乳铁蛋白对新生SD大鼠T细胞及肠道黏膜发育的影响

目的 研究乳铁蛋白对新生SD大鼠T细胞及肠道黏膜发育的影响.方法 将96只新生SD大鼠随机分为12组,每组8只,分别给予1.0(Ⅰ剂量组)、3.0(Ⅱ剂量组)、5.0 g·kg-1·d-1(Ⅲ剂量组)乳铁蛋白和2、3、4周喂养,并设相应对照.分别于喂养第2、3、4周处死相应喂养剂量组大鼠,采用免疫荧光法测定大鼠静脉血CD4+T和CD8+T淋巴细胞水平;取大鼠空肠及回肠各1 cm制作病理切片,采用图像分析系统观测肠道绒毛高度、周长、面积和隐窝深度.结果 喂养2周时,Ⅰ、Ⅱ剂量组大鼠的CD4+T淋巴细胞水平明显高于对照组(P均＜0.05),Ⅱ、Ⅲ剂量组大鼠的CD8+T淋巴细胞水平明显高于对照组(P均＜0.05);空肠绒毛高度、周长、面积及隐窝深度在各剂量组与对照组间总的差异无统计学意义(P均＞0.05);回肠绒毛高度、隐窝深度、绒毛周长及面积在各剂量组与对照组间总的差异有统计学意义(P均＜0.05).喂养3周时,3个剂量组大鼠的CD4+T淋巴细胞水平均明显高于对照组(P均＜0.05),Ⅲ剂量组大鼠的CD8+T淋巴细胞水平明显高于对照组(P＜0.05);空肠及回肠绒毛高度、隐窝深度、绒毛周长及面积在各剂量组与对照组间总的差异均有统计学意义(P均＜0.05).喂养4周时,3个剂量组大鼠的CD4+T淋巴细胞水平均明显高于对照组(P均＜0.05),Ⅱ、Ⅲ剂量组大鼠的CD8+T淋巴细胞水平明显高于对照组(P均＜0.05);回肠绒毛面积各剂量组与对照组间总的差异无统计学意义(P＞0.05);空、回肠绒毛高度、隐窝深度、绒毛周长及空肠绒毛面积各剂量组与对照组间总的差异均有统计学意义(P均＜0.05).结论 乳铁蛋白对新生大鼠CD4+和CD8+T淋巴细胞及空、回肠黏膜发育有促进作用,其作用受乳铁蛋白喂养剂量及时间的影响.

Abstract：

Objective To explore the effects of lactoferrin on T cells ( the levels of CD4 + T and CD8 +T lymphocytes) and the development of intestinal mucous membrane (villus heights, crypt depths, villus circumferences, and villus areas) in neonatal SD rats. Methods Totally 96 neonatal (one week old) SD rats were equally and randomly divided into twelve groups, in which animals were fed with lactoferrin at a dose of 1.0 g/( kg · d) (dose Ⅰ group), 3.0 g/(kg · d) (dose Ⅱ group), or 5.0 g/(kg · d) (dose Ⅲ group) for 2, 3, or4 weeks,with corresponding blank control groups. Rats in the dosage groups were killed at the set time points and the levels of venous blood CD4 + and CD8 + T lymphocytes were detected using immunofluorescence method. Jejunum ( 1 cm)and ileum (1 cm) specimens were obtained for pathological sectioning, and the villus height, crypt depth, villus circumferences, and villus areas were measured through image analysis system. Results The CD4 + T lymphocyte levels at two weeks were significantly different among dose I group, dose Ⅱ group, and control groups ( all P ＜0. 05).The CD8 + T lymphocyte levels at two weeks were significantly different among dose Ⅱ group, dose Ⅲ group,and control groups ( all P ＜ 0. 05 ). The villus heights, crypt depths, villus circumferences, and villus areas of jejunum at two weeks between feeding groups and control groups were not significantly different ( all P ＞ 0. 05 ), while the condition in ileum was on the contrary. The CD4 + T lymphocyte levels at three weeks were significantly different between feeding groups and control groups ( P ＜ 0. 05 ). The CD8 + T lymphocyte levels at three weeks between dose Ⅲ group and control groups were significantly different ( P ＜ 0. 05 ). The villus heights, crypt depths, villus circumferences, and villus areas of jejunum and ileum at three weeks were significantly different between feeding groups and control groups ( all P ＜ 0. 05 ). The CD4 + T lymphocyte levels at four weeks between feeding groups and control groups were significantly different (P ＜0. 05). The CD8 + T lymphocyte levels at four weeks were significantly different among dose Ⅱ group, dose Ⅲ group, and control groups ( all P ＜ 0. 05 ). Except villus areas of ileum, the villus heights, crypt depths, villus circumferences of jejunum and ileum, and villus areas of jejunum at four weeks were significantly different between feeding groups and control groups ( all P ＜ 0.05 ). Conclusions Lactoferrin can promote the levels of CD4 + and CD8 + T lymphocytes in venous blood and facilitate the development of the mucous membranes of jejunum and ileum. However, such effects are affected by the dose and timing of lactoferrin feeding.

