1.Effects of Propafenone on Action Potential of Rabbit Ventricular Myocytes and the Use-dependent Block of Transient Sodium Current
Jing LI ; Xiaoyun ZHENG ; Gang ZHOU ; Yuetao ZHAO ; Zhen YANG
Chinese Circulation Journal 2015;(7):679-683
Objective: To study the effects of propafenone on action potential (AP) of rabbit ventricular myocytes with the tonic block and use-dependent block of transient sodium current (INa-T). Methods: A total of 10 adult New Zealand white rabbits were sacriifced and 10 individual ventricular myocytes were isolated by enzyme digestion method. Microelectrode technologies were used to record AP-related parameters: maximum diastolic potential (MDP), maximum rate of rise of the action potential upstroke (Vmax), action potential amplitude (APA) and action potential duration at 20%, 50% and 90% (APD20, APD50 and APD90).INa-T was measured, I-V curves and peak currents at different frequencies were detected by whole cell patch clamp before and after propafenone perfusion at 10 μmol/L. Results: There was no statistical difference in MDP at before and after propafenone perfusion as (-80 ± 6) mV vs (-82 ± 5) mV,P>0.05. After perfusion, APA was signiifcantly decreased as (95 ± 12) mV vs ( 125 ± 10) mV,P<0.05, the Vmax slowed down as (330 ± 43) V/s vs (420 ± 54) V/s,P<0.05, while APD20, APD50 and APD90 were unchanged as (8 ± 2) ms vs (6 ± 2) ms,P>0.05, (16 ± 3) ms vs (12 ± 3) ms,P>0.05 and (86 ± 14) ms vs (85 ± 12) ms,P>0.05. After propafenone perfusion, I-V curve ofINa-T was shifted upward and the peak current was decreased as (3001 ± 383) pA vs (4193 ± 378) pA, P<0.05. Before perfusion, when stimulated at 0.06 Hz, 1 Hz, 2 Hz, 5 Hz and 10 Hz, there were no signiifcant use-dependent block inINa-T , and no real difference inINa-T between the 10th and 1st pulse,P>0.05. After perfusion, no significant use-dependent block was observed when stimulated at 0.06 Hz and 1 Hz,P>0.05, while at 2 Hz, 5 Hz and 10 Hz, propafenone perfusion demonstrated signiifcant use-dependent block uponINa-T with the inhibition fractions of (22 ± 11)%, (38 ± 14)% and (52 ± 17)% respectively, those were signiifcantly different from the inhibition fractions at either 0.06 Hz or 1Hz,P<0.05. When the inhibition fractions were compared by each 2 conditions, allP<0.05. Conclusion: Propafenone may slow down the Vmax of AP, reduce APA and without the impact on APD; the effects onINa-T is not only in tonic block, but also more obviously in use-dependent block in isolated ventricular myocytes of New Zealand rabbit. Such inlfuences minimized the impact on QT interval and meanwhile, decreased the incidence of brad arrhythmia.
2.Decreased expression of γ-aminobutyric acid receptor in the hippocampal tissues of pharmacoresistant temporal lobe epileptic rats
Guofeng WU ; Jing SHI ; Zhen HONG ; Feng ZHOU
Chinese Journal of Neurology 2013;46(10):702-705
Objective To establish a multi-drug resistant model of temporal lobe epilepsy,and to observe the changes of γ-aminobutyric acid (GABA) receptor expression in the hippocampal tissues so as to explore its effects in pharmacoresistant epileptogenesis.Methods One hundred rats were selected to prepare the amygdaloid kindled model of epilepsy by chronic stimulation of amygaloid basal lateral nucleus.After the kindled model of epilepsy was prepared successfully(n =52),pharmacoresistant epileptic rats were selected according to their response to the phenobabital and phenytoin.The selected pharmacoresistant epileptic rats (n =8)were sacrificed and the hippocampus was removed to determine the GABA receptor expression,and the same number of pharmacosensitive epileptic rats was used as control.Results The pharmacoresistant epileptic rats displayed degenerative and necrotic hippocampal neurons.The arrangement of hippocampal neurons was disordered,and the structural characteristics of the arrangement of the hippocampal neurons disappeared.The gray values of GABAA-positive neurons in the hippocampal tissues (141.15 ± 14.72) increased significantly compared with the pharmacosensitive epileptic rats (92.56 ± 5.17; t =3.380,P =0.006).Western blot method demonstrated that the band of GABAA became narrowed and thin.The relative quantity of GABAA in the hippocampal tissues (0.38 ± 0.08) decreased significantly as compared with the pharmacosensitive epileptic rats (0.88 ± 0.18).A significant difference was observed (t =5.420,P =0.002).Conclusions GABA receptor expression might be decreased in the hippocampal tissues of pharmacoresistant epileptic rats.It might play a certain role in the formation of pharnmacoresistant epilepsy.
