48 PBHs(P < 0. 05 ). Furthermore,the decrease in intestinal mucosal blood flow was positively related to the decrease in intestinal intramuscular nerve plexus CGRP(r = 0. 72, P < 0. 05 ). Conclusion Enteral nutrition exerted better effects on eariy postburn intes- tinal resuscitation than parenteral nutrition. The decrease in intestinal blood supply might be mainly due to the excessive increase in plasma CGRP immune active substance and the decrease of postburn intestinal tract CGRP immunologic competence substance. Early enteral feeding might play resuscitative role by modulating CGRP.