缺锌对大鼠脑发育的影响

本文通过建立大鼠缺锌（ｚｉｎｃｄｅｆｉｃｉｅｎｃｙ，ＺＤ）、常锌配对（ｐａｉｒｆｅｅｄｉｎｇ，ＰＦ）模型，从微观及宏观角度，较深入地研究缺锌对学习记忆的影响。结果表明：（１）ＺＤ组的摄食量、体重增长值、饲料效价均非常显著地低于ＰＦ组。（２）ＺＤ组脑的Ｇ０／Ｇ１．期细胞高于ＰＦ组，而Ｓ＋Ｇ２／Ｍ期细胞、细胞容积、脑细胞ＤＮＡ、ＲＮＡ含量均低于ＰＦ组（Ｐ＜０．０５或Ｐ＜０．０１）。（３）ＺＤ组脑细胞内的ｃＡＭＰ高于而ＮＯ含量低于ＰＦｊＨ（Ｐ＜０．０１）。（４）ＺＤ组血清锌和海马锌含量非常显著地低于ＰＦ组。（５）ＺＤ组全脑锌含量无显著下降，然脑铜含量较高，铁含量极低，与ＰＦ组比较有非常显著的差异。（６）ＺＤ组海马ＣＡ１区的ＬＴＰ诱出率为０。串刺激前后ＰＳ峰潜伏期和幅度无明显变化，而ＰＦ组ＬＴＰ诱出率为１００％，串刺激后ＰＳ峰潜伏期缩短，峰幅度明显增高。（７）ＺＤ组海马ＣＡ，区超微结构表现椎体细胞突触内突触小泡减少。（ｓ）ＺＤ组大鼠主动回避行为习得率为２４％，非常显著地低于ＰＦ组的６４％。

EFFECT OF ZINC DEFICIENCY ON THE BRAlNDEVELO MENT OF RATS

ffect of zinc on the function of learning and memory was investigatedin the zinc-defficient(ZD) rats and pair-feeding(PF)rats.The results sh-owed that:(1)The value of body weight gain and feed efficiency ratioin ZD group were significantly lower than those in PF group,(2)The totalcell numbers in G0/G1 phase of the brain in ZD group was significantlyhigher while the total cell number in S and G2/M phases,the cell size andthe cellular DNA and RNA contents of the brain in ZD group were signifi-cantly lower than those in PF group.(3) The celluar cAMP content of thebrain in ZD group was significantly higher while the NO content of the brainin ZD group was significantly lower than those in PF group.(4)The contentsof zinc in serum and hippocampus of ZD group were evidently lower thanthose of PF group(P<0.01).(5)There was no difference in zinc content oftotal brain between ZD and PF groups,The content of copper in ZD groupwas higher while the iron in ZD group was lower than those in PF group(P<0.01).(6)The long-term potentiations(LTP) of hippocampus CA1 areashowed that the LTP incidence was zero and the PS potential term(ms) hadno change after stimulation in ZD group as the LTP incidence was 100%andthe PS potential term was shortened but the PS amplitude was increased evi-dentlv after stimulation in PF group. (7) The observation of the ultrastruc-ture of hippocampus revealed that the synaptic vesicle in pyramidcyte decre-ased in the ZD group.(8) The AAR learning and maintaining was obviouslydecreased in ZD group(24%)which was significantly lower than that in PFgroup (64%)。