ABSTRACT
Objective To evaluate the effects of sevoflurane on proteome in the cortices of neonatal rats.Methods Thirty neonatal rats at postnatal day 7 (6 rats each litter,5 litters in total) were randomly assigned into 2 groups (n =15 each):control group (C group) and sevoflurane group (S group).The rats were exposed to air and 1.8 ％ sevoflurane for 4 h in C and S groups,respectively.One rat from each litter was chosen in each group at the end of anesthesia and the puncture needle was inserted into the left ventricle via the chest wall.Arterial blood samples were then collected for blood gas analysis and for determination of blood glucose.One rat from each litter was sacrificed in each group at 3 and 72 h after the end of anesthesia,and their cortices were then dissected.Two-dimensional differential in-gel electrophoresis (2-D DIGE) was used to identify patterns of protein expression in cortices cross-labeled with different CyDyes.The differentially expressed proteins were analyzed by using matrixassisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS).Results Acid-base imbalance,anoxia or lycopenia were not found at 3 h after the end of anesthesia in both groups.The analysis showed there were 6 differentially expressed proteins at 3 h after the end of anesthesia in S group compared with C group.Among the 6 proteins,the expression of 4 proteins (class 2 c beta-tubulin,neuron-specific class Ⅲ beta-tubulin,CRMP-1 and CRMP-4) which belonged to cytoskeleton/neuronal growth proteins was down-regulated,the expression of 1 protein (ATP synthase beta subunit) which belonged to hydrolyses and transferases was down-regulated,and the expression of 1 protein (guanine nucleotide binding protein beta1) which belonged to signal transduction proteins was up-regulated (P ＜ 0.05).No significant changes in protein expression were identified at 72 h after 1.8％ sevoflurane anesthesia (P ＞ 0.05).Conclusion 1.8％ sevoflurane-induced 4 h anesthesia can induce short-time changes in the expression of proteins which are related to neuronal migration,differentiation,energy metabolism and signal transduction in cortices of neonatal rats,which may contribute to its neurodegenerative effects in brains of rats during the development period.
ABSTRACT
Objective To investigate the effects of isoflurane and sevoflurane at the equivalent depth of subanesthesia on neuronal proliferation and phosphorylation of extraceullar signal-regulated kinase 1/2 (ERK1/2)protein in the hippocampi of neonatal rats.Methods Seventy-two neonatal rats at postnatal day 7 were involved in this study and they were assigned randomly into isoflurane group (Iso group),sevoflurane group (Sev group) and control group (Con group).The rats in I group,S group or C group were separately exposed to 0.75％ isoflurane or 1.2％ sevoflurane (equivalent to 0.3 MAC for neonatal rats) or air for 6 h.Some rats in each group were injected intraperitoneally BrdU 100 mg/kg immediately (D0) (n =6) or 3 days after exposure (D3) (n =6),and their brains were perfusion and embedded by paraffin 24 h after BrdU injection.BrdU positive expressions in the in dentate gyrus (DG) area of hippocampus were detected by IHC staining.Besides,the fresh hippocampi of some rats each group were dissected at the end of anesthesia,caspase-3 and phospho-ERK1/2,ERK1/2 proteins expression were detected by Western blot (n =6).The other rats in each group were used to measure changes of pH and blood glucose (n =6).One way ANOVA test was used for data analysis among groups.Results BrdU-positive cells had no significant difference among group IsoD0 ((1332.43 ± 192.70)/mm2),group SevD0 ((1207.33 ±139.50)/mm2),and group ConDO ((1362.40 ± 227.90)/mm2) at D0,while which had significantly decreased by 32.6％ (P＜ 0.05) in group IsoD3 ((604.56 ± 65.77)/mm2) when compared with those in group ConD3 ((896.90 ± 78.77)/mm2) at D3.There was no significant difference between groups of SevD3 ((808.73 ± 41.27)/mm2) and ConD3.The expression of caspase-3 protein was increased by 195％ (P＜ 0.01) in Iso group while which only increased by 74％ (P ＜ 0.05) in Sev group when compared with Con group.The expression of P44 and P42 of phospho-ERK1/2 protein in the hippocami decreased by 53％ (P ＜ 0.01) and 47％ (P ＜ 0.01))seperately in Iso group when compared with Con group,while there were no significant differences between Sev group and Con group.Conclusion 0.3 MAC isoflurane,not sevoflurane inhibits neuronal proliferation in DG of hippocampi in the neonatal rats.Inhibiting ERK1/2 phosphorylation may involve in the mechanisms of that isoflurane inhibits neuronal proliferation.
ABSTRACT
Objective To investigate the effects of isoflurane and sevoflurane at the same dose on expression of Caspase-3 of primary somatosensory cortex (SI) and expression of micmmbule associated protein 1B (MAP1B)in cortical neuronsin neonatal SD rats.Methods Fifty-five neonatal SD rats at postnatal day 7 (eleven rats each litter,altogether 5 litters)were assigned randomly into control group(C group),isoflurane group (I group)and sevoflursne group(S group)in average.The rats in I group,S group or C group were exposed to 1.1% isoflurane or 1.8% sevoflurane (equivalent to 0.5MAC)or air 4h.The brain of neonatal rats were perfused and embedded by paraffin,Caspase-3 positive expression in the SI cortex of brain was detected by immunohistochemistry staining.Besides,the fresh cortex was dissected at O h in C group and at 2h,4h in I group and S group,microtubule associated protein 1 B expression was detected by West blot staining.Results Caspase-3 positive cells in the SI cortex were increased by 561.23%in I group(t=4.45,P<0.01)and 194.46% in S group(t=5.17,P<0.01)when compared with C group,and increased by 124.45% in I group(P<0.05)when compared with S group.The MAP1B protein was increased by 557.15%at 2h(t=16.54 P<0.01)and 475.21% at 4h(t=32.97,P<0.01)in I group while increased by 693.11%at 2h(t=9.45,P<0.001)and 268.15% at 4h(t=2.79,P=0.049) in S group when compared with C group.In S group,MAP1B protein at 4h reduced by 53.65%(P<0.01) when compared with that at 2h.Conclusion 0.5 MAC isoflurane can induce more apoptosis in the cortex in the neonatal rats'brain at postnatal day 7 than sevoflurane.They can both significantly promote the expression of MAP1B in the cortex to start the self-reparation.