人初乳中生长因子的研究

初乳中含有丰富的生长因子，可促进体外培养的ＮＩＨ－３Ｔ３细胞的ＤＮＡ合成，含０．５％（Ｖ／Ｖ）初乳的培养液与含５％小牛血清的培养液有相同的促进生长作用。初乳每毫克蛋白促细胞ＤＮＡ合成的能力比牛血清高３０倍。人初乳中生长活性物质较为丰富，含有两类生长因子－－初乳酸性生长因子（ＣＡＧＦ）和初乳碱性生长因子（ＣＢＧＦ）。这两种因子对尿素和盐酸稳定，其中ＣＡＧＦ不被巯基乙醇失活，而ＣＢＧＦ可被巯基乙醇失活

THE STUDY OF GROWTH FACTORS IN HUMAN COLOSTRUM

Human colostrum contains different kinds of growth factors that stimulate DNA synthesisin cultured NIH 3T3 cells.Colostrum at a concentration of 0.5%(V/V)had the same activity instimulating DNA synthesis as 5%(V/V)bovine serum,The specific activity per mg protein ofhuman colostrum in stimulating DNA synthesis was 30 times greater than that of bovine serum.The activity of growth factors in human colostrum was higher than that in human milk or bovinecolostrum,and only human colostrum contained two different kinds of growth factors.We havepruified acid growth factor(CAGF)and basic growth factor (CBGF) from human clolstrum by asequence of chromatography.CAGF was a monomer with molecular weight of about 6kDa andwas resistant to treatment with urea,HCl and mecaptoethanol.On the other hand,CBGF had amolecular weight of about 30kDa and appeared to be a heterodimer of 17.5kDa and 14kDasubunits.CBGF was resistant to treatment with urea or HCl and was inactivated bymercaptoethanol.It was considered that CAGF was EGF-like growth factor and CBGF wasPDGF-like growth factor.