ABSTRACT
Objective To evaluate the effect of sevoflurane anesthesia on cognitive impairment in rats with traumatic brain injury. Methods One hundred and and twenty healthy male Wistar rats, aged 2-3 months, weighing 190-220 g, were assigned into 4 groups ( n=30 each) using a random number table method: control group ( group C) , traumatic brain injury group ( group T) , sevoflurane anesthesia group ( group S) , and traumatic brain injury plus sevoflurane anesthesia group ( group T+S) . A 40 g hammer was freely dropped onto the left parietal bone window from a height of 20 cm to establish the traumatic brain inju-ry model in T and T+S groups. Twelve days later, S and T+S groups inhaled 3％ sevoflurane for 3 h, and C and T groups inhaled pure oxygen for 3 h. On 1 day before anesthesia and 3 and 7 days after anesthesia, 10 rats in each group were randomly selected for performing Morris water maze test. Rats were sacrificed af-ter the end of Morris water maze test, and the hippocampal tissues were obtained for determination of the apoptosis rate of hippocampal neurons, cytoplasmic calcium concentration [Ca2+]i (by flow cytometry), expression of glucose-regulated protein 78 ( GRP78) and CCAAT∕enhancer-binding protein homologous pro-tein ( CHOP ) ( by immunohistochemistry ) , and expression of caspase-3 and caspase-12 ( by Western blot) . Results Compared with group C, the escape latency was significantly prolonged, the number of crossing platform was decreased, the apoptosis rate of hippocampal neurons and [ Ca2+] i were increased, and the expression of caspase-3, caspase-12, GRP78 and CHOP in hippocampal tissues was up-regulated in S, T and T+S groups ( P<0. 05) . Compared with T and S groups, the escape latency was significantly prolonged, the number of crossing platform was decreased, the apoptosis rate of hippocampal neurons and [ Ca2+] i were increased, and the expression of caspase-3, caspase-12, GRP78 and CHOP in hippocampal tissues was up-regulated in group T+S ( P<0. 05 ) . Conclusion Sevoflurane anesthesia can accentuate cognitive impairment in rats with traumatic brain injury, and the mechanism may be related to aggravating the degree of endoplasmic reticulum stress-induced calcium overload and increasing the apoptosis rate of hip-pocampal neurons.
ABSTRACT
Objective To evaluate the effects of nimodipine combined with 7.5％ hypertonic saline (HS) on sevoflurane-induced apoptosis of hippocampal neuron in aged rats.Methods Ninetysix healthy male Wistar rats aged 18 months and weighing 450-500 g were randomly assigned into 4 groups (n=24 each):group C,group N,group HS and group NHS.Group N received intraperitoneal injection of 1 mg/kg nimodipine and intravenous injection of normal saline,group HS received intravenous injection of 4 ml/kg 7.5％ HS and intraperitoneal injection of normal saline,group NHS received intraperitoneal nimodipine and intravenous HS mentioned above and group C received normal saline.Thirty minutes later,4 groups inhaled 3％ sevoflurane for 2 hours.Morris water maze test was performed 1 day before anesthesia and 1,3 and 7 days after anesthesia.Morris water maze test was carried out 1 day before anesthesia and 1 and 7 days after anesthesia,8 rats were sacrificed and brains were removed.Hippocampal tissues were obtained for detection of apoptosis in hippocampal neurons,intracellular [Ca2+]i by flow cytometry and the measurement of Bcl-2 and Bax mRNA expression by RT-PCR.Results Compared with group C,the escape latency,apoptotic rate,[Ca2+]i,Bax mRNA expression and Bax/Bcl-2 ratio were significantly decreased,the frequency of crossing the original platform and Bcl-2 mRNA expression increased in groups N,HS and NHS after anesthesia (P＜0.05).Compared with group NHS,the escape latency,apoptotic rate,[Ca2+]i,Bax mRNA expression and Bax/Bcl-2 ratio were significantly increased,the frequency of crossing the original platform and Bcl-2 mRNA expression were decreased in groups N and HS after anesthesia (P ＜ 0.05).Conclusion Nimodipine combined with 7.5％ HS could reduce apoptosis rate of sevoflurane-induced hippocampal neuron by inhibiting calcium overload in aged rats,and it exerts better protective effects than single drug administration.
