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BACKGROUND: Previous studies have found that skeletal muscle satellite cell transplantation can induce angiogenesisin myocardial infarction area, reduce infarct size and improve cardiac function. But the overall effect is not satisfactory.OBJECTIVE: To observe the survival of basic fibroblast growth factor (bFGF) gene modified skeletal muscle satellitecells in acute myocardial infarction and to observe the expression of bFGF gene and the effect of cell transplantation onangiogenesis in myocardial infarction area.METHODS: Eighteen New Zealand white rabbits were divided into three groups by random: skeletal muscle satellite cellgroup (control group), bFGF gene enhanced skeletal muscle satellite cell group (experimental group) and blank controlgroup. The left anterior descending branch of the coronary artery of the rabbits was ligated so as to establish an animalmodel of acute myocardial infarction in the former two groups. After labeled by DAPI before transplantation, the skeletalmuscle satellite cells, bFGF gene modified skeletal muscle satellite cells and the equivalent amount of DMEM/F12 wereinjected into the local infarct myocardium correspondingly. Samples were taken 4 weeks after transplantation. Then, thesurvival of skeletal muscle satellite cells and the expression of bFGF gene were observed under light microscope andfluorescence microscope, and the neovascularization in the myocardial infarction area was examined byimmunohistochemical staining.RESULTS AND CONCLUSION: No DAPI-labeled cells were visible in the blank control group, but in the other twogroups, a large amount of DAPI-labeled skeletal muscle satellite cells were seen in the infarction area. Enhanced greenfluorescent protein was highly expressed in the experimental group. Microvessel density in the infarction area washighest in the experimental group followed by the control and blank control groups (P < 0.05). These findings indicatethat bFGF gene modified skeletal muscle satellite cells can survive and promote neovascularization in the acutemyocardial infarction area.
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Objective To establish a sensitive,simple and accurate HPLC-MS/MS method to quantify glycyrrhetic acid(glyc?yrrhetinic acid)in mice blood,and to further study pharmacokinetic profiles of glycyrrhetic acid after oral administration of glycyrrhi?zin and Bu-Zhong-Yi-Qi-Wan(BY). Methods Rats were intragastric administered of glycyrrhizin(glycyrrhizic acid,61.5 mg/kg) and BY extract(3 g/kg,with the same mole of glycyrrhizin moiety),respectively. Plasma samples were collected after administration and extracted with liquid-liquid extraction,then by separated by liquid chromatography on a C8 reversion phase chromatographic col?umn with gradient elution. Concentration of glycyrrhetic acid was detected by the validated HPLC-MS/MS. Non-compartmental pharma?cokinetic profiles were constructed using the software of Das 2.0 software(Shanghai,China),and the pharmacokinetic parameters were compared using unpaired Student′s t-test. Results This bioanalytical method was fully validated and showed good linearity(r>0.99),wide dynamic range(5-1000 ng/ml),and favorable accuracy and precision. Compared with the glycyrrhizin pure form group, BY significantly reduced the Cmax and AUC0-t of glycyrrhetic acid by 56%and 76%,respectively. Whereas no significant differences in Tmax,T1/2 and MRT were observed between the two groups. Conclusion The constituents in the BY prescription have significantly reduced the oral bioavailability of glycyrrhetic acid in rats than those in the glycyrrhizin pure form and the results indicate that some components in the BY have an inhibition effect on the absorption process of glycyrrhizin in the gut.
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Objective To establish and optimize the rat jugular vein catheterization model in our lab, and perform a cross-over study using this model to compare the pharmacokinetic characters of a newly developed midazolam formulation to the existing preparation. Methods Six SD rats (half male and half female) received the right jugular vein catheterization when the rats were sufficiently anesthetized. One week after the operation, all the rats were used to conduct a cross-over double period pharmacokinetic study. Totally1.33 mg/kg midazolam solutions from automatic needle and clinic available injection were adminisered to the jugular vein catheterization rats via im route. The washout period was 5 days. Exact volume of blood samples at designed time points were taken through the catheter. After preparation, the concentrations of midazolam in rat plasma were determined by using established LC-MS/MS method. The corresponding pharmacokinetic parameters were calculated by WinNolin software. Results The rat jugular vein catheterization model was successfully built. Blood was easily sampled and rats were well tolerated, meeting the requirement of repeated blooding. This model solved the bottleneck of cross-over study performed in rats. The pharmacokinetic behavior of newly developed midazolam formulation had no difference with that of clinic injections. The relative bioavailability was around 99%. Conclusion Rat jugular vein catheterization model is proved to be that of a propagating technique to do the cross-over study and to evaluate the pharmacokinetic characters of novel formulations.