3.Analysis of TGFBI gene mutation in a Chinese family with Avellino corneal dystrophies
Zhi-qiang, HOU ; Wei, WANG ; Jing, ZHANG ; Yong-gen, XU ; Zhen, ZHOU ; Jing, HAN ; Chen, HUANG
Chinese Journal of Experimental Ophthalmology 2011;29(3):254-257
Background Researches demonstrated that corneal dystrophy is associated with the mutation of transforming growth factor beta induced gene(TGFBI)located at chromosome 5q31 domine.Recent study showed that the gene mutation location is in R124H of TGFBI gene. Objective This study was to identify the mutation characteristics of TGFBI gene in a Chinese family with Avellino corneal dystrophy. Methods This Chinese family with Avellino corneal dystrophy were determined and surveyed in Peking University Third Hospital.Periphery blood from 8 patients with Avellino corneal dystrophy and 2 unaffected subjects were collected from a Chinese family with corneal dystrophy for the extraction of DNA.Exons 4,11,12 of the TGFBI gene were amplified by polymerase chain reaction(PCR),and the amplified products were sequenced directly and compared the gene sequence with that of TGFBI in GenBank.Written informed consent was obtained from each Subject prior to any medieal process. Results This family included 27 members of consecutive 4 generation.The hereditary pattern W88 in accordance with the autosomal dominant inheritance.Directly sequencing of 8 affected members revealed a G tO A transition at codon 124 (CGC to CAC),producing R124H mutation of TGFBI gene.Two synonymous single nucleotide polymorphism(SNP)of TGFBI gene occurred in the family.including a C to T transition at eodon 472(CTC to CTT)in 8 members,and a T to C transition at codon 540(TTT>TTC)in 9 members,which wag unrelated with disease. Conclusion R124H mutation of the TGFBI gene is found in this Chinese family with Avellino corneal dystrophy.
4.The prevention and treatment of unstable bladder after suprapubic prostatectomy by capsaicin instilled into the bladder combined with patient-controlled epidural analgesia
Hanguo JING ; Ruji SHI ; Zhen CHENG ; Huiqiu YAN ; Tengchun WANG ; Yusheng JLNG ; Lizhi HUO ; Yuxia ZHOU
Chinese Journal of Postgraduates of Medicine 2008;31(23):24-26
Objective To explore the effect of the prevention and treatment of unstable bladder after suprapubic prostaectomy by capsaicin instilled into the bladder preoperatively combined with patient-controlled epidural analgesia(PCEA)for benign prostatic hyperplasia(BPH).Methods Sixty patients with BPH underwent suprapubic prostatectomy under epidural anesthesia were randomly divided into control group (30 cases)and treatment group(30 cases),100 ml of 100 μmol/L capsaicin was instilled into the bladder preoperatively for 30 minutes combined with PCEA after operation in treatment group,the control group was only given PCEA.Observed the incidence and continuous time of unstable bladder after operation in two groups.Results Unstable bladder was found in 3 cases of treatment group and they were Ⅰdegree,12 cases happened unstable bladder in control group,3 cases Ⅰdegree,5 cases Ⅱdegree,3 cases Ⅲ degree,1 case Ⅳ degree.There was obvious significance between two groups (P<0.05).Conclusion Capsaicin instilled into the bladder combined with PCEA can cut off the reflex arc of detrusor contraction more completely and has obvious effect of decrease the incidence of unstable bladder after suprapubic prostatectomy and can be used widely.
