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醫(yī)學免費論文:添加丙氨酰谷氨酰胺胃腸外營養(yǎng)對燙傷大鼠的作用
【摘要】 目的 探討添加丙氨酰谷氨酰胺(Ala-Gln)全胃腸外營養(yǎng)(TPN)對燙傷大鼠的空腸黏膜、蛋白質代謝及創(chuàng)面肉芽組織的影響。方法 33只SD大鼠，隨機分為非燙傷正常參照組(正常組)、傳統(tǒng)TPN組(傳統(tǒng)組)和添加Ala-Gln的TPN組(二肽組)，每組各11只。正常組自由飲食，另2組大鼠在頸外靜脈插管后行30%體表面積Ⅲ度燙傷，并接受等熱量(780 kJ·kg-1·d-1)等氮量(1.8 g氮量·kg-1·d-1)TPN 7天，留取24 h尿測每日氮平衡和累積氮平衡;7天后取血測定總蛋白(TP)、白蛋白(ALB)、前白蛋白(PAB)、轉鐵蛋白(TRF)，高效液相法檢測肌肉中谷氨酰胺(Gln)的含量;取一段空腸作黏膜形態(tài)學觀察;光鏡下觀察燙傷創(chuàng)面肉芽組織的情況。結果 二肽組的血清PAB、TRF及肌肉中Gln含量明顯高于傳統(tǒng)組(P<0.01)，空腸黏膜絨毛高度、隱窩深度、黏膜厚度、絨毛表面積明顯高于傳統(tǒng)組(P<0.01)，創(chuàng)面肉芽組織中的毛細血管和成纖維細胞密度明顯高于傳統(tǒng)組(P<0.01)。結論 燙傷大鼠應用添加Ala-Gln的胃腸外營養(yǎng)能改善機體氮平衡，促進機體蛋白質合成，減少肌肉中Gln含量的下降，減輕空腸黏膜的萎縮，促進燙傷創(chuàng)面的肉芽增殖愈合。
【關鍵詞】 丙氨酰谷氨酰胺;胃腸外營養(yǎng)，全;小腸黏膜;代謝;肉芽組織;燒傷;大鼠
Effect of alanyl-glutamine-supplemented total parenteral nutrition on intestinal mucosa, protein metabolism and granulation tissues of the burn wounds in scalded rats
SANG Jianfeng，WU Wenxi，XU Qin，HUA Yibing，DING Qiang，ZHOU Shougui醫(yī).學全.在.線網站bhskgw.cn
1. Department of Genenral Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing,
Jiangsu 210008, China; 2. Department of Gastrointestinal Surgery, The First Affiliated Hospital of Nanjing
Medical University, Nanjing, Jiangsu 210029; 3. Department of Burn Surgery, The First Affiliated Hospital of Nanjing Medical University
Abstract： Objective To evaluate the effect of alanyl-glutamine (Ala-Gln)-supplemented total parenteral nutrition (TPN) on the intestinal mucosa, protein metabolism and granulation tissues of the wounds in scalded rats. Methods 33 SD rats were randomly divided into three groups (n=11): control group, conventional TPN group (convention group) and Ala-Gln supplemented TPN group (Ala-Gln group). The control group received standard diet, while the two TPN groups having been placed a central venous catheter and subjected to 30% TBSA III0 burn received isocaloric (780kJ·kg-1·d-1) and isonitrogenous (1.8gN·kg-1·d-1, 48% of nitrogen was supplied with Ala-Gln in Ala-Gln group) TPN for 7 days. Nitrogen balance (NB) and cumulated nitrogen balance (CNB) were monitored. At the end of TPN, serum total protein (TP), albumin (ALB), prealbumin (PAB), transferrin (TRF), Gln in muscle were monitored. Jejunal mucosal morphological changes were observed with light microscopy. The density of capillary vessels and fibroblasts in granulation tissues on wound was observed with light microscopy. Results Serum PAB, TRF, Gln level in muscle and CNB in Ala-Gln group were significantly higher than those in the convention group (P< 0.01). The jejunal villus height, crypt depth, mucosal thickness and villous surface area significantly increased in Ala-Gln group. The density of capillary vessels and fibroblasts in the granulation tissues in Ala-Gln group was significantly higher than that in the convention group (P< 0.01). Conclusion Ala-Gln supplemented TPN in scalded rats could promote protein anabolism, improve nitrogen balance, attenuate the decline in Gln in the muscles and attenuate intestinal mucosal atrophy, improve T lymphocyte immune function and promote granulation proliferation and wound healing醫(yī).學全.在.線網站bhskgw.cn.
Key words: alanyl-glutamine; parenteral nutrition, total; intestinal mucosa; metabolism; granulation; burns; rats
谷氨酰胺( Glutamine, Gln) 是一種體內含量豐富的游離氨基酸, 它是所有快速增殖細胞的能源物質，如小腸黏膜上皮細胞、淋巴細胞、腫瘤細胞等, 也被認為是應激狀態(tài)下的“條件必需氨基酸”。燙傷應激狀態(tài)下，體內蛋白質(尤其是骨骼肌蛋白質)分解和尿氮排泄增加，Gln消耗增加，血漿及組織中Gln濃度下降。補充Gln有可能改善機體氮平衡、促進機體蛋白質合成、減輕小腸黏膜的萎縮。但Gln水溶解度低，且不穩(wěn)定，在加熱滅菌時生成有毒的焦谷氨酸和氨，限制了Gln在腸外營養(yǎng)中的使用，而丙氨酰谷氨酰胺(Ala-Gln)克服了以上缺點，進入體內很快生成Gln。本實驗觀察了添加Ala-Gln的全胃腸外營養(yǎng)(TPN)對燙傷大鼠的蛋白質代謝、空腸黏膜及燙傷創(chuàng)面的肉芽組織的作用。
