1.Effects of propofol and thiopental on calcium and potassium channel currents in rat ventricular myocytes
Ying ZHANG ; Xinliang ZHUANG ; Shitong LI
Chinese Journal of Anesthesiology 1996;0(09):-
Objective To evaluate the effects of propofol and thiopontal on calcium and potassium channels in rat ventricular myocytes and to elucidate the underlying mechanisms of their inhibitory effect on myocardium. Methods Freshly isolated ventricular myocytes were prepared from hearts of rats by trypsin. The effects of propofol and thiopental on L-type calcium current(Ica) and delayed rectifier potassium current(IK)were compared using whole-cell patch clump technique. Results Propofol and thiopontal produced a concentration-dependent inhibition of Ica. Peak concentration of propofol(50 ?mol?L~(-1)) and thiopental(100 ?mol?L~(-1)) during induction of anesthesia decreased Ica by 28% and 46% and shifted the steady-state inactivation curve to more negative voltage, but had no effect on the steady-state activation curve. Propofol and thiopental also decreased IK in a concentration-dependent manner, but the effects of both anesthetics on IK were smaller compared with their effects on Ica. Conclusion The findings of this study suggest that the negative inotropic of propofol and thiopental are, at least in part, related to decrease in Ca~(2+) trans-sarcolemmal current by accelerating L-type calcium channel inactivation. Both anesthetics decrease delayed rectifier potassium current, thus partially antagonizing the effect of decreased calcium current.
2.Effect of sevoflurane on expression of calcium-sensing receptor in myocardium of rats with high-level spinal cord injury
Chao GONG ; Xiaoni ZHANG ; Shitong LI
Chinese Journal of Anesthesiology 2015;35(7):879-882
Objective To evaluate the effect of sevoflurane on the expression of calcium-sensing receptor (CaSR) in the myocardium of rats with high-level spinal cord injury (SCI).Methods Thirty healthy male Wistar rats, weighing 250-300 g, were randomly divided into 3 groups using a random number table: sham operation group (group S, n = 6) , SCI group (n =12) and sevoflurane group (group Sev).SCI was induced in anesthetized rats by dropping a l0-g weight onto C7 spinal cord from 5.0 cm height falling freely inside a vertical hollow glass tube.Group SCI inhaled 2 L/min pure oxygen for 30 min, and group Sev inhaled 2% sevoflurane for 30 min starting from 30 min after SCI.At 12 and 24 h after SCI (T1,2) , 6 rats were selected randomly, and blood samples from the abdominal aorta were drawn for determination of serum cardiac troponin I (cTnI) concentrations.The rats were then sacrificed, and myocardial specimens were obtained for determination of CaSR protein and mRNA expression (using fluorescent quantitative real-time reverse transcriptase-polymerase chain reaction or Western blot) and for examination of myocardial ultrastructure (with transmission electron microscope).Results Compared with group S, the serum cTnI concentrations and CaSR protein and mRNA expression were significantly increased at T1,2 in SCI and Sev groups.Compared with group SCI, the serum cTnI concentrations and CaSR protein and mRNA expression were significantly decreased at T1,2 in Sev group.The damage to myocardial cells was significantly reduced in group SCI compared with group Sev.Conclusion Sevoflurane reduces myocardial damage through inhibiting CaSR expression in the myocardium of rats with high-level SCI.
