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@#This study aimed at investigating the correlations between antidepressive effect of valproate and improvements of NET and 5-HTT expression in depressive rats leaded by chronic mild unpredicted stress(CUMS)with solitary condition. Sixty male SD rats were divided into normal group(NG), model group(MG), valproate treated-normal group(VNG), and valproate treated-model group(VMG), randomly. The changes of depressive behaviors were evaluated by the open-field test and force swimming test. The contents of MDA, activities of SOD and CAT in serum, the mRNA and protein expression of NET, 5-HTT in hippocampus were determined by biochemical methods, Real-time PCR and Western Blot, respectively. Results showed that CUMS can significantly decrease the activities in open-field test, SOD and CAT activities in serum, expression of 5-HTT in hippocampus, and obviously increase the immobility time in force swimming test, the level of MDA and expression of NET. The treatment of valproate obviously improved the changes induced by CUMS. However, the treatment of valproate had no significant influences on behaviors of NG rats. So, it revealed that improvements of the mRNA and protein expression of NET, 5-HTT may be involved in the antidepressive effect of valproate.
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Aim To investigate whether chronically un-predictable stress (CUS)-induced depression-like be-haviors of rats is associated with the variant expression of tryptophan hydroxylase (TPH)and tyrosine hydrox-ylase (TH).Methods 30 male SD rats were ran-domly divided into depression model group(MG)and control group (CG),the former was established using CUS plus solitary condition for 28 d,whereas the latter was fed normally as five rats per cage without CUS. The open field test(OFT)and the sucrose preference test were used to evaluate depressive behaviors.Both mRNA and protein expressions of TPH and TH in hip-pocampus and forebrain cortex were determined by re-al-time fluorescent quantitative PCR and western blot (WB),respectively.Results MG rats showed obvi-ous depressive behaviors with much lower locomotive activity and sucrose preference than CG.Meanwhile, the mRNA and protein expressions of TPH and TH also significantly decreased in MG rats,compared with CG rats.Conclusion The depression behaviors of rats in-duced by CUS may be associated with down-regulation of TPH and TH expression.
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Objective To optimize the antibacterial drug regimen in ICU common staphylococcal infection.Methods The pharmacokinetic and pharmacodynamic parameters of antibacterial drugs were collected in combination with the hospital ICU anti-microbial drug resistance monitoring reports from the national antimicrobial resistance investigation net (Mohnarin)of the Ministry of Health and the performance standards for antimicrobial susceptibility testing (2013)issued by the clinical and laboratory stand-ards institute (CLSI),the minimum inhibitory concentration (MIC)of staphylococci was set by using the discrete uniform distribu-tion method and 16 kinds of administration regimens with 6 antimicrobial agents were worked out.The best initially antimicrobial regimen was optimized by using the pharmacokinetic and pharmacodynamic models and Monte Carlo simulations of cumulative frac-tion of response (CFR)from 5 000 patients.Results The alternative initially drug regimens to the infectious bacteria were:linezolid 0.40 g twice daily and vancomycin 0.75 g twice daily for staphylococcus aureus;amikacin 0.60 g once daily and linezolid 0.40 g twice daily,and vancomycin 0.75 g twice daily for hemolytic staphylococci and staphylococcus epidermidis;linezolid 0.40 g twice daily and vancomycin 0.75 g twice daily for methicillin-resistant Staphylococcus aureus;ampicillin/sulbactam 1.50 g 4 times daily, cefuroxime 0.75 g 4 times daily,amikacin 0.60 g once daily,moxifloxacin 0.40 g once daily for methicillin-sensitive staphylococcus aureus.Conclusion In the Staphylococcus aureus infection occurred in ICU,if which being methicillin-sensitive could be deter-mined,ampicillin/sulbactam,cefuroxime,amikacin and moxifloxacin could be selected for treatment,and linezolid or vancomycin could be selected for treating possible methicillin-resistant Staphylococcus aureus infection or undetermined whether being methicil-lin-resistant Staphylococcus aureus infection.