5.Rapamune and Tacrolimus improve renal function significantly in chronic allograft nephropathy
Jing LIU ; Delin GUAN ; Zhen HUANG ; Jianchen WU ; Yong ZHAO ; Su ZHOU
Chinese Journal of Urology 2008;29(8):538-540
Objective To discuss the efficacy of application combination Of minimal immunosuppressive drugs in chronic allograft nephropathy after renal transplantation. Methods Data were drawn from the First Hospital of Tsinghua University.From September 1,2004 to July 1,2006,31 cadaver kidney transplantations were performed using triple immunosuppression with tacrolimus(n=31)and MMF plus steroids before using new strategy.The new strategy is Rapamycin+tacrolimus+MMF+Prednisone.The serum ereatinine,GFR(ml/min/1.73 m2)and 24-hours urine protein before and after 12 months of using lOW dose combination of calcineurin inhibitors,MMF,Rapamune,Predsone and Q80 were recorded.During this time,the concentration of tacrolimus,rapamune were monitored as well. Results After 12 months follow-up,the serum creatinine of 28 patients were decreased from(300±21)μmol/L to(215±38)μmol/L.GFR(ml/min/1.73m2)was elevated from 42.54±2.95 to 49.98±3.05.Three patients whose serum creatinine was 416-464μmol/L had to take hemodialysis.The 24-hours urine protein(g)of 31 patients below 0.8 g did not increase urine protein during follow-up.One patient's 24-hours urine protein(g)increased from 0.95 to 1.29.The patient and graft survival rate was 100%(31/31),90.3%(28/31)respectively.The rapamune main side effect was hyperlipidemia. Conclusions Rapamune and low dose Tacrolimus+Myeophenolate Mofetil+Corticosteroid could be a safe treatment.It may improve renal function in chronic allograft nephropathy.
7.Effects of total flavonoids of propolis on apoptosis of myocardial cells of chronic heart failure and its possible mechanism in rats.
Hai-hua WANG ; Jin ZENG ; Hai-zhen WANG ; Yu-xin JIANG ; Jing WANG ; Ping-ping ZHOU
Chinese Journal of Applied Physiology 2015;31(3):201-206
OBJECTIVETo investigate the effects of total flavonoids of propolis (TFP) on apoptosis of myocardial cells of chronic heart failure and its possible mechanism in rats.
METHODSSix male SD rats were randomly selected as normal control group, the remaining rats were made as chronic heart failure (CHF) model by intraperitoneal injection of adriamycin. The rats in the successful model were randomly divided into five groups (n = 6): CHF group, total flavonoids of propolis low dose group (LD group), total flavonoids of propolis middle dose group (MD group), total flavonoids of propolis high dose group (HD group), digoxin group (DIG group). After six week treatment, cardiac function indexes of rats were recorded by signal acquisition system; brain natriuretic peptide (BNP), cardiac troponin I (cTnI), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) content in plasma were detected; Myocardial morphological changes and collagen fiber hyperplasia by HE and Masson staining were observed; Myocardial apoptosis was detected with TUNEL method and protein connexin 43(P-Cx43) expression was detected by Western blot method.
RESULTSCompared with NC group, left ventricular systolic pressure(LVSP) and maximal rise/fall velocity of left ventriculad pressure (± dP/dt(max)) absolute value in CHF group were significantly lowered (P < 0.01) while left ventricular end diastolic pressure (LVEDP) was increased significantly (P < 0.01); Contents of plasma BNP, cTnI, TNF-α and IL-6 in the CHF group were significantly improved (P < 0.01). Compared with CHF group, LVSP, ± dP/dt(max) absolute value in MD and HD groups were increased (P < 0.05), and LVEDP was significantly lowered (P < 0.01); LVEDP in LD group was significantly lowered (P < 0.01), changes in LVSP and ± dp/dt(max) absolue value were not obvious (P > 0.05). BNP, cTnI, TNF-α and IL-6 contents in MD and HD groups were significantly reduced (P < 0.01), but those plasma indicator changes were not obvious in LD group (P > 0.05). Western blot showed that P-Cx43 expression in CHF group was significantly higher than that in NC group (P < 0.01) and that in all TFP treatment groups it was decreased compared with CHF group (P < 0.05, P < 0.01), among which pairwise comparisons also showed differences (P < 0.05), myocardial apoptosis index (%)(22.62 ± 3.39) in CHF group was higher than that in NC group( 1.12 ± 0.24) (P < 0.01); compared with CHF group, the apoptosis index of myocardial cells (%) in LD,MD and HD groups, (15.79 + 2.8), (9.28 + 2.1) and (4.73 + 1.14) respectively, were significantly lower than those in the CHF group( P < 0.01). The expression level of P-Cx43 positively correlated with the apoptotic index (r = 0. 861, P < 0.01).