3.Specific antibody to calpain induces schistosomulicidal activity of Schistosoma japonicum in vitro
Kun LIU ; Renli ZHANG ; Shitong GAO
Chinese Journal of Infectious Diseases 2001;0(06):-
Objective To explore the efficacy and protective mechanism of calpain, a calcium activated neutral proteinase as a vaccine candidate molecule. Methods Anti calpain sera were prepared by immunized BALB/c mice with recombinant calpain. Anti calpain sera, schistosomula of Schistosoma japonicum , and mouse eosinophils were incubated at 37 ?C , 5% CO 2 for 48 hours, and the adherence of eosinophils to schistosomula and its schistosomulacidal efficacy were observed. Results Mice immunized with recombinant calpain produced a high level IgG antibodies specific to the antigen immunized. Immunoblotting analysis showed murine anti recombinant calpain sera bound specifically to recombinant calpain. Ninety six percent of schistosomula were surrounded by cells when incubated with mouse eosinophils, and a significant number of dead schistosomula was observed at 48 hours when incubated with mouse serum and eosinophils as compared with control serum and eosinophils ( P
4.The role of p38 signal transduction pathway in the pathogenesis of Barrett esophagus
Shitong ZHANG ; Wenyuan BAI ; Junji MA ; Helin ZHANG ; Xianli MENG
Chinese Journal of Digestion 2012;32(8):539-542
Objective To investigate the role of deoxycholic acid (DCA) in the pathogenesis of Barrett esophagus.Methods Normal human esophageal mucosal epithelial cells were cultured in vitro with defined keratinocyte serum-free media (D-KSFM).The cultured cells were treated with different concentrations of DCA and specific p38 mitogen activated protein kinase (MAPK) inhibitor. The expression of p38,phosphorylated p38 (p-p38) and caudal-related homeodomain transcription 2 (CDX2) at protein level were assessed by Western blot.The correlation between p-p38 and CDX2 was analyzed.The data were analyzed by one way ANOVA and LSD test.Results After being cultured with DCA for 24 h,the expression of p-p38 and CDX2 increased along with the increasing of DCA concentration.Compared with the control group (p-p38 was 13.7% ± 1.0% and CDX2 protein was 0),the difference was statistically significant (P< 0.05).When DCA was at 500 μmol/L,the expression of p-p38 and CDX2 reached the highest level (44.0% ± 1.7% and 8.59± 1.25).After pretreated with SB203580 for two hours and then 500 μmol/L DCA was added into cell culture,both expression level of p-p38 and CDX2 decreased compared with 500μmol/L DCA group (p-p38:28.3% ±2.2% vs50.5%±9.5%,CDX2:0.94±0.13 vs 2.31±0.41) after 24 h.Conclusions DCA can induce the expression of CDX2 in normal human esophageal mucosal epithelial cells,which is related with the activation of p38.The phosphorylation of p38 maybe involved in the pathogenesis of Barrett esophagus.
5.Species identification of freshwater snail Planorbella trivolvis and analysis of its potential distribution
Xiaoheng LI ; Shitong GAO ; Wenbiao GU ; Yi ZHANG ; Yunhai GUO
Chinese Journal of Schistosomiasis Control 2015;(3):268-272
Objective To identify the species classification of an ornamental Planorbidae from a flower market in Shanghai and analyze its potential distribution in China. Methods In August 2013,six freshwater snail specimens were collected from the Wanshang flower market. The species was identified by morphology and molecular biology. An ecological niche model was constructed based on the native geographic presence occurrence data,and projected onto the whole of China to predict the poten?tial distribution. Results Their shell external morphology suggested that the specimens belonged to Planorbella trivolvis(Say 1817)of Planorbidae,which is native in North America. The sequence data of a fragment of the mitochondrial cytochrome c oxi?dase subunit I(COI)confirmed its identification. A total of 2 294 georeferenced occurrence points in North America were car?ried out from the Global Biodiversity Information Facility databases and 614 records with coordinates were used to produce a North American native niche model by a maximum entropy method(Maxent). The projection on China results suggested high probabilities of occurrence mostly in Henan Province and its borderland with nearby provinces. Conclusions P. trivolvis is sim?ilarly with Biomphalaria species from shell morphology. It is the first records of the species in China,and the field dispersal is not clear.
