蛋白质水平对大鼠子代脑发育及功能的影响

EFFECT OF DIETARY PROTEIN LEVELS ON BRAIN DEVELOPMENT AND FUNCTION IN RATS PROGENY

孕前、妊娠期及哺乳期给予雌性Ｗｉｓｔａｒ大鼠含酪蛋白分别为４０％、２０％和８％的等能量饲料，观察对子代脑发育及脑功能的影响。结果表明，２０％酪蛋白营养水平不能充分满足哺乳期幼鼠脑生长发育的需要。妊娠及哺乳期严重的营养不良对脑发育所产生的损害，断乳后即使给予蛋白质补充，也未能使脑发育得到恢复。

Thirty adult female Wistar rats were randomly allocated into 3 groups of 10 each and fed with various amounts of protein.i.e group Ⅰ(40% food weight from casein)、group Ⅱ (20%) and group Ⅲ (8%) respectively during 3 weeks before gestation to lactation.All of the progeny were fed the diet of group Ⅱ after lactation.The results showed that the average neonate body and brain weights of group Ⅲ were significant lower than those of group Ⅰ and group Ⅱ.The average brain weight of 21-day-old rat in group Ⅰ was the heavist,and heavier in group Ⅱ,and the difference among them was significant.The brain DNA and RNA contents in group Ⅲ were markedly lower than those of the other two groups as well as the protein contents.Analysis on the 21-day-old rat brain tissue showed that the numbers of cerebral cortex cell in outer granular layer and of hippocamus pyramidal cell in group Ⅲ were less than those in group Ⅰ and group Ⅱ.The escape-test results indicated that the fault-respone-rate,average number of fault and escape-time in group Ⅲ were higher than those in group Ⅰ and group Ⅱ.These results indicated that 20 percent of casein could meet the needs of rat brain development during gestation and after lactation,but was unable to meet the requirement while during lactation.Further research is needed to determine the adequate protein levels for lactating mothers and infants.