CONCLUSIONTotal flavonaids of propolis have inhibitory effect on apoptosis of myocardial cells of chronic heart failure induced by adriamycin in rats, and the mechanism may be closely related to the regulation of Cx43 expression, especially the regulatory phosphorylation status.
Animals ; Apoptosis ; Chronic Disease ; Connexin 43 ; metabolism ; Disease Models, Animal ; Doxorubicin ; adverse effects ; Flavonoids ; pharmacology ; Heart Failure ; drug therapy ; Interleukin-6 ; blood ; Male ; Myocardium ; pathology ; Myocytes, Cardiac ; drug effects ; Natriuretic Peptide, Brain ; blood ; Phosphorylation ; Propolis ; chemistry ; Rats ; Rats, Sprague-Dawley ; Troponin I ; blood ; Tumor Necrosis Factor-alpha ; blood
8.Effect of Modified Danggui Yinzi on Delayed Allergy in Model Mice with Qi-Blood Deficiency Syndrome.
Xu-rui WANG ; Ce ZHOU ; Zhen-dong ZHONG ; Qu DUAN ; Ai-yuan DU ; Guo JING
Chinese Journal of Integrated Traditional and Western Medicine 2016;36(3):345-347
OBJECTIVETo explore the effect of Danggui Yinzi (DY) on delayed allergy in model mice with qi-blood deficiency syndrome (QBDS).
METHODSQBDS model was established in 48 Kuming mice of SPF grade by using reserpine and acetophenone hydrazine. Forty of them were then randomly divided into the model group, the loratadine group, the high dose DY group, the middle dose DY group, and the low dose DY group, 8 in each group. Another 8 in line with the same standard were recruited as a blank group. Mice in high, middle, and low dose DY groups were administered with DY concentrated solution at 60, 30, 15 g/kg by gastrogavage. Mice in the loratadine group were administered with loratadine solution at 1.66 mg/kg by gastrogavage. Equal volume of normal saline was administered to mice in the model group and the blank group by gastrogavage. All medication was given once per day for 1 successive week. Except those in the blank group, the rest mice were evenly smeared with 1% DNCB solution on the abdomen. Five days after skin allergy, 1% DNCB solution was smeared to right ear of all mice to stimulate allergic reaction. Mice in the blank group were smeared in the same way without allergenic reaction. The auricle swelling and the inhibition ratio were determined at 24 h after attack. Blood was collected from orbit and serum IgE level detected using double-antibody sandwich ELISA.
RESULTSCompared with the blank group, auricle swelling obviously increased and serum IgE level was obviously elevated in the model group (P < 0.01). Compared with the model group, auricle swelling obviously decreased and serum IgE level was obviously reduced in the 3 dose DY groups (P < 0.05, P < 0.01). Meanwhile, the auricle swelling degree was superior in high and middle dose DY groups to that in the loratadine group (P < 0.05). The inhibition ratio of auricle swelling was sequenced from high to low as 67.3% in the high dose DY group, 56.0% in the middle dose DY group, 48.1% in the low dose DY group, 47.3% in the loratadine group.
CONCLUSIONSDY could inhibit auricle swelling and lower serum IgE level. It also could inhibit delayed allergic reaction in model mice with QBDS to some extent.