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Aim To investigate the role of COX-2 in BMP9 induced osteogenic differentiation,and the pos-sible mechanism underlying this function of COX-2. Methods We introduced real-time PCR, Western blot, and immunocytochemical staing to detect the effect of BMP9 on COX-2 expression.We employed chemiluminescence technique to assay ALP activities, RT-PCR to detect the expression of Smad6 and Smad7 , and Western blot to measure the expression of Runx2, Dlx-5,total Smad1/5/8,and phosphorylated Smad1/5/8.Finally,BMPR-Smad luciferase reporter assay was applied to measure the activation of BMPs/Smads signaling.Results BMP9 could induce the expression of COX-2 in C3H10T1/2 cells.Either inhibiting enzy-matic activity of COX-2 or knockdown of the expression of COX-2 reduced the BMP9 induced ALP activities in C3H10T1/2 cells,and COX-2 knockdown also inhibited the ectopic bone formation induced by BMP9 in C3H10T1/2 cells.Moreover,COX-2 knockdown inhibi-ted BMPR-Smad reporter activities and the phosphoryl-ation of Smad1/5/8,so did the expression of Smad6 and Smad7 .Conclusion COX-2 may play an impor-tant role in BMP9 induced osteogenic differentiation in MSCs by regulating the BMPs/Smads signaling trans-duction.
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Aim To investigate if anti-depressive effect of venlafaxine was associated with improving oxi-dative stress and expression of hippocampus NET and 5-HTT in rat model induced by CUS. MethodsEighty SD male rats were randomly divided into four groups:model group(MG),normal group(NG), ven-lafaxine-treated normal group ( VNG ) , and venlafax-ine-treated model group ( VMG) . VNG and VMG were given venlafaxine (23. 4 mg·kg-1 ·d-1 ) once daily;NG and MG were given the same volume solvent. Soli-tary condition with chronic unpredicted stress ( CUS ) was taken to establish rat depression model. The force swimming test was used to evaluate the behavior chan-ges of experimental rats. The malondialdehyde ( MDA) level and activity of superoxide dismutase ( SOD ) in serum were determined by biochemical methods. The mRNA and protein expressions of NET and 5-HTT in hippocampus were determined by Real-Time Reverse transcription polymerase chain reaction ( real-time RT-PCR) and Western blot ( WB) , respectively. Results Compared with NG rats, obviously increasing immo-bile time of rats in force swimming test and serum MDA level, as well as significantly decreasing SOD activity in serum was observed with clearly decreasing 5-HTT expression and elevating NET expression in hippocam-pus of MG rats. The treatment of venlafaxine distinctly suppressed changes above from CUS-induced rats. However, significant changes failed to be found in VNG rats. Conclusion The anti-depressive effect of venlafaxine may at least partly involve in improving ox-idative stress/anti-oxidative stress balance and revers-ing abnormal expression of NET and 5-HTT.
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<p><b>OBJECTIVE</b>To investigate the modulating effect on lipid and gene expressions of CPT I A caused by berberine (Ber) in experimental hyperlipidemia rats.</p><p><b>METHOD</b>Male SD rats were randomly divided into 5 groups according to the blood lipid values: normal group, hyperlipidemia group, 300 mg x kg(-1) x d(-1) Ber-treated group, 60 mg x kg(-1) x d(-1) Ber-treated group, and 7.2 mg x kg(-1) x d(-1) lovastatin-treated group. Normal group were fed with base diet and other groups were fed with high fat and cholesterol diet. 12 weeks after drugs were given the TC, TG, LDL-C, and HDL-C from rat blood samples were tested by automatic biochemistry analyzer. Gene expressions of CPT I A and PPARalpha were evaluated by RT-PCR and Western blot, respectively.</p><p><b>RESULT</b>It was shown that Ber significantly decreased TC and LDL-C, but increased HDL-C in dose-dependent manner, elevated expressions of CPT I A mRNA and protein without influence on PPARalpha expression. Similar effects from lovastatin on lipidemia were observed except the Ber effect on CPT I A gene expression.</p><p><b>CONCLUSION</b>Ber has modulating effect on the lipid metabolism, the mechanism of which may be by promoting the CPT I A gene expression.</p>
