Study On The Role Of Growth Factors Especially For IGF-II On Growth and Development Of Premature Infants

为探讨母体蛋白质营养状况对胎鼠生长发育的影响，对孕鼠进行低蛋白饲料喂养，测定孕鼠血浆IGF-I、II水平。低蛋白负荷组孕妇血浆IGF-I水平较对照组明显降低，而IGF-II水平与对照组无明显差异，本研究通过测定早产儿血浆及脐血IGF-II水平，探讨IGF-II对早产儿出生后生长发育的影响。新生儿脐血IGF-Ⅱ水平明显高于出生后符合出生后年龄的早产儿。在AFD（适合日期）婴儿中，IGF-II水平取决于胎龄，但SFD（小于日期）婴儿的IGF-II低于AFD婴儿。孕后一周正常生长的婴儿血浆IGF-II水平高于生长迟缓的婴儿。早产儿的生长速度和生长速率与足月时IGF-Ⅱ水平无相关性，而足月时体重和身高与血浆IGF-Ⅱ水平有相关性，提示IGF-Ⅱ通过营养状况对早产儿宫内生长有重要作用，并对早产儿出生后的生长和身高有影响。围产期IGF-I向IGF-II转化的机制有待进一步研究。

To clarify the effect of maternal protein nutritional status on fetal growth, low protein diet was loaded for the pregnant rats and plasma IGF-I,II of the mother rats were determined. Plasma IGF-I levels of low protein loaded mothers were significantly decreased compared to control the control group, but IGF-II levels were not different from those of control.Plasma IGF-II levels of premature infants and cord blood were determined to study about the effects of IGF-II on the growth of premature infants after birth. The IGF-II levels of cord blood were significantly higher than those of the premature infants after birth whose postcoceptional ages were fitted. In AFD (appropriate for date) infants, IGF-II levels were depended on gestational age, but IGF-II of SFD (small for date) infants were lower than those of AFD infants. The infants normally grown at term of postconceptional week were higher in average plasma IGF-II levels thanthe infants of growth retardation. The growth rates and the growth speeds were not corelated with the IGF-II levels at term, but the body weights and heights at term corelated with plasma IGF-II levels.These results indicate that IGF-II has the important role on the intrauterine growth through the nutritional condition and IGF-II has the role on the postnatal growth and stature of premature infants. The further studies are needed to reveal the switching mechanism from IGF-I to IGF-II during perinatal period.