乳凝集素对新生仔兔小肠粘膜及小肠CD4~+,CD8~+,CD25~+淋巴细胞发育的影响

目的探讨乳凝集素(lactadherin)对新生仔兔在吮乳期及断奶期小肠粘膜发育以及小肠淋巴细胞发育的影响。方法新生仔兔共45只,随机分为母乳组(GB),配方奶组(GF)及配方奶加乳凝集素组(GL,100μg/ml),每组15只,在3w和5w应用图像分析技术检测新生仔兔小肠粘膜发育情况,分别在1、2、3、4和5w时,应用流式细胞技术测定小肠CD4+,CD8+,CD25+淋巴细胞发育情况。结果(1)GL组3w空肠绒毛周长、绒毛面积、绒毛高度及隐窝深度均超过GF组,GB组3w空肠绒毛周长及绒毛高度超过GF组;GL组5w空肠和回肠绒毛周长、绒毛面积、绒毛高度及隐窝深度均超过GF组和GB组。(2)5w各组小肠绒毛发生变化,绒毛表面由高密度的手指状变为平滑叶状或舌状,GL组绒毛面积和高度恢复较GB和GF组好。(3)GL组回肠CD4+淋巴细胞发育较GF组好,GB组较GL组好;GL组回肠CD25+淋巴细胞发育较GF组好(P<0.05)。结论乳凝集素对近端空肠粘膜形态发育和小肠CD4+和CD25+淋巴细胞发育有促进作用,并且可能帮助断奶期绒毛的恢复。

EFFECT OF LACTADHERIN ON DEVELOPMENT OF MUCOSA AND LYMPHOCYTES OF SMALL INTESTINE IN NEONATAL RABBITS

Objective:To study the effect of lactaderin on the development of mucosa and lymphocytes of small intestine during the sucking and weaning period in neonatal rabbits. Method:Forty-five neonatal rabbits were randomly divided into breast milk-fed group (GB), formula-fed group (GF) and formula-fed group supplemented with lactadherin function peptide (GL,100 μg/ml) and 15 for each group. During 3 w and 5 w, the development of small intestinal mucosa using morphometric analysis was studied; and during 1,2,3,4 and 5 w, the development of CD4+, CD8+, CD25+ lymphocytes was measured by flow cytometry. Results:(1) At 3 w, the villa circumferences, areas, heights and crypt depths in the jejunum were higher in GL than GF, while villa circumferences and heights were higher in GB than GF. At 5 w villa circumferences, areas, heights and crypt depths in the ileum were higher in GL than GB and GF. (2) The morphologies of villa at 5 w changed from narrow finger to smooth lobiform or tongue like, and the recovery of villa areas and heights were better in GL than GB and GF .(3) The development of CD4+ lymphocytes in ileum was greater in GL than GF, and GB than GL. CD25+ lymphocytes in ileum was greater in GL than GF. Conclusion:Lactadherin may stimulate themorphological development of proximal jejunum and the development of CD4+ and CD25+ lymphocytes in small intestine. Moreover it can help recovery of villa during the weaning period.