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Animals , Humans , Male , Rats , Berberine , Carnitine O-Palmitoyltransferase , Genetics , Metabolism , Disease Models, Animal , Drugs, Chinese Herbal , Gene Expression , Hyperlipidemias , Drug Therapy , Genetics , Metabolism , Lipid Metabolism , PPAR gamma , Genetics , Metabolism , Random Allocation , Rats, WistarABSTRACT
A high performance liquid chromatographic method with hypersil C_(18) column, 0.020 mol/L potassium dihydrogen phosphate solution(which contains 0.25% triethylamine, pH 5.1)-methanol(20∶ 80, V/V) as mobile phase and fluorescence detection with 280 nm as excitation wavelength and 320 nm as emission wavelength has been developed for the determination of terbutaline sulfate and propranolol hydrochloride in Erythrocyte suspensions. Erythrocyte surface receptor oscillating reacted 1 h with terbutaline in 37 ℃ water bath. Free terbutaline and propranolol were separated from the membrane receptor-binding complex through 1500 r/min centrifugal in 5 min. The linear range was 0.010-3.000 mg/L in Alsever's solutions and the correlation coefficients were 0.9999 and 0.9998. The relative standard deviations(RSDs) of terbutaline and propranolol were 0.8% and 1.2%, respectively. The limits of detection(LODs) of both were 1.00 and 3.00 mg/L. This simple, safety and sensitive method was suitable for the determination of terbutaline and propranolol in erythrocyte suspensions and for the study of receptor-ligand binding.
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<p><b>OBJECTIVE</b>To investigate the anti-colon cancer effects of berberine and possible relationship with cyclooxygenase-2.</p><p><b>METHOD</b>Wistar rat colon cancer model was induced by 1-2 dimethylhydrazine (DMH) (40 mg x kg(-1), sc) + 1% dextran sodium sulfate solution (DSS) (freely drinking). All rats were randomly divided into 3 groups: Control (DMH + DSS + solvant), meloxicam (Mel) (DMH + DSS + Mel 1.35 mg x kg(-1)), berberine (Ber) (DMH + DSS + Ber 100 mg x kg(-1)). The drugs were given orally once a day for 5 day per week. The body weight, the number of colon ACFs, the incidence and number of colon cancer in rats, as well as the morphological changes of rat colon tissues were evaluated. Human colon cancer lovo cell line was treated by either Ber or Mel in various concentrations (1 10(-6) mol x L(-1), 1 x 10(-5) mol x L(-1), 1 x 10(-4) mol x L(-1), 1 x 10(-3) mol x L(-1)) for 6, 12 and 24 h, respectively, and the cell growth was assayed by MTT method. RT-PCR and western-blot were used to evaluate the mRNA and protein expressions of COX-2 from lovo cells treated with Ber and Mel.</p><p><b>RESULT</b>Ber significantly improved the dyscrasia induced by DMH + DSS, the both of body weight and general condition were better than control group. Ber also significantly inhibited ACF and colon cancer incidence in the rats treated by DMH + DSS for 10 weeks or 20 weeks, which was similar to that of Mel. Ber inhibited the proliferation of lovo cells in concentration- and time-dependent manners, and the IC50 values were significantly smaller than that of Mel at 6, 12 and 24 h after lovo cells were treated by either Ber or Mel. Ber also concentration-dependently decreased expressions of COX-2 mRNA and COX-2 protein from lovo cells.</p><p><b>CONCLUSION</b>Ber can inhibit ACF and tumor formation induced by DMH + DSS, and decrease the lovo cell proliferation index. The anti-tumor effects of Ber may involve in an unknown pathway through which the expressions of COX-2 mRNA and protein were inhibited.</p>
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Animals , Female , Male , Rats , 1,2-Dimethylhydrazine , Toxicity , Aberrant Crypt Foci , Berberine , Therapeutic Uses , Body Weight , Colonic Neoplasms , Cyclooxygenase 2 , Genetics , Dextran Sulfate , Toxicity , RNA, Messenger , Rats, WistarABSTRACT
