RESUMO
The concentrations of lactoferrin (LF) in colostrum during the first 8 days and mature milk during the first 4 months of postpartum were determined by electroimmunodiffusion. Meanwile a sensitive enzyme linked imm-unosorbent assay for measurements of LF in neonatal faeces were established. The results showed that human milk, especially colostrum, was rich in LF. The colostrum contained 6.88 ? 3.10mg/ml (M?SD) aad mature milk 3.18 ? 0.37mg/ml LF. LF in human milk was the highest during the first 3 days of lactation with a decline in concentration as lactation proceeds although a wide variation in concentration was noted among different individuals.LF in neonatal faeces showed significant difference in different feeding manners. LF level in the breast-fed infants was 19 times higher than that in the bottle-fed infants. The LF percentage detected in the former was 100% and the latter only 60%. The dynamic variations of LF in faeces of breast-fed infants during the first day of life were found to be relative to LF level in mother'milk.These data demonstrated the influence of high LF level in mother'milk on the concentrations of LF in breast-fed infants' intestine.Furthermore a few amounts of LF was found in meconium and its percentage detected was 35%. This suggested that the production of endogenous LF began from foetus period, but was limited during the first day of life. LF ingested by the breast-fed infants were not completely destroyed and thus may supplement the insufficiency of the endogenous LF in the newborn infants' intestinal tract.