Effects of lactoferrin on T cell and the development of intestinal mucous membrane in neonatal SD rat

Objective To explore the effects of lactoferrin on T cells ( the levels of CD4 + T and CD8 +T lymphocytes) and the development of intestinal mucous membrane (villus heights, crypt depths, villus circumferences, and villus areas) in neonatal SD rats. Methods Totally 96 neonatal (one week old) SD rats were equally and randomly divided into twelve groups, in which animals were fed with lactoferrin at a dose of 1.0 g/( kg · d) (dose Ⅰ group), 3.0 g/(kg · d) (dose Ⅱ group), or 5.0 g/(kg · d) (dose Ⅲ group) for 2, 3, or4 weeks,with corresponding blank control groups. Rats in the dosage groups were killed at the set time points and the levels of venous blood CD4 + and CD8 + T lymphocytes were detected using immunofluorescence method. Jejunum ( 1 cm)and ileum (1 cm) specimens were obtained for pathological sectioning, and the villus height, crypt depth, villus circumferences, and villus areas were measured through image analysis system. Results The CD4 + T lymphocyte levels at two weeks were significantly different among dose I group, dose Ⅱ group, and control groups ( all P ＜0. 05).The CD8 + T lymphocyte levels at two weeks were significantly different among dose Ⅱ group, dose Ⅲ group,and control groups ( all P ＜ 0. 05 ). The villus heights, crypt depths, villus circumferences, and villus areas of jejunum at two weeks between feeding groups and control groups were not significantly different ( all P ＞ 0. 05 ), while the condition in ileum was on the contrary. The CD4 + T lymphocyte levels at three weeks were significantly different between feeding groups and control groups ( P ＜ 0. 05 ). The CD8 + T lymphocyte levels at three weeks between dose Ⅲ group and control groups were significantly different ( P ＜ 0. 05 ). The villus heights, crypt depths, villus circumferences, and villus areas of jejunum and ileum at three weeks were significantly different between feeding groups and control groups ( all P ＜ 0. 05 ). The CD4 + T lymphocyte levels at four weeks between feeding groups and control groups were significantly different (P ＜0. 05). The CD8 + T lymphocyte levels at four weeks were significantly different among dose Ⅱ group, dose Ⅲ group, and control groups ( all P ＜ 0. 05 ). Except villus areas of ileum, the villus heights, crypt depths, villus circumferences of jejunum and ileum, and villus areas of jejunum at four weeks were significantly different between feeding groups and control groups ( all P ＜ 0.05 ). Conclusions Lactoferrin can promote the levels of CD4 + and CD8 + T lymphocytes in venous blood and facilitate the development of the mucous membranes of jejunum and ileum. However, such effects are affected by the dose and timing of lactoferrin feeding.