Effects of lactoferrin on T cell and the development of intestinal mucous membrane in neonatal SD rat / 中华临床营养杂志

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.