Animals ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Edema ; drug therapy ; Hypersensitivity, Delayed ; drug therapy ; Immunoglobulin E ; blood ; Loratadine ; pharmacology ; Mice ; Qi ; Random Allocation
9.Establishment and evaluation of a rhesus monkey model of experimental type 2 diabetes mellitus
Qiaoqiao SONG ; Huiliang ZHOU ; Haitao ZHEN ; Na WANG ; Jing DENG ; Jinxiang WANG ; Xinghua PAN
Chinese Journal of Tissue Engineering Research 2016;20(40):6048-6053
BACKGROUND:At present, there are few reports about the non-human primate models of type 2 diabetes mel itus in domestic and abroad, so it lacks of standardized production methods and evaluation criteria.
OBJECTIVE:To establish a safe and effective type 2 diabetes mel itus model of rhesus monkey and evaluation method.
METHODS:Twelve rhesus monkeys were randomly assigned to experimental group (n=9) and control group (n=3). Rhesus monkeys in the experimental group were fed with high-glucose and high-fat diet for 4 weeks, and intraperitoneal y injected with 30 mg/kg streptozotocin to establish models of type 2 diabetes mel itus. Rhesus monkeys in the control group were fed with an equal volume of physiological saline. At 12 weeks after injection, peripheral blood serum was col ected to measure fasting blood glucose, lipids, insulin, and C-peptide levels. Intravenous glucose tolerance test and C-peptide release test were used to detect pancreatic gland and pancreatic islet function. Histopathological examination was performed in pancreas, kidney and liver.
RESULTS AND CONCLUSION:(1) 12 weeks after injection, fasting blood glucose, triglycerides, and total cholesterol levels were significantly higher in the experimental group than in the control group (P<0.05). Insulin and C-peptide levels were significantly lower in the experimental group than in the control group (P<0.05). (2) The area under the curve for intravenous glucose tolerance test was increased in the experimental group than in the control group (P<0.05). The area under the curve for C-peptide response test was significantly reduced in the experimental group than in the control group (P<0.05). (3) The pathological sections of pancreas, kidney and liver showed typical pathological changes of diabetes in the experimental group. (4) It is confirmed that we got high achievement about rhesus monkey models of type 2 diabetes mel itus made by high-glucose and high-fat diet combined with low-dose streptozotocin. It is a feasible, safe and effective method.
10.Effect of monosialoganglioside GM1 on cardiopulmonary bypass-induced inflammatory response in rats
Huijuan CAO ; Zhen ZHANG ; Tiezheng ZHANG ; Hongqian WANG ; Jin ZHOU ; Jing YAO
Chinese Journal of Anesthesiology 2013;(1):119-122
Objective To investigate the effect of monosialoganglioside GM1 on cardiopulmonary bypass (CPB)-induced inflammatory response in rats.Methods Twenty-four adult male Sprague-Dawley rats,weighing 350-450 g,were randomly divided into 3 groups (n =8 each):sham operation group (group S),group CPB and CPB + GMi group (group G).GM1 20 mg/kg was added to the priming solution in group G.While the equal volume of normal saline was given in group CPB.Blood samples were collected from the jugular vein at 3 h after termination of CPB for determination of plasma concentrations of neuron-specific enolase (NSE) and S-100β protein (by ELISA) and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) (by radioimmunoassay).The hippocampi were isolated to detect the expression of hippocampal matrix metalloproteinase-9 (MMP-9) and IL-10 and NF-κB activity in hippocampal tissues by Western blot.Results Compared with group S,the plasma concentrations of NSE,S-100β protein,TNF-α and IL-6 and NF-κB activity were significantly increased,the expression of MMP-9 was up-regulated,and the expression of IL-10 was down-regulated in groups CPB and G (P < 0.05).Compared with group CPB,the plasma concentrations of NSE,S-100β protein,TNF-α and IL-6 and NF-κB activity were significantly decreased,the expression of MMP-9 was down-regulated,and the expression of IL-10 was upregulated in group G (P < 0.05).Conclusion The mechanism by which GM1 reduces the CPB-induced brain damage may be related to reduction of the central and systemic inflammatory response in rats.