Alterations of glutamate and cyclic nucleotides in neonatal rat brain after cerebral hypoxic-ischemic injury
CUI Jingbin, CHEN Zhengyao,WANG Junping, et al. Department of Biochemistry, Medical College of Zhengzhou University, Zhengzhou 450052,P.R.China
Objective To study the changes and roles of glutamate(Glu) content and cyclic nucleotide levels in neonatal rat brain after hypoxic ischemic brain damage(HIBD).Methods Neonatal Wistar rats of 7 days were divided into two groups randomly, namely control group and cerebral hypoxic ischemic group. The models of perinatal hypoxic ischemic brain injury rats were prepared by ligation of left common carotid artery combined with a temporary systemic hypoxia (inhaling 8 % O 2 and 92 % N 2). The changes of Glu concentration and cyclic nucleotide levels in neonatal rat brain were observed by microdetermination or immunoradioassay at different times after injury.Results The content of Glu increased significantly as (17.56±5.32) mol/g(P0.01), and levels of cAMP increased distinctly as (15.01±3.80) nmol/g(P0.05) at 0 minute after HIBD as compared with control group, and then declined gradually and reached their normal levels between 60 and 180 minutes after HIBD. Levels of cGMP increased distinctly as (0.88± 0.19) nmol/g at 180 minutes after HIBD(P0.05).Conclusions There are changes of Glu content and levels of cAMP and cGMP in neonatal rat brain after HIBD, which induce excitotoxicity and metabolic stress and play important roles in aggravation of brain damages.