6.Effects of acute peritonitis on rocuronium-induced neuromuscular blockade in abdominal muscles and function of sarcoplasmic reticulum of rats
Jianyou ZHANG ; Shitong LI ; Yuan GONG ; Meirong YANG ; Jin WU
Chinese Journal of Anesthesiology 2016;36(9):1118-1121
Objective To evaluate the effects of acute peritonitis on rocuronium?induced neuromus?cular blockade in abdominal muscles and function of the sarcoplasmic reticulum of rats. Methods Thirty?six pathogen?free male Sprague?Dawley rats, weighing 220-250 g, were divided into 2 groups using a ran?dom number table: control group (group C, n=12) and acute peritonitis group (group P, n=24). After the rats were anesthetized with pentobarbital sodium, acute peritonitis was induced by artificial gastric per?foration in group P. At 1 and 2 h after operation, the changes in the intra?abdominal pressure (IAP) with different volumes were detected, and blood samples were collected from the orbital veins for determination of serum levels of interleukin?6, tumor necrosis factor?alpha and interleukin?13. Rocuronium 3. 5 mg∕kg was then injected via the caudal vein. The IAP was recorded at 1, 5 and 10 min after administration. The intra?cellular free Ca2+ concentration was assessed using fura?2, and the maximal Ca2+ uptake and release rate in the sarcoplasmic reticulum were calculated. Results Compared with group C, the serum levels of interleu?kin?6 and tumor necrosis factor?alpha at 2 h after operation and IAP at 1 and 2 h after operation were signifi?cantly increased, the IAP was increased at 1, 5 and 10 min after administration of rocuronium, and the maximal Ca2+ uptake rate and amount of calcium uptake in the sarcoplasmic reticulum were decreased in group P ( P<0.01) . Conclusion Acute peritonitis decreases rocuronium?induced neuromuscular blockade in abdominal muscles, which may be related to the impaired Ca2+uptake function of the sarcoplasmic reticu?lum of rats.
7.Effects of Ketamine on Ca2 + Transsarcolemmal Influx in Isolated Rat Ventricular Mycocytes
Ying ZHANG ; Shitong LI ; Xinliang ZHUANG ; Jichang LI
Fudan University Journal of Medical Sciences 2001;28(1):61-62,65
Purpose To investigate the effects of different concentration of ketamine on Ca2 transsarcolemmalinflux induced by KCl in isolated rat ventricular myocytes. Methods Freshly isolated rat ventricular nyoeyteswere loaded with Fluo-3AM, a Ca2 + indicator. The effects of different concentration ketamine( 1 × 10- s, 1 × 10- 4,1 × 10-3 mmol/L) on the change of intracellular Ca2+ concentration induced by KCl were investigated. ResultsLow concentration ketamine(1 × 10-5 mrnol/L) did not change Ca2+ transsarcolemmal influx. Although mediumeoncentration ketamine( 1 × 10-4 rmol/L) made the influx slower, the eventual peak concentration of intracellularCa2+ had no difference from that of the control group. The high concentration ketamine (1 × 10-3 mmol/L) inhibited Ca2-1 influx,intracellular Ca2+ fluorescent intensity decreased about 13.2% (P<0.05). ConclusionsKetamine inhibits Ca2 + trranssarcolemmal influx in isolated rat ventricular myocytes dosedependently, which may inpart explain its negative inotropic effect.
8.Apoptin induces G_2-M arrest in cancer cells
Xiangjun HE ; Shitong SHANG ; Yujing LIU ; Qi ZHANG ; Shenwu WANG
Journal of Peking University(Health Sciences) 2004;0(03):-
Objective: To further study the effect of apoptin in inducing cancer cell specific apoptosis and the possible applications in cancer therapy. Methods: Apoptin gene was amplified by PCR and inserted into pcDNA3.1(+) with a FLAG tag in front of the multi-cloning-site. Apoptin gene with the FLAG tag was sub-cloned into an adenovirus vector. Several cancer cell lines were transfected with pcDNA3. 1/FLAG/apoptin or infected with apoptin containing recombinant adenoviruses to study the morphologic changes. Ad/apoptin infected cells were also analyzed by flowcytometry after staining with PI. Results: Expressed apoptin was localized in the nucleus of cancer cells. Chromatin condensation occurred 2 or 3 days after Ad/apoptin(+) infection. Cell number in G 2-M phase increased dramatically after Ad/apoptin(+) infection. Conclusion: Apoptin can induce cell cycle G 2-M arrest and chromatin condensation in cancer cells.