ABSTRACT
Objective To compare the anterograde amnesia produced by midazolam,propofol and dexmedetomidine when used to supplement sedation during neuraxial anesthesia.Methods Sixty patients of both sexes,aged 18-50 yr,with body mass index of 23-26 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective operation on lower limbs with neuraxial anesthesia,were divided into 3 groups (n =20 each) using a random number table:midazolam group (group M),propofol group (group P) and dexmedetomidine group (group D).When the height of anesthesia was kept below T10,midazolam in a loading dose of O.05 mg/kg was intravenously injected in group M,propofol in a loading dose of O.4 mng/kg was intravenously injected in group P,and dexmedetomidine in a loading dose of 0.6 μg/kg was intravenously injected in group D.The infusion rate of the 3 drugs was adjusted to maintain bispectral index value at 82-86.When Observer's Assessment of Alertness/Sedation Scale scores achieved 3 or 4 after administration,anterograde amnesia was measured by postoperative recall of cards.The development of intraoperative hypotension,bradycardia and respiratory depression was recorded.Results Compared with group M,the incidence of global amnesia was significantly decreased in P and D groups (P＜0.05).There was no significant difference in the incidence of global amnesia between group P and group D (P＞ 0.05).No patients developed hypotension,bradycardia or respiratory depression in three groups.Conclusion Midazolam produces better anterograde amnesia than propofol and dexmedetomidine when used to supplement sedation during neuraxial anesthesia.
ABSTRACT
Objective To evaluate the effect of nimodipine combined with 7.5％ hypertonic saline (HS) on postoperative cognitive function in aged rats.Methods Ninety-six healthy male Wistar rats,aged 18 months,weighing 450-500 g,were assigned into 4 groups (n=24 each) using a random number table:splenectomy group (group S),nimodipine group (group N),group HS and nimodipine plus HS group (group N+HS).Nimodipine 1 mg/kg was intraperitoneally injected in group N.In group HS,7.5％ HS 4 ml/kg was injected via the caudal vein.The equal volume of normal saline was injected intraperitoneally or via the caudal vein in group S.Splenectomy was performed under sevoflurane anesthesia at 30 min after the end of administration.On 1 day before operation and 3 and 7 days after operation,Morris water maze test was performed,and blood sainples from the caudal vein were simultaneously collected for determination of the concentrations of serum S100β protein and neuron-specific enolase (NSE) by enzyme-linked immunosorbent assay.Results Compared with group S,the frequency of crossing the original platform was significantly increased,the escape latency was shortened,and the concentrations of serum S100β protein and NSE were decreased at each time point after operation in N,HS and N+HS groups (P＜0.05).Compared with group N or group HS,the frequency of crossing the original platform was significantly increased,the escape latency was shortened,and the concentrations of serum S100β protein and NSE were decreased at each time point after operation in group N+HS (P＜0.05).Conclusion Nimodipine combined with 7.5％ HS exerts better efficacy than either alone in improving postoperative cognitive function in aged rats.
ABSTRACT
Objective To evaluate the role of calpain in sevoflurane anesthesia-induced apoptosis in hippocampal neurons of aged rats.Methods Fifty-four healthy female Sprague-Dawley rats,aged 18 months,weighing 450-550 g,were randomly divided into 3 groups (n=12 each) using a random number table:control group (group C),sevoflurane group (Sev group) and calpain inhibitor M DL28170 group (group M).In group C,the rats inhaled 50％ O2-50％N2 for 3 h.In Sev group,the rats inhaled 3％ sevoflurane for 3 h.In group M,MDL28170 10 mg/kg was injected via the tail vein,30 min later 3％ sevoflurane was inhaled for 3 h,and MDL28170 was simultaneously infused at 3.33 mg · kg 1 · h-1 via the tail vein.Nine rats in each group were selected,and cognitive function was assessed by using Morris water maze test at 30 min before anesthesia and 1-5 days after anesthesia.The escape latency and frequency of crossing the original platform were recorded.After the end of Morris water maze test performed at 30 min before anesthesia and 1-5 days after anesthesia,3 rats in each group were sacrificed,and hippocampal tissues were obtained for detection of cell apoptosis (by flow cytometry) and intracellular [Ca2+] i.Apoptotic rate was calculated.Results Compared with group C,the escape latency was significantly prolonged,and the frequency of crossing the original platform was decreased,and the apoptotic rate and intracellular [Ca2+]i were increased at 1 day after anesthesia in Sev and M groups.Compared with group Sev,the escape latency was significantly shortened,the frequency of crossing the original platform was increased,and the apoptotic rate was decreased at 1 day after anesthesia,and no significant change was found in intracellular [Ca2+]i in group M.Conclusion Calpain activation is involved in sevoflurane anesthesia-induced apoptosis in hippocampal neurons of aged rats.