<p><b>OBJECTIVE</b>To observe the antiulcer effects of pomegranate tannins in animal models.</p><p><b>METHOD</b>Gastric ulcer models were established by pylorus ligation, intragastric absolute ethanol, and water-immersion stress, respectively. The ulcer index, the contents of nitric oxide (NO) and malondialdehyde (MDA), the activities of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) from gastric mucosa of rats, the gastric juice volume, free acidity, total acidity,total acid output, the pepsin activity, the amount of adherent mucus and free mucus were measured, respectively.</p><p><b>RESULT</b>Pomegranate tannins (500, 150, 50 mg x kg(-1)) significantly inhibited ulcerative formation induced by both water immersion stress and pylorus ligation, obviously decreased the gastric mucosa damages induced by intragastric absolute ethanol, in dose-dependent manner. Pomegranate tannins significantly inhibited absolute alcohol-induced elevation of MDA as well as decreasing of NO level, and activities of both SOD and GHS-PX from gastric mucosa. Pomegranate tannins significantly increased the secretion of adherent mucus and free mucus, but did not affect elevation of the free acidity, total acidity, and total acid output, gastric juice volume, gastric pepsin activity induced by pylorus ligation.</p><p><b>CONCLUSION</b>Pomegranate tannins play a protective role against gastric ulcer. Its antiulcer effect is related to increasing secretion of adherent mucus and free mucus from the stomach wall, which may inhibit generation of oxygen-derived free radicals, and decrease the consumption of GSH-PX and SOD, and maintain content of NO at normal level.</p>
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Animals , Female , Male , Mice , Rats , Anti-Ulcer Agents , Therapeutic Uses , Disease Models, Animal , Ethanol , Gastric Juice , Nitric Oxide , Plant Extracts , Therapeutic Uses , Lythraceae , Chemistry , Pylorus , Rats, Sprague-Dawley , Stomach Ulcer , Drug Therapy , Tannins , Therapeutic UsesABSTRACT
Peroxisome proliferator-activated receptoralpha (PPARalpha) is a ligand-activated transcription factor which plays a pivotal role in the regulations of metabolism. A cDNA encoding ligand binding domain (LBD) of PPARalpha was amplified by RT-PCR from human hepatic tissue and the product was inserted into the downstream of the malE gene in the vector pMAL-p2X,which encodes maltose-binding protein (MBP). The recombinant plasmid containing MBP-PPARalpha gene was transformed into E. coli. TB1, and then the growth conditions of the recombinant strain were studied, which remarkably influenced the final yield of protein expression. With the use of SDS-PAGE and Bio-Rad Quantity One gel image analysis, we found the best expression condition as follows: The induction was started as OD600 reached 0.5 by the adding of IPTG to a final concentration of 0.4 mmol/L, and then the incubation continued 6 hours at 30 degrees C. The maximum yield of fusion protein was 31.34% of the total mass of cytoplasm proteins. Moreover, the soluble form of the target protein is useful for further work on purification and on screening the ligands of PPARalpha.
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Humans , Carrier Proteins , Genetics , Electrophoresis, Polyacrylamide Gel , Escherichia coli , Genetics , Metabolism , Genetic Vectors , Genetics , Ligands , Maltose-Binding Proteins , PPAR alpha , Genetics , Recombinant Fusion Proteins , GeneticsABSTRACT
AIM: This study aimed at investigating the effects and mechanism of total alkaloids from Rhizoma Coptidis (TA) on ethanol-induced gastric mucosal injury in rats. METHODS: The experimental gastric damages were established by intragastric ethanol, and the protective effects of TA were evaluated by calculating lesion indices contents and superoxide dismutase (SOD) activity from rat gastric mucosa were measured to explore the interrelation between therapeutic effects of TA and these factors. The expressions of neuronal nitrogen monoxide synthase (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS)from ethanol-damaged gastric mucosa in rats were analysised using immunohistochemical method. RESULTS: TA significantly inhibited the gastric injury induced by ethanol ,in dose-dependent manner,and the effect of TA was superior to that of Berberine (Ber). TA obviously antric mucosa. TA significantly suppressed ethanol-induced decreasing nNOS and eNOS expression and elevation of iNOS expression in rat gastric mucosa. CONCLUSION: Rhizoma Coptidis is a potent candidate in therapeutic drugs of human alcohol-induced gastric injury. Its anti-injury effects involve in Ber and other ingredients of TA. The protective mechanisms of TA involve in inhibiting generation of oxygen-derived free radical, accelerating scavenging of free radicals, relieving lipid peroxidation, and maintaining NO content in normal level by inhibiting decreasing of nNOS and eNOS expression and elevation of iNOS expression.
