ABSTRACT
Objective To investigate effect of carnosine on oxygen glucose deprivation/reperfusion ( OGD/RP) induced injury in rat brain slices. Methods Injury of brain slices was determined by TTC methods.The contents of ATP, ADP and AMP were determined by high performance liquid chromatography.Reactive Oxygen species ( ROS) were determined by fluorescence methods.Results Compared with control group, rat hippocampal slices were significantly damaged by OGD/RP, indicated by light color and decreased A490 nm value of TTC staining.Meanwhile the contents of ATP and ADP were significantly decreased, and the content of AMP and ROS were significantly increased, the difference between two group was significant ( P<0.01).Pre-incubation with Carnosine (1000, 200, 40 μg/mL) significantly inhibited the light color and decreased A490 nm value of TTC staining, increased the contents of ATP, ADP and AMP, and decreased the content of ROS, the difference between two group was significant ( P <0.01 ) . Conclusion Carnosine can protect rat hippocampal slices against injury induced by OGD/RP, which may relate to improve the energy metabolism and strengthen the ability of anti-oxidative stress.
ABSTRACT
Objective To investigate the protective effects and mechanisms of propofol and Xingnaojing injection on different characteristic injuries in cerebrocortical slices of newborn rats in vitro. Methods The cerebral cortex of the 7 days-old Sprague-Dawley(SD)neonatal rat was cut into slices. 2,3,5-Triphenyl Tetrazolium(TTC) was used to stain the slices to judge their activities,afterwards they were randomly divided into seven different groups (each,n=12):normal control group(group A),glutamate(Glu)injury group(group B),hydrogen dioxide(H2O2) injury group(group C),propofol preconditioning before Glu injury group(group D),Xingnaojing preconditioning before Glu injury group(group E),propofol preconditioning before H2O2 injury group(group F), Xingnaojing preconditioning before H2O2 injury group(group G). On the 3rd day,the pre-medical treatments or pre-conditionings for D,E,F and G groups were carried out for 24 hours(the concentration of propofol:20 mg/L,the concentration of Xingnaojing:10 μg/mL);the slices were successfully incubated for 4 days,afterwards they were immersed in 1 mmol/L Glu and 0.1 mmol/L H2O2 for 30 minutes respectively to establish the injury models which had no pre-treatment,finally all the groups were transferred into normal cultural medium to incubate till the 7th day. In the above processes,the group A had no specific medical treatment. After all the operations,the changes in brain tissue and cell morphology,the quantity of Nissl body(NISSL)stained by its stain,and the proportion of cells stained with red and green dye after the slices in various groups stained with propidium iodide-acridine orange(PI-AO)were observed,and the apoptosis rate was tested by flow cytometry. Results ①Morphological observation of brain slices:on the 3rd day,the slices appeared mild edematous,3-5 days later,the edema gradually disappeared. Until the 6th day, a large number of typical nerve cells and a few glial cells were seen;on the 7th day,the growth of cells reached the peak,and afterwards,gradually apoptosis played the leading role.②Morphological observation of brain slices stained by hematoxylin-eosin(HE)stain:the neurons of group A presented multilateral-or shuttle-shaped. The cell numbers of groups B and C were significantly lower than the number of group A. In the neuron number sequence,the positions of the numbers of groups D,E,F,G were located in the interval between the number of group A and those of groups B and C,and there were differences in number among groups.③NISSL:Nissl-body of group A could be clearly seen. The numbers of Nissl-body in groups B and C were significantly reduced compared with the number in group A(cell/HP:8.8±2.5,10.3±2.5 vs. 28.9±5.1,both P<0.05). The numbers of Nissl-body in groups D and E were obviously increased compared with the number in group B,and the greater increase being in group D(21.5±4.7 vs. 13.4±3.1, P<0.05). The numbers of Nissl-body in groups F and G were markedly increased compared with the number in group C ,and the greater increase being in group F(23.9±1.9 vs. 19.2±4.1,P<0.05). ④ Double staining with PI-AO:in group A,nearly the total number of nuclei presented fluorescent green in color. In groups B and C,a large number of neurons appeared two types of fluorescence and their edges blurred. The proportions of red staining of neuron cytoplasm in groups D and E were lower than the proportion in group B,and the greater decrease being in group D. The proportions of red staining of neuron cytoplasm in groups F and G were lower than the proportion in group C ,and the greater decrease being in group F.⑤Apoptosis rate:the apoptosis rates of groups B and C were higher than the rate of group A〔(22.00±0.64)%,(21.28±1.44)%vs.(8.57±0.67)%,P<0.05〕;the apoptosis rates of groups D and E were lower than group B,the decrease in group D being greater〔(11.94±0.57)%vs.(18.17±0.65)%,P<0.05〕;the apoptosis rates of groups F and G were much lower than the rate of group C,the decrease in group F being greater〔(10.54±1.24)% vs.(13.12±0.13)%,P<0.05〕. Conclusion The pre-treatment of propoful or Xingnaojing injection has protective effect on Glu or H2O2 injury of in vitro rat cerebrocortical slices,and upon the same injury,the brain protective effect of propoful is more powerful than that of Xingnaojing injection.
ABSTRACT
Aim To investigate the protective effects of high concentration fentanyl on the brain slice injury induced by oxygen glucose deprivation(OGD).Methods Rat brain slices were made and randomly assigned to four groups:control(n=10),OGD(n=10),fentanyl 50 ?g?L~(-1)(F_(50),n=10) and fentanyl 500 ?g?L~(-1)(F_(500),n=10).Changes of the neuron injury and apoptosis were observed with TTC staining,LDH releases,TUNEL staining,immunohistochemistry and electromicroscope.In addition,changes of intracellular calcium were measured with confocal laser-scanning microscopy.Results F_(50) and F_(500) attenuated the decrease of TTC staining and the increase of LDH release induced by OGD in brain slices.Neuronal apoptosis and changes of neuronal ultrastructures were attenuated by F_(50) and F_(500).Bcl-2 and Bax protein expressions were increased after OGD.Bax protein expression was decreased by F_(50) and F_(500),while Bcl-2 protein expression was increased by F_(50)and F_(500).Intracellular calcium concentration was increased by OGD and then it was lowered by F_(50) and F_(500).The protective effects of F_(50) were more obvious than that of F_(500).Conclusions High concentrations of fentanyl have neuron protective effects against OGD injury in rat brain slices,and fentanyl 50 ?g?L~(-1) has more obvious protective effects than fentanyl 500 ?g?L~(-1).