ABSTRACT
Objective To evaluate the role of cyclic adenosine monophosphate-protein kinase A-cAMP response element-binding protein (cAMP-PKA-CREB) signaling pathway in hypoxic preconditioninginduced reduction of propofol-induced central neurotoxicity in the developing rats.Methods A total of 70 SPF male Sprague-Dawley rats,aged 7 days,weighing 10-15 g,were divided into 7 groups (n=10 each) using a random number table method:normal saline group (N group),propofol group (P group),hypoxic preconditioning plus propofol group (HP group),hypoxic preconditioning plus propofol plus PKA inhibitor H89 group (HPH group),propofol plus PKA agonist SP-CAMP group (PS group),normal saline injected via the lateral cerebral ventricle group (NI group),and 5％ dimethyl sulfoxide (DMSO) injected via the lateral cerebral ventricle group (DI group).In P group,propofol 50 mg/kg was intraperitoneally injected,and an increment of propofol 50 mg/kg was given after recovery of righting reflex.The equal volume of normal saline was given instead in N group.In HP group,hypoxic preconditioning (rats were subjected to 5 cycles of 10-min hypoxia of 8％ O2 and 1O-min normoxia of 21％ O2) was performed,and propofol was intraperitoneally injected at 2 h after the end of hypoxic preconditioning and the method was similar to those previously described in P group.In HPH group,H89 5 μmol/5 μl was injected via the lateral cerebral ventricle,and 30 min later the other treatment was similar to those previously described in HP group.In PS group,SP-CAMP 20 nmol/5 μl was injected via the lateral cerebral ventricle,and 30 min later propofol was injected using the method previously described in P group.In NI and DI groups,5 μl normal saline and 5％ DMSO were injected via the lateral cerebral ventricle,respectively.Rats were immediately sacrificed after the righting reflex was recovered,brains were removed and hippocampi were isolated and cut into sections which were stained with haematoxylin and eosin for determination of PKAc and p-CREB positive cells (by i mmuno-histochemistry) and expression of cleaved caspase-3,Bcl-2,Bax,PKAc and posphorylated (p-CREB) protein (by Western blot).Results Compared with N group,the expression of cleaved caspase-3 and Bax was significantly up-regulated,the expression of Bcl-2,PKAc and p-CREB was downregulated,and the percentage of PKAc and p-CREB positive cells was decreased (P＜0.05),hippocampal cells had irregular arrangement,and cells was atrophied in P group.Compared with P group,the expression of cleaved caspase-3 was significantly down-regulated,the expression of Bcl-2,PKAc and p-CREB was up-regulated,and the percentage of PKAc and p-CREB positive cells was increased in HP and PS groups,and the expression of Bax was down-regulated (P＜0.05),the hippocampal cells were arranged neatly,the cytoplasm was abundant,and the nuclei were visible in HP group.Compared with HP group,the expression of cleaved caspase-3 was significantly up-regulated,the expression of Bcl-2,PKAc and p-CREB protein was down-regulated and the percentage of PKAc and p-CREB positive cells was decreased (P＜0.05),the cells had irregular arrangement and shrinked,and nuclear condensation was found in cells in HPH group.Conclusion The mechanism by which hypoxic preconditioning reduces propofol-induced central neurotoxicity may be related to activating cAMP-PKA-CREB signaling pathway in the developing rats.