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OBJECTIVE:To investigate the inhibition effect of berberine on colon carcinoma lovo cell. METHODS:Colon car-cinoma lovo cells were cultured and treated with berberine and meloxicam in various concentrations. At 6 h,12 h and 24 h after treatment,the proliferation of lovo cell was assayed by MTT method. RT-PCR method and Western blot testing were used to eval-uate the mRNA and protein expressions of COX-2 in lovo cell. RESULTS:Berberine with concentration larger than 10-5 mol?L-1 and meloxicam with concentration larger than 10-4 mol?L-1 could inhibit the growth and proliferation of lovo cell and showed concentration and time dependent manners(P
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OBJECTIVE:To study the characteristics of ceftazidime-resistant?-lactamase produced by Escherichia coli.METHODS:The types of2strains of drug fast?-lactamase produced by Escherichia coli were determined initially by K-B slip diffusion method and ampholine electrophoresis method;The plasmid was extracted by alkaline lysis and the PCR ampli?fication and sequencing were conducted;?-Lactamase was counter-extracted by saturated ammonium sulfate,filtrated by Sephadex G-75gel and purified by DE-52anion exchange chromatography;The molecular weight of which was determined by SDS-PAGE and the enzyme kinetics parameters of?-lactamas were determined by ultraviolet spectrophotometry.RE?SULTS:The2strains produced a super-broad spectrum?-lactamase(CTX-M-1V)with isoionic point at8.7and the molecular weight at29kDa,which can hydrolyze cefotaxim and aztreonam but imipenem and which was sensitive to sulbactam(IC 50 =94nmol/L)and tazobactam(IC 50 =5nmol/L).CONCLUSION:CTX-M-1V is a CTX-M type super-broad spectrum?-lactamase sensitive to suppressants.
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BACKGROUND:Cervical cancer is one of the most frequent malignancies in women worldwide, and its occurrence and development is closely related to cyclooxygenase-2 (COX-2).OBJECTIVE: To examine the expression of COX-2 alternative splicing variants in human cervical carcinoma tissue and understand its possible implications.DESIGN: Non-randomized controlled experiment.SETTING: Key Laboratory of Biochemistry and Molecular Pharmacology,Department of Obstetrics and Gynecology, First Affiliated Hospital,Chongqing Medical University.PARTICIPANTS: Carcinoma tissue and normal tissue were obtained from 13 cervical carcinoma patients admitted during March 2002 to April 2002in the Department of Obstetrics and Gynecology, First Affiliated Hospital,Chongqing Medical University.METHODS: A pair of specific primers were designed for reverse transcription-polymerase chain reaction (RT-PCR) to obtain the mRNA of COX-2 in human cervical carcinoma tissues. The resultant band on electrophoresis was cloned, sequenced and analyzed.MAIN OUTCOME MEASURES: ① Agarose gel electrophoresis result of the PCR product of carcinoma and normal tissues; ② Sequencing result of the electrophoresis band from carcinoma and normal tissues.RESULTS: No COX-2 band (252 bp) was found in electrophoresis for normal tissues, while 2 bands appeared for cervical carcinoma tissues, including a new electrophoresis band of 534bp besides the COX-2 band. Cloning and sequencing revealed that this new band contained not only exons 7and 8 of COX-2 gene but also a reserved intron of 282 bp intron between exons 7 and 8. Analysis of the predicted amino acid sequence indicated that an in-frame stop codon occurred in the 48-50 bp of the intron retained in the mRNA.CONCLUSION: The presence of COX-2 alternative splicing mRNA variant (Genbank accession number:BU493602)is confirmed in human cervical carcinoma tissue, which codes for a protein possibly smaller than COX-2.
