Study To Expression Of Growth Associated Protein-43in The Brain Of Intrauterine Growth Retardation Rats

Objective:This study through the pregnancy low protein diet method to set up the animal models of intrauterine growth retardation(IUGR),to observe the change of expression to growth associated protein43(GAP-43)in the brains of IUGR neonatal rats at different parts of the organization and different development stages,and analyze the role of GAP-43in the brain development and function abnormality happens mechanism on IUGR neonatal rats, provide the related theory basis to intervention and treatment for clinical.Methods:Use the method of whole pregnancy low protein diet to set up IUGR experimental animal model. According to Conception order,the rats randomly divided into low protein diet group and normal diet group.In the low protein diet group,those neonatal rats,in line with the standard of IUGR diagnosis,need be randomly selected30as the IUGR group;in the normal diet group, those neonatal rats with normal birth weight, need be randomly selected30as the the control group; then each of the two groups of experiment rats needs be randomly divided into0day,10day,30days subgroups.Two groups of experimental rats measure the weight of body and brain in the0day,10day,30day.Hematoxylin and eosin stain was performed to examine the characteristic at different development stages of experimental annimals' brains, Immunohistochemisty was performed to examine the change of the expression of GAP-43protein at different development stages in experimental annimals'cerebral cortex and hippocampus CA1area,CA3area. Fluorescence quantitative polymerase chain reaction (FQ-PCR) was performed to examine the change of the expression of GAP-43mRNA at different development stages in experimental annimals'hippocampus.Results:The IUGR incidence rate of the low protein diet group (62.5%) was significantly higher than the normal diet group (7.89%, P<0.05).The still birth rate of the low protein diet group (17.94%) was significantly higher than the normal diet group (5.0%, P<0.05).In the Oday time, The body weight of IUGR group(4.6847±0.3126g)was significantly lower than control group(6.4352±0.3135g, P<0.01);in the10day time and30day time there were have no difference between the two groups of weight(P>0.05).The brain weight of IUGR group were significantly lower than control group (P<0.01) in the Oday,10day,30day time.The levels of GAP-43protein in cerebral cortex of IUGR group were significantly lower than control group (P＜0.01) in the0day,10day time;in the30day time there were have no difference between the two groups (P>0.05).The levels of GAP-43protein in hippocampus CA1area and CA3area, in the lOday IUGR group were significantly lower than control group (P＜0.01); in the0day,30day time there were have no difference between the two groups (P>0.05).FQ-PCR relative quantitative results shown that, The levels of GAP-43mRNA in hippocampus area of neonatal rats with IUGR group were significantly lower than control group in the l0day time(P<0.01); in the0day,30day time there were have no difference between the two groups (P>0.05)Conclusions:1.The pregnancy low protein diet is a good method to set up IUGR experimental animals model.2.The development of brain weight of those neonatal rats in IUGR group is less than those in the control group in a long period.3.Neonatal rats in the IUGR group can be observed Cerebral cortex growth unusual at the Oday time, and this continues to the30day time(About human8years old). The lower expression of GAP-43in the hippocampus area may be concerned with forward learning and intelligent development of IUGR.