9.The effects of propofol and thiopental on Ca~(2+) mobilization in cultured rat ventricular myocytes
Ying ZHANG ; Xinliang ZHUANG ; Shitong LI ; Guohui XU ;
Chinese Pharmacological Bulletin 1986;0(04):-
AIM To elucidate the direct effects of propofol and thiopental on cardiac contraction by measuring intracellular Ca 2+ concentration change in cultured rat ventricular myocytes. METHOD Ventricular myocytes of neonatal rats were obtained by enzymatic digestion with typsin and were cultured for 4~5 days, then were loaded with Fluo 3AM, a new Ca 2+ indicator. The effects of propofol (50, 250 ?mol?L -1 ) or thiopental (100, 500 ?mol?L -1 ) on changes of intracellular Ca 2+ fluorescent intensity induced by KCl, isoprenaline or caffeine were investigated. RESULTS Both intravenous anesthetics caused dose dependent inhibit Ca 2+ transsarcolemmal influx induced by KCl and isoprenaline, peak Ca 2+ fluorescent intensity decreased. The inhibitory effect of thiopental was more than propofol at equiopotency. Neither anesthetics altered the amount of Ca 2+ release from intracellular stores in response to caffeine. CONCLUSION The negative inotropic effects of propofol and thiopental, at least in part, may be mediated by a decrease Ca 2+ transsarcolemmal influx though voltage gated and receptor gated calcium channel, but it is not relate to sarcoplasmic reticulum Ca 2+ release.
10.Changes of varicosis and hemodynamics in cirrhotic patients with portal vein hypertension after Hassab devascularization
Yingjian ZHANG ; Jiansheng LI ; Ping WANG ; Jianjun JIN ; Shuangqin ZHAO ; Shitong ZHANG ; Yanli BAI ; Yufeng ZHENG
Chinese Journal of Digestive Endoscopy 2010;27(10):518-521
Objective To analyze the changes of varicosis and hemodynamics in cirrhotic patients with portal vein hypertension at different stages after Hassab devascularization, and to evaluate the outcome.Methods Hassab devascularization was performed in 161 patients with portal vein hypertension, who were all evaluated by means of endoscopy, Doppler color imaging and Child-Pugh grading before and 6, 12, 18,24 months after the procedure, respectively.Results The rates of mild esophageal varicosis were 44.0%,34.8% and 28.3% at 6, 12 and 18 months after Hassab devascularization, respectively, which were all significantly higher than that before the operation(7.5%, P < 0.05), while the rates of severe esophageal varicosis were 25.2%, 29.7% and 34.9% at 6, 12 and 18 months after the procedure, which were significantly lower than that before(65.2%, P < 0.05).The incidence of varices in gastric fundus was correlated with the severity of esophageal varices.At 12 months after the operation, the inner diameters of portal vein and its right branch significantly decreased when compared with those before(P < 0.05), the maximal flow rate,volume of portal vein and average flow rate of the left branch also significantly decreased(P < 0.05).At 6 months after the operation, the average flow rate of the right branch slowed down(P < 0.05).Child-Pugh Grade A accounted for 63.5%, 60.6% and 57.9% at 6, 12 and 18 months after the operation, respectively, which were significantly higher than that before(48.4%, P <0.05).When evaluated at 24 months after the procedure, all variables were getting close to those before.Conclusion The severity of esophageal varices mitigates in 18 months after Hassab.Hemodynamics of portal vein system decreases in 12 months.The overall liver function improves in 18 months after the operation.