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Aim To obtain high pure hPPAR?1LBD fusion protein.Methods A cDNA encoding ligand binding domain(LBD)of PPAR?1 was amplified by RT-PCR from human fatty tissue and the product was inserted into the downstream of the malE gene in the vector pMAL-p2X,which encoded maltose-binding protein(MBP).The recombinant plasmid containing MBP-PPAR?1 gene was transformed into E.coli.TB1 and the expression conditions of the recombinant strain were optimized.Results The DNA strap of MW(909 bp) was presented after re-combinant plasmid was digested by Hind Ⅲ and BamH Ⅰ.The high efficient expression of MBP-PPAR?1 fusion protein in TB1 cells was observed with 38.54% product of the total cytoplasm proteins when 0.4 mmol?L-1 IPTG and 6 h incubation were taken at 30℃.Conclusion The recombinant vector was successfully constructed.It could high efficiently express hPPAR?1LBD fusion protein in TB1 cells and obtain the hPPAR?1LBD fusion protein with high bioactivity.
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Aim To investigate the effects of heme oxygenase-1(HO-1) on brain damage due to cerebral ischemia/reperfusion.Methods 120 male mice were divided into four groups randomly and the cerebral ischemia/reperfusion(I/R) model was established through drawing out and reperfusing 40% of the whole blood volume in combination with clamping the carotid arteries for 20 min after anesthesia with 40 g?L-1chloral hydrate(400 mg?kg-1 ip).The mice were intracerebraventricularly(icv) injected with 3(l of150 ?mol?L-1 hemin,150 ?mol?L-1 ZnPPIX,or artificial cerebrospinal fluid(ACSF),respectively 16 h before the model established.Sham operation group only received anesthesia and operation without I/R and icv injection.The hippocampal HO activity and cerebral cortex xanthine oxidase(XO) activity,the levels of malonaldehyde(MDA) and reactive oxygen species(ROS),hippocampal neuron apoptosis,and hippocampal HO-1 expression were determined by spectrophotometer,TUNEL method,and Western blot,respectively.Results The increased hippocampal HO-1 expression and HO activity,decreased XO activity,MDA and ROS levels,and diminished hippocampal apoptosis were observed in the hemin group,compared with ACSF group(P0.05),but inhibited the activity of HO with the elevation of XO activity,MDA and ROS levels,as well as cellular apoptosis(vs ACSF,P
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Aim To study the role of calcineurin signal transduction pathway in the anti-hypertrophic effect of L-arginine in vivo and in vitro.Methods The hypertrophic effects was assayed by calculating the right ventricular hypertrophy index(RVHI=right ventricle weight/left ventricle and septum weight),and atrial natriuretic peptide(ANP)mRNA expression in rat right ventricle hypertrophy model induced by monocrotaline(MCT) or by measuring the cell diameter,protein content,and ANP mRNA expression in hypertrophic cardiomyocyte induced by prostaglandin F2?(PGF2?).For mechanism studies,the intracellular free calcium concentration([Ca2+]i) in cultured cardiomyocytes was measured by using Fura 2/AM as a fluorescent indicator.ANP and CaN mRNA expressions,and expressions of CaN and its downstream effectors,NFAT3 and GATA4 proteins were assayed by RT-PCR and Western blot,respectively,in vivo and in vitro.Results In MCT-hypertrophic model,prevention-and treatment-administration of L-arginine,a nitric oxide(NO) precursor,200 mg?kg-1?d-1,could obviously inhibit the elevated RVHI and ANP mRNA expression;similar to that found in vivo.Addition of L-arginine 1 mmol?L-1 could markedly inhibit the increased cell diameter,protein content and the expression of ANP mRNA in the hypertrophic cardiomyocyte induced by PGF2? 100 nmol?L-1,and it could also decrease the elevated [Ca2+]i in vitro;notably,the above dose or concentration of L-arginine could blunt the elevated expressions of calcineurin mRNA and the calcineurin-,NFAT3-,GATA4-proteins induced by MCT or by PGF2?.These effects of L-arginine were blocked by NG-nitro-L-arginine-methyl ester,a NO synthase inhibitor,in vivo and in vitro.Conclusion These results suggest that calcineurin signal transduction pathway may play an important role in the NO-induced inhibition of cardiac hypertrophy.The anti-hypertrophic effects of L-arginine may involve the decrease of [Ca2+]i,and then inhibit the activated calcineurin pathway,through the release of NO.