ABSTRACT
Objective To evaluate the effects of the prone position on pulmonary gas exchange during mechanical ventilation under general anesthesia.Methods Thirty patients scheduled for elective spine surgery in the prone position under general anesthesia (group prone,n =30),30 patients scheduled for elective spine surgery in the supine position under general anesthesia (group supine,n=30),aged 30-64 yr,with body mass index of 19-30 kg/m2,of ASA physical status Ⅰ or Ⅱ,were enrolled in the study.After induction of general anesthesia,the patients were mechanically ventilated.Anesthesia was maintained with total intravenous anesthesia.At 10 min before pre-oxygenation (T0),10 min after intubation (immediately after the patients were moved from the supine to the prone position) (T1),45 and 90 min after intubation (T2,3),5 min before extubation (immediately before supine position to the prone position) (T4),and 15 min after extubation (T5),arterial blood samples were taken for blood gas analysis,and PaO2 and PaCO2 were recorded.Alveolar-arterial oxygen difference (A-aDO2) was calculated.Digital radiography was performed and the changes of the lung were observed.Results Compared with supine group,PaO2 was significantly increased and A-aDO2 was decreased at T1-4 in prone group.There was no significant difference in PaCO2,and PaO2 and A-aDO2 at T0 and T5 between the two groups.The results of digital radiography showed no atelectasis at different time points in either group.Conclusion Pulmonary gas exchange in the prone position is superior to that in the supine position during mechanical ventilationunder general anesthesia.
ABSTRACT
Objective To evaluate the effect of preconditioning with nimodipine on postoperative cognitive dys function of aged rats.Methods Ninety healthy male Sprague-Dawley rats,aged 18 months,weighing 400-500 g,were randomly divided into 3 groups (n =30 each) using a random number table:nimodipine control group (group N),surgery group (group S),and nimodipine + surgery group (N+ S group).In N and N + S groups,nimodipine 1 mg/kg was intraperitoneally injected,while the equal volume of normal saline was given instead in S group.30 min later,group N inhaled pure oxygen for 2 h,and S and N + S groups inhaled 1.8 ％ isoflourane for 2 h when splenectomy was performed.Morris water maze test was performed on 1 day before operation and 1st,3rd and 7th days after operation.After the end of Morris water maze test at 1 day before operation and 1st and 7th days after operation,10 rats were sacrificed and brains were removed and hippocampi were isolated for determination of apoptosis in hippocampal neurons,intracellular [Ca2+] i in cytoplasm,and hippocampal Bcl-2 and Bax mRNA expression and for examination of ultrastructure of hippocampal neurons.Results Compared with the value before administration,the escape latency was significantly prolonged,the frequency of crossing the original platform was decreased,apoptotic rate and [Ca2+]i were increased,Bcl-2 mRNA expression was down-regulated,and Bax mRNA expression and Bax/Bcl-2 mRNA ratio were up-regulated at each time point after operation in S and N + S groups,and no significant changes were found in the parameters mentioned above in N group.Compared with group S,the escape latency was significantly shortened,the frequency of crossing the original platform was inecreased,apoptotic rate and [Ca2+]i were decreased,Bcl-2 mRNA expression was up-regulated,and Bax mRNA expression was down-regulated at each time point after operation in group N + S.Pathological changes were found in S and N + S groups and the damage was severer in S group than in N + S group.Conclusion Nimodepine preconditioning can prevent postoperative cognitive dysfunction of aged rats,and inhibition of calcium overloadinduced apoptosis in hippocampal neurons may be involved in the mechanism.