ABSTRACT
Objective To evaluate the effect of dexmedetomidine on the expression of nerve growth factor (NGF) in isolated hippocampal neurons of fetal rats incubated with propofol.Methods Hippocampal neurons derived from the fetal rats of pregnant Sprague-Dawley rats at 5-13 days of gestation were primarily cultured for 7 days,and were inoculated in the culture plate at a density of 5×105 cells/ml.The neurons were randomly divided into 3 groups (n =15 each) using a random number table:control group (group C),propofol group (group P),and dexmedetomidine + propofol group (group DP).In group P,propofol with the final concentration of 100 μmol/L was added to the culture medium,and the cells were incubated for 3 h.In group DP,dexmedetomidine with the final concentration of 1 μmol/L was added to the culture medium,the cells were incubated for 30 min,and then propofol with the final concentration of 100 μmol/L was added to the culture medium,and the cells were incubated for 3 h.The viability of hippocampal neurons was assessed by CCK-8 assay.NGF mRNA expression was detected by real-time reverse transcriptase polymerase chain reaction.NGF protein expression was detected by Western blot.Results Compared with group C,the viability of hippocampal neurons was significantly decreased,and the expression of NGF protein and mRNA was down-regulated in group P (P＜0.05).Compared with group P,the viability of hippocampal neurons was significantly increased,and the expression of NGF protein and mRNA was up-regulated in group DP (P＜0.05).Conclusion Dexmedetomidine improve propofol-induced decrease in the viability of isolated hippocampal neurons of fetal rats through up-regulating the expression of NGF.
ABSTRACT
OBJECTIVE:To analyze the dyeing status of cinnabar and its pieces,and provide reference for its quality clinical safetey appicaton. METHODS:TLC was used for the qualitative identification of amaranth,carmine,erythrosine,acid red 73, 808 udan and indirubin. HPLC-MS was used to detect the 808 udan :HPLC conditions were as follows,column was Acquity UPLC BEH C18 with mobile phase of cetonitrile-0.1% formic acid(70∶30,V/V)at a flow rate of 0.3 ml/min,the detection wave-length was 520 nm;MS conditions were as follows,ion source was electrospray ionization source,scanning mode was positive ion scanning with full scanning tandem mass spectrometry,nebulizer pressure was 30 psi,drying gas was nitrogen,ion spray voltage was 4 000 V,collision energy was 30 V,and the injection volume was 5 μl. The volumetric method was used for content determi-nation of HgS. RESULTS:TLC spots of amaranth,carmine,erythrosine,acid red 73,808 udan and indirubin were clear and well-separated. 4 batches of 808 udan dyeing were included in the 18 batches of samples,6 batches had non-compliance contents (including 3 batches of 808 udan dyeing). CONCLUSIONS:Dyeing-doped and other quality problems exist in the cinnabaris in markets,which should be noticed.
ABSTRACT
Objective To evaluate the effects of dexmedetomidine on the expression of phosphor-cAMP response element binding protein (p-CREB) in isoloated hippocampal neurons of fetal rats.Methods SpragueDawley rats on 16-18 days of gestation were sacrificed and the fetal rats were obtained.The hippocampi of fetal rats were isolated and hippocampal neurons were seeded in culture medium for 8 days.The cells were then divided into 4 groups (n =12 each) using a random number table:control group (group C),dexmedetomidine 0.001 μmol/L group (group D1),dexmedetomidine 0.010 μmol/L group (group D2),and dexmedetomidine 0.100μmol/L group (group D3).In D1.3 groups,dexmedetomidine with the final concentrations of 0.001 μmol/L,0.010 μmol/L,and 0.100 μmol/L was added to the culture medium,respectively,and then the cells were incubated for 3.5 h.The apoptosis in hippocampal neurons was detected by flow cytometry.The expression of p-CREB in hippocampal neurons was determined by RT-PCR and Western blot.Results Compared with group C,apoptosis rate was significantly decreased and the expression of p-CREB was up-regulated in D1.3 groups.Conclusion Dexmedetomidine inhibits apoptosis in isolated hippocampal neurons of fetal rats by up-regulating the expression of p-CREB.
