Effects of Sodium hydroxybutyrate on expression of hippocampal N-methyl-D-aspartate receptor 1 subunit mRNA in neonatal rat with hypoxic- ischemic insult

Abstract

Objective To investigate the effect of sodium hydroxybutyrate(GHB) on expression of hippocampal N-methyl-D-aspartate receptor 1 subunit (NR1) mRNA in the neonatal rat with hypoxic-ischemic insult. Methods One hundred eighty seven-day(7d) old Sprague Dawley rat pups of either sex weighting 10 g～14 g were randomly assigned to sham group(S), normal saline group(C),GHB 50 mg/kg group(γ50),GHB 100 mg/kg group(γ100)and GHB 200 mg/kg group(γ200),n=6.The procedure for the induction of hypoxia-ischemia was done according to the way described by Rice:under ether anesthesia,pups were subjected to left carotid artery ligated followed by 2 h of hypoxic exposure(O2:N2=8﹪:92﹪).The pups in S group were only aparted left carotid artery which was not obturated and no hypoxia.GHB 50 mg/kg, 100 mg/kg, 200 mg/kg was administered i.p immediately after hypoxia,then a time every 8h inγ50、γ100 and γ200 group respectively.The same volume normal saline was administered i.p in the same way in S and C group.Reverse transcriptase polymerase chain reaction(RT-PCR) was used to analyze the expression of NR1 mRNA semi-quantificationally in the left hippocampus at 2 h、6 h、12 h、1 d、3 d、7 d after insult in S、C、γ50、γ100 and γ200 group. Results The difference of expression of NR1 mRNA between S and C group wasn't significant.At any time after insult, The differences of expression of NR1 mRNA among C and three GHB group were not significant too. Conclusion Hypoxia-ischemia and GHB didn't significantly affect the expression of NR1 mRNA in neonatal rat hippocampus.