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Objective To evaluate the effects of cerebral ischemia/reperfusion or/and icariin on expression of cytochrome C oxidase subunitⅡ(COⅡ) mRNA in mice. Methods The mouse model of transient cerebral ischemia/reperfusion was made by bilateral occlusion of common carotid arteries and ischemic hypotension/reperfusion. The mice were divided into several groups at random: normal control group, model group and icariin preventive treatment group (100 mg/kg). The changes in expression levels of COⅡ mRNA in mice cerebral tissue were detected by RT-PCR at different time points. Results The levels of CO Ⅱ mRNA in model group had no significant changes at 1 h and 24 h after cerebral ischemia/reperfusion as compared with that in control group, but decreased remarkably at 3 h (P
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Aim To study the effects of sodium magnesium fructose diphosphate (SMFD) on free calcium concentration and nitric oxide synthase activity of ischemic synaptosome, so as to explore the protective mechanisms of SMFD on cerebral ischemia. Methods The synaptosomes from normal rat brain were prepared by phase partition and cultured with oxygen-glucose deprivation to establish ischemic synaptosome model. The intrasynaptosomal free calcium concentration and nitric oxide synthase activity were detected separtately after the synaptosomes were co-incubated with SMFD (1.3 mmol*L-1) or fructose-1,6-diphosphate (FDP, 4.0 mmol*L-1) for 60 min. Results SMFD decreased the free calcium concentration and reduced the activity of nitric oxide synthase (NOS) of ischemic synaptosomes. Its effects were more powerful than those of FDP. Conclusion SMFD may protect neurons from ischemic injury by preventing intracellular Ca2+ overload and inhibiting the activity of nitric oxide synthase.
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<p><b>OBJECTIVE</b>To study the dose- and time-dependent protective effects and the synergistic effects of nimodipine (NMDP) and fructose-1,6-diphosphate (FDP) against cerebral damage induced by acute carbon monoxide (CO) poisoning in mice.</p><p><b>METHODS</b>Male mice were exposed to CO 170 mL/kg, i.p. After CO intraperitonealy exposure, mortality of mice, change in memory function estimated by passive avoidance test, the pathomorphologic observation of brain tissue slices, as well as changes of activities of monoamine oxidase (MAO)-B and Ca(2+)-Mg(2+)-ATPase in cerebral tissue were studied. In dose-dependent protective effect study, NMDP (10.6, 5.3, 2.7 mg/kg) and FDP (2.6, 1.3, 0.67 g/kg) was injected ip, respectively 15 min after CO exposure. To study the time-effect relationship of drugs, NMDP (5.3 mg/kg) and FDP (1.3 g/kg) were administered ip respectively 15 minutes, 45 minutes and 120 minutes after CO exposure. The combination of NMDP (2.7 mg/kg) and FDP (0.67 g/kg) was administered ip15 minutes, 45 min and 120 minutes after CO exposure to study the synergism of the two drugs.</p><p><b>RESULTS</b>Either NMDP (10.6, 5.3 mg/kg) or FDP (2.6, 1.3 g/kg) administered ip within 15 minutes after CO exposure significantly decreased the impairment of memory function and mortality rate induced by CO, inhibited the decrease of Ca(2+)-Mg(2+)-ATPase activity, blunted the rising of MAO-B activity and prevented the delayed hippocampal neuronal death in poisoning mice. To our surprise, the combined use of NMDP (2.7 mg/kg) and FDP (0.67 g/kg) within 15 minutes after CO exposure had similar effects to that in NMDP (10.6, 5.3 mg/kg) and FDP (2.6, 1.3 g/kg).</p><p><b>CONCLUSIONS</b>These results suggest that the impairment of CO on brain can be attenuated if NMDP or FDP are administered sufficiently and quickly as soon as possible after CO exposure and there exists a synergism of FDP and NMDP against CO poisoning damage.</p>