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OBJECTIVE To investigate the effect of ketoconazole on the pharmacokinetic (PK) behaviors of midazolam and its metabolite through intranasal and intragastric(ig) routes in rats. METHODS Twenty-four rats were evenly divided into 4 groups. Two groups of rats were administrated singly with midazolam (1 mg?kg-1) through intranasal or ig route. The other two groups were concomitant with CYP3A inhibitor,ketoconazole(30 mg?kg-1),midazolam(1 mg?kg-1)through the same two routes. Blood samples were collected from different time points. Plasma concentration of midazolam and 1′-hydroxymidazolam was determined. Major pharmacokinetic parameters were calculated and statistical tests were performed by using t test. RESULTS Tmax was about 2 and 25 min for rats administered singly with midazolam via intranasal or ig routes,respectively and AUC was 296 and 179 μg?L-1?h, respectively. When concomitant with ketoconazole,AUC increased to 2.1 and 3.3 folds the original value for intranasal and ig routes,respectively. However,the Tmax value of midazolam via intranasally didn′t change after being coadministrated with ketoconazole,but Tmax increased to 1.14 h via ig. CONCLUSION Compared with administration via ig,intranasal route administrated midazolam displays significant advantages of faster absorption and higher exposure,which are vital for the first aid. Concomitant with CYP3A inhibitor and midazolam via intranasal route,the absorption speed is not affected,but with the metabolism blocked,the systemic exposure is greatly elevated. While via ig,both absorption speed and metabolism are inhibited. The dose should be cut down or the dosing interval increased in clinic practice in this concomitant situation.
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OBJECTIVE To synthesize[3H]labelled trantinterol and determine the mass balance in rats and the profile of trantinterol and its metabolites in excreta. METHODS [3H]Trantinterol was synthesised from the intermediate1-(4-amino-3-chloro-5-trifluoromethyl-phenyl)-2-bromo-ethanone through reduction by sodium borotritide and aminolysis by t-butylamine. Following an oral dose of[3H] trantinterol(45.5 MBq·kg-1)to bile duct cannulated(BDC)rats and normal rats. Bile,urine and faeces were collected individually before and after dosing at different times. Liquid scintillation counter(LSC) was used to detect total radioactivity recovery and HPLC/radio-detector for metabolite profiling in urine and bile. RESULTS The majority(73.6%)of the administered radioactivity was recovered in the first 24 h postdose with 48.3%in urine and 25.4%in faeces. It was cumulated to(84.7±6.8)%till 168 h. In BDC rats,29.3%of the dose was recovered in the bile 3 d post-dose. According to the peak area ratio determined by HPLC/radio-detector,only 4.7%and 9.5%of the radioactive dose were excreted as the parent drug in urine and bile,respectively,while the majority of the remaining radioactivity was excreted in the form of various metabolites. CONCLUSION Following oral administration in rats,trantinterol is completely absorbed,extensively metabolized and rapidly excreted mainly in urine as various metabolites.
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BACKGROUND:Skeletal muscle satel ite cells are totipotential stem cells with multi-directional differentiation potential, locate in skeletal muscle interstitium, have a certain tolerance to ischemia and hypoxia, and are important cells in stem cellengineering. OBJECTIVE:To establish a thrifty, convenient culture procedure and create a simple, efficient method to transfect skeletal muscle satel ite cells, and investigate genetic expression after the transfection for cellular cardiomyoplasty. METHODS:Skeletal muscle satel ite cells were isolated from rabbit thigh and cultured. Their growth curves were determined by CKK-8 method. Grouped by different proportions of the plasmid and liposome, skeletal muscle satel ite cells were transfered by the enhanced green fluorescent protein plasmid based on liposome. After transfection, the efficiency and character of target genetic expression was determined. RESULTS AND CONCLUSION:Satel ite cells were isolated, cultured and transfected successful y. In suitable ratio of plasmid and liposomes, the transfection efficiency reached up to above 35%. The target protein was expressed within 12 hours after transfection, reached maximum in 48-72 hours and decreased gradual y after one week. The expression stil could be observed two weeks latter. The enhanced green fluorescent protein plasmid conducted by cationic liposome could be transfered into skeletal muscle satel ite cells efficiently. The transfection efficiency was correlated closely to the ratio of plasmid and lipofectamine. The change of target gene expression depended on time.