ABSTRACT
Objective To evaluate the effects of sevoflurane preconditioning on postoperative cognitive dysfunction in aged rats.Methods One hundred and twenty healthy male Sprague-Dawley rats,aged 18 months,weighing 400-450 g,were randomly divided into 3 groups (n =40 each) using a random number table:control group (group C),operation group (group O),and sevoflurane preconditioning group (group Sev).In group C,the rats were only anesthetized with pentobarbital sodium and did not undergo operation.In group O,the rats were anesthetized with pentobarbital sodium and underwent 30 min of exploratory laparotomy.In group Sev,the rats inhaled 2.4％ sevoflurane for 30 min and then inhaled air for 30 min,and the other procedures were similar to those previously described in group O.At 30 min before operation and on 1st,3rd,5th and 7th days after operation,Morris water maze test was performed to record the escape latency,time of staying at the original platform quadrant and frequency of crossing the original platform.At 30 min before operation and on 1st and 7th days after operation,10 rats in each group were sacrificed and hippocampi were isolated to detect the apoptotic rate and intracellular [Ca2 +] i (using flow cytometry) and the ultrastructure of hippocampal neurons was observed with transmission electron microscope.Results Compared with group C,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,the frequency of crossing the original platform was decreased,and the apoptotic rate and intracellular [Ca2 +] i were increased after operation in O and Sev groups (P ＜0.05).Compared with group O,the escape latency was significantly shorten,the time of staying at the original platform quadrant was prolonged,the frequency of crossing the original platform was increased,and the apoptotic rate and intracellular [Ca2+]i were decreased after operation in group Sev (P ＜ 0.05).Microscopic examination showed no abnormality in the ultrastructure of hippocampal neurons in group C,and the pathological changes of the ultrastructure of hippocampal neurons were obvious in group O,and were significantly attenuated in group Sev.Conclusion 2.4％ sevoflurane preconditioning can reduce postoperative cognitive dysfunction in aged rats,and regulation of imbalance of calcium homeostasis and reduction of cell apoptosis are involved in the mechanism.
ABSTRACT
Objective To evaluate the effect of isoflurane on the apoptosis of SH-SYSY cells transfected with APPsw gene and the role of inositol 1,4,5-triphosphate (IP3) recepters.Methods The SH-SYSY ceils transfected with APPsw gene were seeded in culture flasks with the density of 1.2 × 104/cm2.The cells were randomly divided into 4 groups (n =6 each):control group (group C),IP3 receptor antagonist group (group Ⅹ),isoflurane group (group Ⅰ) and isoflurane + IP3 receptor antagonist group (group Ⅰ + Ⅹ).After the cells were cultured for 24 h and attached to the wall,the cells were cultured routinely in group C,and Xestospongin C 100 nmol/L (IP3 receptor antagonist) was added to DMEM culture medium in groups X and Ⅰ + X,and 30 min later the cells were exposed to 1.2 ％ sevoflurane for 8 h in groups Ⅰ and Ⅰ + X.The cells were collected for examination of the ultrastructure and for determination of cell apoptosis,intracellular free calcium ion concentration [Ca2 +] i (by flow cytometry) and expression of IP3 receptor protein (by Western blot).The apoptosis rate was calculated.Results Compared with group C,there was no significant change in the apoptosis rate,[Ca2 +]i or IP3 receptor protein expression in group Ⅹ (P ＞ 0.05),while the cell apoptosis rate and [Ca2 +] i were significantly increased and IP3 receptor protein expression was up-regulated in groups I and Ⅰ + Ⅹ (P ＜ 0.05 or 0.01).Compared with group Ⅰ,cell apoptosis rate and [Ca2+]i were significantly decreased and IP3 receptor protein expression was down-regulated in group Ⅰ + Ⅹ (P ＜ 0.01).The pathological changes of the cells happened in groups Ⅰ and Ⅰ + Ⅹ,and the pathological changes were severer in group Ⅰ than in group Ⅰ + Ⅹ.Conclusion Isoflurane can induce apoptosis of SH-SY5Y cells transfected with APPsw gene through increasing [Ca2+]i and up-regulating IP3 receptor protein expression.
ABSTRACT
Objective To investigate the effects of isoflurane on the cell cycle and apoptosis in PC12 cells.Methods The neuronal PC12 cells were cultured for 7 d with nerve growth factor in vitro.The cells were cultured in 25 cm2 culture flask and randomly divided into 2 groups (n=6 each): control group (group C) and isoflurane group (group Ⅰ).The neuronal PC12 cells were exposed to 1.2％ isoflurane for 12 h in group Ⅰ.The cell morphology was examined by light microscopy.The apoptotic rate,cell cycle progression,mitochondrial membrane potential (MMP) and intracellular Ca2 + concentrations ([Ca2 +]i) were assessed by flow cytometry.Results Compared with group C,the cell morphology was changed,the proportion of the cells in Go/G1 phase and MMP were significantly decreased,and the proportion of the cells in G2/M phase,apoptotic rate and [Ca2+]i were significantly increased in group Ⅰ (P ＜ 0.05).Conclusion Exposure of PC12 cells to 1.2％ isoflurane for 12 h can activate the cell cycle abnormally and result in cell apoptosis.
