精氨酸强化全肠外营养对小肠上皮细胞增殖与凋亡的影响

Effects of arginine-enriched TPN on proliferation and apoptosis of intestinal epithelial cells

目的:探讨精氨酸强化的全肠外营养(TPN)对小肠上皮细胞增殖与凋亡的影响。方法:将24只幼兔分为正常对照组、标准TPN组、精氨酸强化TPN组(精氨酸的供热量占总热量的2%)。7 d后,分别取血和回肠组织进行以下检测:①肠黏膜形态学;②肠道细菌移位率;③血浆D-乳酸含量;④肠上皮增殖细胞核抗原(PCNA);⑤肠上皮细胞凋亡。结果:①标准TPN组肠黏膜明显变薄、萎缩(P<0.01),而精氨酸强化TPN组肠黏膜的萎缩较标准TPN组明显减轻(P<0.05)。②精氨酸强化TPN组肠道细菌移位率较标准TPN组显著降低(P<0.05)。③精氨酸强化TPN组血浆D-乳酸含量较标准TPN组明显降低(P<0.01),但较正常对照组仍偏高(P<0.05)。④精氨酸强化TPN组PCNA阳性率较标准TPN组明显增高(P<0.01),但仍低于正常对照组(P<0.05)。⑤精氨酸强化TPN组的凋亡指数显著低于标准TPN组(P<0.01)。结论:精氨酸能维持肠黏膜形态和功能的完整性,促进肠上皮细胞增殖和抑制其凋亡。

Objective： To investigate the effects of arginine enriched TPN on proliferation and apoptosis of intestinal epithelial cells. Methods：24 young rabbits were divided into 3 groups： control group, standard TPN group and arginine-enriched TPN group. Rabbits in the control group received free chow and water ad libitum after ligation of the fight jugular vein; animals in the other two groups received standard TPN （175kcal/kg · d, 200 ml/kg · d） or arginine enriched （2% of total energy） TPN. After 7 days of TPN administration, plasma and ileum were collected for the following tests ： （1）intestinal morphological changes; （2）incidence of bacterial translocation; （3）D-lactic acid level in plasma; （4）expression of proliferating cell nuclear antigen （PCNA） of epithelial cells ; （5）apoptosis of epithelial cells. Results ：（1）The mucosal thickness, villus height and villus surface area in argnine enriched TPN group were significantly higher than those in standard TPN group （P 〈 0.05） and had no significant differences in comparison with those in control group （ P 〉 0.05 ）. （2）The incidence of bacterial translocation in arginine enriched TPN group was significantly lower than that in standard TPN group （P 〈 0.05 ） and had no significant differences in comparison with that in control group （P 〉 0.05 ）. （3）The plasma D-lactic acid level in arginine enriched TPN group was significantly lower than that in standard TPN group （P 〈 0.01 ） but still higher than that in control group （P 〈 0.05 ）. （4）The positive rate of PCNA expression in arginine enriched TPN group was significantly higher than that in standard TPN group （P 〈 0.01 ） but still lower than that in control group （P 〈 0.05）. （5）The apoptosis index in arginine enriched TPN group was significantly lower than that in standard TPN group （P 〈 0.01 ） and had no significant differences in comparison with that in control group （ P 〉 0.05 ）. Conclusion ： Arginine plays an important role in maintaining the integrity of gut barrier, reducing the apoptosis of epithelial cells and improving the intestinal cells proliferation.