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Objective To establish an LC-MS/MS method for determination of S-071031 B, a novel antidepressant , in rat plasma and to study its pharmacokinetic profiles .Methods An LC-MS/MS method was established to determine S-071031B in rat plasma, and L-8021 was employed as the internal standard .The analytes were separated on a C18 column with a mobile phase consisting of water-acetonitrile containing 0.1%(v/v) formic acid at a flow rate of 0.3 ml/min.The mass spectrometer was operated in a selected reaction monitoring ( SRM ) mode with a positive electrospray ionization (ESI) interface.The plasma concentration-time curve was drawn and pharmacokinetic parameters were calculated by DAS 2.0.Results The linear range was from 2 to 1000 ng/ml with a sensitivity of 2 ng/ml as the lower limit of quantification . The intra-day and inter-day precisions , recoveries and matrix effects at three spiked levels were all suited to the determina-tion of biological samples.After oral administration of S-071031B, the Cmax of S-071031B was (287.2 ±50.8) μg/L and the Tmax was (0.8 ±0.3) h, with a t1/2of (2.9 ±0.6) h and an AUC(0-∞)of (1372.6 ±255.3) μg/L· h.Conclusion This method is sensitive and specific enough for determination of S-071031 B in rat plasma to facilitate the study of its phar-macokinetics .
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Objective To develop a HPLC-MS/MS method for the determination of aconitine and study thein vitro metabolic stability of aconitine in dog tissue homogenates.Methods The chromatographic separation was performed on a C18 column.The mobile phase consisted of acetonitrile and water with 0.2％ formic acid and 5 mmol/L ammonium acetate.A triple quadrupole tandem mass spectrometer equipped with an electrospray ionization interface source was used for the quantitative determination in the positive selective reaction monitor mode.Aconitine was incubated with dog tissue homogenates and samples were withdrawn at different time points and precipitated by acetonitrile with internal standards citalopram.Results Aconitine showed good linear relationship over the range from 5 to 500 ng/ml.The recoveries of aconitine were between 85.73％ and 92.12％ at three QC concentration levels.The intra- and inter-day precisions were 5.32％ - 8.95％ and 5.45％ - 8.86％,respectively.After incubation,about 20％ of aconitine were cleared in the liver and small intestine,and t1/2 were 460.6 and 521.3 min,respectively.But none was metabolized in the stomach and kidney.Conclusion These results demonstrated that aconitine was mainly metabolized in the liver and small intestine at a slow rate.
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Objective To investigate the role of tissue factor in the occurrence and development of co agulation in acute vascular rejection of heart xenotransplantation. Methods An animal model for acute vascular rejection of heart xenotransplantation was es tablished by using rat as recipient and guinea pig as donor. The xenografts were removed at 4, 8, 12, 16, and 24 h after the operation for fibrin sedimentation by immunohistochemical technique to evaluate coagulation. Meanwhile, the express ion of tissue factor mRNA was detected at different time points by RT-PCR. Hear ts of normal guinea pigs were used as controls. Results Immunohistochemical examination showed that coagu lation developed at the 8 h when interstitial fibrin deposition and fibrinous th rombus appeared and aggravated with time. High expression of guinea pig tissue factor mRNA appeared at 4 h after the transplantation and then steadily d eclined and totally terminated at the 16 h. The expression of rat tissue factor mRNA appeared 16 h post operation and then kept steadily enhanced. Conclusions The tissue factor acts as an important role in the acute vascular rejection of h eart xenotransplantation. The high expression of donor tissue factor mRNA might be related to the trigger of coagulation and the high expression of the receptor ’s tissue factor may be related to the further development of coagulation.
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Objective: This study was designed to determine the expression of IFN-γ mRNA in heart allograft and its correlation to postoperative, cell infiltrating and allograft survival time. Methods: The heterotopic rat heart transplantation model was established with a simplified method, and the allografts and isografts were harvested at 1, 3,5,7,9 and 11 postoperative days. After the total RNA was prepared, the standard primer and target primer were amplified in the same tube, the average ratio of the target products pixel volume to primer's was calculated and a coordinates chart was made. Results: The expression level of IFN-γ mRNA in heart allograft was elevated and its peak was on the fifth postoperative day, and prior to the heart death has a positive correlation with cell infiltrating. Conclusion: IFN-γ may play on important role in postoperative rejection.