ABSTRACT
ObjectiveTo investigate the effect of isoflurane preconditioning on glutamate-induced apoptosis in rat neuronal PC12 cells.MethodsThe PC12 cells were cultured for 5 d with nerve growth factor in vitro.The cells were seeded into 6-cm-diameter culture dishes (3 ml/dish) or 6-well plates (2 ml/well) with the density of 5 × 104/ml and randomly divided into 4 groups (n =18 each): normal control group (group C); glutamate group (group G) ;glutamate + isoflurane group (group GI) and glutamate + isoflurane + xestospongin C (an antngon of inositol trisphosphate receptors) group (group GIX).The neuronal PC12 cells were exposed to glutamate 500 μmol/L in groups G,GI and GIX.The neuronal PC12 cells were exposed to 1.2％ isoflurane for 2 h in groups GI and GIX.Xestospongin C was added to the culture medium immediately before isoflurane preconditioning.Glutamate was added to the culture medium at 10 min after isoflurane preconditioning in groups GI and GIX.The cells were collected from six dishes or wells in each group after being incubated with glutamate for 20 min.The apoptosis and mitochondiral membrane potential (MMP) were assessed by flow cytometry.Intracellular Ca2+ concentration ([ Ca2+ ] i)was detected by confocal fluorescence microscopy.ResultsCompared with group C,the apoptotic rate and [Ca2+ ]i were significantly increased and MMP was decreased in groups G and GIX ( P ＜ 0.01 ),but there was no significant difference in the variables mentioned above in group GI (P ＞ 0.05).Compared with group G,the apoptotic rate and [ Ca2 + ]i were significantly decreased and MMP was increased in groups GI and GIX ( P ＜ 0.05 or 0.01).Compared with group GI,the apoptotic rate and [Ca2+ ]i were significantly increased and MMP was decreased in group GIX ( P ＜ 0.01 ).ConclusionIsollurane preconditioning can inhibit apoptosis in rat neuronal PC12 cells by activating inositol trisphosphate receptors,inhibiting Ca2+ release from the endoplasmic reticulum and increasing MMP.
ABSTRACT
Objective To evaluate the role of M3 muscarinic acetylcholine receptor (M3 mAChR) in the release of glycinergic neurotransmitter by using oxotremorine-M (Oxo-M: a nonselective mAChR agonist) and 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP: a highly selective M3mAChR antagonist). Methods Twenty male 3-4 weeks old SD rats weighing 160-180 g after successful intrathecal catheterization were randomized into 2 groups (n = 10 each): normal saline group (group NS) and pertussis toxin (group PTX).Pertussis toxin 1.5 μg/10 μl was injected IT in group PTX, while in group NS normal saline 10 μl was injected IT instead. The animals were killed at day 7 after injection. The spinal cords were removed and sliced and placed in artificial CSF. Glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) were measured in spinal lamina Ⅱneurons using whole-cell voltage-clamp technique. Five minutes after sealing, Oxo-M (final concentration 3 μ mol/L) was added. Oxo-M was then completely washed out 3 min later and 4-DAMP (final concentration 25 nmol/L) was added after 5 min of stabilization. In the presence of 4-DAMP, Oxo-M (final concentration 3 μmol/L) was added again 3 min later. sIPSCs were recorded before addition of Oxo-M (T1), 3 min after addition of Oxo-M (T2), 3 min after addition of 4-DAMP (T3), 3 min after the second addition of Oxo-M (T4). Results Compared with the baseline value at T1 , Oxo-M significantly increased the frequency of glycinergic sIPSCs at T2without changing the amplitude at T2-4 in both groups. The frequency of sIPSCs was significantly lower at T4 than at T2 in both groups (P ＜ 0.05 or 0.01). There was no significant difference in both frequency and amplitude of glycinergic sIPSCs between the two groups. Conclusion M3 mAChR plays a predominant role in the release of glycinergic transmitter in the spinal lamina Ⅱ neurons in rats.