ABSTRACT
Objective To evaluate the effects of propofol on apoptosis in the hippocampal neurons of fetal rats in vitro.Methods The isolated hippocampal neurons were seeded into 96-well plates or 24-well plates at a density of 5 × 104 cells/ml.The cells were randomly divided into 5 groups (n =18 each) using a random number table:control group (group C),in tralipid group (group Ⅰ) and propofol 1,10,100 μmol/L groups (P1-3 groups).In group Ⅰ,10％ intralipid was added to the culture media until the final concentration reached 100 μmol/L.In groups P1-3,propofol was added to the culture media until the final concentration reached 1,10 and 100 μmol/L,respectively,and the cells were then incubated for 3 h.The cell apoptosis was assessed by flow cytometry.The expression of Bcl-2 mRNA and caspase-3 mRNA was detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).The expression of Bcl-2 and actived-caspase-3 protein was determined by Western blot analysis.The apoptosis rate was calculated.Results Compared with group C,the apoptosis rate was significantly increased,the expression of Bcl-2 mRNA and protein was down-regulated,and the expression of caspase-3 mRNA and actived-caspase-3 protein was up-regulated in P1-3 groups (P ＜ 0.05).There was no significant difference in the parameters mentioned above between group Ⅰ and group C (P ＞ 0.05).Conclusion Propofol induces apoptosis in isolated hippocampal neurons by inhibiting Bcl-2 expression and enhancing caspase-3 activity in fetal rats.
ABSTRACT
Objective To evaluate the effects of propofol on the proliferation of hippocampal neurons in fetal rats in vitro.Methods Pregnant Sprague-Dawley rats at 16-18 days of gestation,were sacrificed and the fetal rats were taken out from the abdominal cavity.The hippocampal neurons of the fetal rats were isolated and seeded in culture plates.After being cultured for 9 days,the neurons were divided into 7 groups using a random number table(n =36 each):control group (C group),intralipid group (I group) and propofol 0.1,1.0,10.0,100.0,1 000.0 μmol/L groups (P1-5 groups).In group I,10％ intralipid was added to the culture media until the final concentration reached 100 μmol/L.In P1-5 groups,propofol was added to the culture media until the final concentration reached 0.1,1.0,10.0,100.0 and 1 000.0 μmol/L,respectively.The neurons were then incubated for 3 h.The proliferation of hippocampal neurons was determined by MTT assay at 12,24,36,48,60 and 72 h after the end of incubation with propofol.Results Compared with group C,the proliferation of hippocampal neurons was significantly decreased in P1-5 groups (P ＜ 0.05),while no significant change was found in group I (P ＞ 0.05).Compared with group P1,the proliferation of hippocampal neurons was significantly decreased in group P5 (P ＜ 0.05),while no significant change was found in P2-4 groups (P ＞ 0.05).Conclusion Propofol can decrease the proliferation of hippocampal neurons in fetal rats in vitro.
ABSTRACT
Objective To evaluate the effects of propofol on the intracellular calcium ion concentration ([Ca2+ ]i) and nuclear factor kappa B (NF-κB) activity in hippocampal neurons of fetal rats in vitro .Methods Ten pregnant Sprague-Dawley rats at 16-18 days of gestation ,were sacrificed and the fetal rats were taken out from the abdominal cavity .The hippocampal neurons of the fetal rats were isolated and seeded in culture plates .After being cultured for 9 days ,the neurons were divided into 7 groups ( n=12 each ) using a random number table :control group (C group) ,intralipid group (I group) and propofol 0.1 ,1 ,10 ,100 ,1 000 μmol/L groups (P1-5 groups) .In group I ,10% intralipid was added to the culture media until the final concentration reached 100μmol/L .In P1-5 groups ,propofol was added to the culture media until the final concentration reached 0.1 ,1 ,10 , 100 and 1 000μmol/L ,respectively .The cells were then incubated for 3 h .The [Ca2+ ]i and cellular morphology of hippocampal neurons were examined by laser scanning confocal microscopy before incubation with propofol and within 10 min after the end of incubation with propofol .The expression of NF-κB protein in the nucleus was detected at 7 days after the end of incubation with propofol by Western blot analysis to reflect NF-κB activity . Results Propofol increased [Ca2+ ]i in P2-4 groups ,while decreased [Ca2+ ]i in group P5 ( P0.05 ) .The structure of hippocampal neurons was normal in C ,I and P1 groups .The branchings of axons and dendrites in hippocampal neurons were significantly decreased in P 2-4 groups , while the structure of hippocampal neurons became fuzzy , the cell membrane was destroyed and the axons and dendrites were not seen in group P5 .Conclusion Propofol can produce neurotoxic effects on hippocampal neurons of fetal rats by changing the [Ca2+ ]i and promoting NF-κB activation in vitro .