Wang Fengjun, Wang Shiliang, Zhao Yun, You Zhongyi, Wang Pei, Vallete A
Institute of Burn Research, Southwestern Hospital, Third Military Medical University. Chongqing 400038 P.R. China.
Zhonghua Shao Shang Za Zhi. 2002 Aug;18(4):203-6.
To explore the influence of different nutritional support routes on the intestinal mucosal epithelial cell cycle in burned rats.
Sixty-six Wistar rats inflicted with 30% TBSA III degree burns on the back were employed as the model and were randomly divided into enteral feeding group (EF) and intravenously parenteral nutrition group (PN). Equal volume of nutritional support fluid containing predetermined equal amount of calories and nitrogen was applied via feeding or intravenously infusion through external jugular vein. The indices were observed on 6, 12, 24, 48 and 72 postburn hours (PBHs) with the reference to those in 6 normal rats. The intestinal epithelial cell cycle in jejunal and ileal mucous membrane was analyzed by flow cytometry. Western blotting method was employed in the examination of the expression of cyclin D1, E and that of cyclin dependent kinase (CDK)2 and CDK4.
(1) lntestinal mucosal epithelial G0/G1 ratio in jejunum in EF group was significantly lower than that in PN group at 72 PBHs (P < 0.05). While the ratio in ileum in EF was obviously higher than that in PN groups at 6, 12, 48 and 72 PBHs (P < 0.05). (2) The cell percentage of S phase in EF group was evidently higher than that in PN group (P < 0.05 - 0.01) at 48 and 72 PBHs. (3) Intestinal mucosal cyclin D1 expression increased significantly in EF group at 24 PBHs and in PN group at 48 PBHs (P < 0.05) and which in EF group was obviously higher than that in PN group at 72 PBHs (P < 0.05). (4) The expression of the intestinal mucosal cyclin E in EF group at 72 PBHs was evidently higher than the control value and that in PN group (P < 0.05). (5) The expression of CDK2 exhibited no obvious difference among PN,EF and control group (P < 0.05). The CDK4 expression in EF group increased obviously at 72 PBHs (P < 0.05).
Early postburn enteral feeding was beneficial to the progression of intestinal mucosal epithelial cell cycle and to the repairing and renovation of injured intestinal mucosal membrane. Cyclin and CDK might be important in the modulation of the intestinal mucosal epithelial cell cycle.
探讨不同营养支持途径对烧伤大鼠肠黏膜上皮细胞周期的影响。
选取66只背部30%体表面积Ⅲ度烧伤的Wistar大鼠作为模型,随机分为肠内营养组(EF)和静脉肠外营养组(PN)。通过经口喂养或经颈外静脉静脉输注给予等体积含预定等量热量和氮的营养支持液。于烧伤后6、12、24、48和72小时观察各项指标,并与6只正常大鼠的指标作对照。采用流式细胞术分析空肠和回肠黏膜的肠上皮细胞周期。采用蛋白质免疫印迹法检测细胞周期蛋白D1、E及细胞周期蛋白依赖性激酶(CDK)2和CDK4的表达。
(1)烧伤后72小时,EF组空肠肠黏膜上皮G0/G1期比例显著低于PN组(P<0.05)。而在烧伤后6、12、48和72小时,EF组回肠该比例明显高于PN组(P<0.05)。(2)烧伤后48和72小时,EF组S期细胞百分比明显高于PN组(P<0.05 - 0.01)。(3)烧伤后24小时EF组和48小时PN组肠黏膜细胞周期蛋白D1表达显著增加(P<0.05),且烧伤后72小时EF组明显高于PN组(P<0.05)。(4)烧伤后72小时EF组肠黏膜细胞周期蛋白E表达明显高于对照组及PN组(P<0.05)。(5)PN组、EF组和对照组CDK2表达无明显差异(P<0.05)。烧伤后72小时EF组CDK4表达明显增加(P<0.05)。
烧伤后早期肠内营养有利于肠黏膜上皮细胞周期进程及损伤肠黏膜的修复与更新。细胞周期蛋白和细胞周期蛋白依赖性激酶可能在肠黏膜上皮细胞周期调控中起重要作用。