0～6月母乳中的抗感染因子

本文用单向琼脂免疫扩散法测定了分娩后第1天到产后6个月301份母乳中SIgA,IgM,IgG,补体C_3、C_4,乳铁蛋白和溶菌酶。在母乳SIgA,IgM和IgG三种主要的免疫球蛋白中,以SIgA的含量最高,占初乳中免疫球蛋白总量的89.8％;产后第1天母乳中SIgA高达3152.5±758.4mg/dl,是正常人血清中IgA含量的13.5倍。新生儿喂以母乳对保护消化道粘膜,避免感染有重要意义。产后第1天初乳中补体C_3为99.7±40.0mg/dl,补体C_4为65.9±23.5mg/dl,接近正常人血清水平。乳铁蛋白在初乳中含量极高,产后第1天高达1228.7±351.0mg/dl。溶菌酶在产后第1天的母乳中含量高达944.2±335.3μg/ml,是新鲜牛奶中溶菌酶含量的429倍。将母乳加热62.5℃30分钟,SIgA损失29.7％,溶菌酶损失8.3％,为了保留母乳中的抗感染因子,贮存人乳的消毒以巴斯德灭菌法最好。

ANTI-INFECTIVE FACTORS OF BREAST MILK DURING THE FIRST SIX MONTHS OF LACTATION

Human colostrum and milk collected at different times during the first six months of lactation from 301 subjects were tested for the levels of SIgA, IgM, IgG, C3, C4, lactoferrin and lysozyme by the technique of radial immunodiffusion. These kinds of immunoglobulins in colostrum and milk were detected, however the SIgA was highest among immunoglobulins in colostrum, which acounted for 89.8%.The average level of SigA on the first day of postpartum was 3152.5 mg/dl and exceeded those in the serum by 13-fold. It was suggested that breast-feeding may be crucial for the newborns before their mucosal immune system has been established. The average levels of C3 and C4 on the first day of postpartum were 99.7mg/dl and 65.9mg/dl respectively, reaching the normal serum level. Lactoferrin was as high as 1228.7mg/dl in the colostrum of the first day of lactation. The concentration of lysozyme was 944.2ug/ml on the first day of postpartum, which was about 429 times higher than that of cow milk. Using Holder pasteurization (62.5℃, 30 minutes), the SIgA and lysozyme activity of the milk could be reduced by 29.7% and 8.3% respectively, but a lot of anti-infective factors still remained in milk. So pasteurization may be useful for the sterilization of stored human milk.