Ventricular vulnerable period (VVP) and veniricular fibrillation thre-sheld (VFT) and other electrophysiological items were measured simultaneously with S_1-S_2programmed electrical stimulation. The results showed that during early period of acutemyocardial infarction (AMI) VVP prolonged greatly, VFT decreased remarkably, pacingthreshold decreased, effective refractory period (ERP) shortened, strength interval curve(SIC) shifted downward, the outside of VVP extended to T wave, coupling-interval wasnegatively correlated with echo-interval. The results indicated that myocardial vulnerabi-lity during early period of AMI increased and ventricular arrhythmias were mainly causedby reentry.

0.05). Both of them inhibited the activation of NF-?B. Conclusions Both captopril and irbesartan can be used for the secondary prevention of coronary heart diseases. Especially used for those who can not tolerant the side effects caused by other ACEI drugs.

Objective Objective To investigate the effects of losartan on neointimal proliferation and macrophage count in neointima.Methods The rabbits underwent abdominal aorta balloon de-endothelialization,then received a 1 5 % cholesterol diet for 8 weeks.Abdominal aorta atherosclerosis model was performed in 16 rabbits.Immediately after operation, losartan was orally administered to the rabbits of the losartan group (10mg?kg -1 ?day -1 ), while the rabbits of the control group were given normal saline. Four weeks later the animals were killed and the excised artery segments were prepared for histomorphological observation and macrophages were investigated by immunohistochemistry analysis.Results Compared with the control group, the IT/MT ratio and IA/MA ratio of the losartan group were significantly reduced(P

BACKGROUND: Hypertension is one of the most important risk factors for stroke, and brain focal renin-angiotensin system has been proved to play a vital role in the development of hypertension and stroke.OBJECTIVE: To observe the influence of long-term administration of losartan, an angiotensin-1 receptor antagonist, on the incidence of strokeprone spontaneous hypertension in rats.DESIGN: Randomized controlled experiment.SETTING: Renmin Hospital Affiliated to Wuhan University.MATERIALS: This experiment was carried out in Wuhan University between July 1999 and March 2001. Totally 26 six-week-old male rats with stroke-prone spontaneous hypertension and 8 Kyoto male Wistar rats were recruited in this experiment with the body mass of 144.5-182.1 g.METHODS: Totally 26 six-week-old male rats with spontaneous hypertension were randomized into stroke-Rrone spontaneous hypertension group (n=9) which received gastric perfusion of physiological saline at a dosage of 5 mL/d; losartan 10 mg/(kg·d) group of 9 rats which received gastric perfusion of losartan at a dosage of 10 mg/(kg ·d) and losartan 30 mg/(kg ·d)group of 8 rats which received gastric perfusion of losartan at a dosage of 30 mg/(kg·d). Rats in the three groups were provided with high-protein feed when entering the group, and drank 15 g/L salty water (5 mL/d) from the onset of week 2. At the same time, 8 six-week-old male Wistar rats were taken as normal controls to receive gastric perfusion of physiological saline at a dosage of 5 mL/d once a day; they took ordinary feed and drank running water. All rats lived with 12 hours' day-night alternation at room temperature of 18-20 ℃ and with humidity of 40%-50%. Totally 18weeks later, the incidence of stroke and BP changes were observed. The clinical manifestation of stroke was scored 1 if rats appeared few activities,with movements slightly reduced or excited; 2 score referred to very few activities, with movements obviously reduced or violently stimulated; 3score referred to inability to walk, lying motionless with melancholy symptoms; score 4 referred to paralysis and inability to stand, lateral or bilateral limb paralysis. Transmission electron microscope was used for histological observation of cell apoptosis in the brain.MAIN OUTCOME MEASURES: ① Observation of brain structure at week 18 when rats were decapitated. ② Results of nerve cell apoptosis detected with TUNEL technique. ③ Rat body mass, BP, as well as the incidence and changes of stroke were recorded.RESULTS: Totally 34 rats entered the result analysis. ① The incidence of stroke in the three groups: It was 100%, 22%, and 13%, respectively, in stroke-prone spontaneous hypertension group, losartan 10 mg/(kg·d) group,and losartan 30 mg/(kg·d) group. ② Score for stroke: The score was remarkably higher in stroke-prone spontaneous hypertension group than in losartan 10 mg/(kg·d) group and losartan 30 mg/(kg·d) group [(3.50±0.55,0.67±1.12, 0.38±0.74) minutes]. ③ Electron-microscopic observation: In stroke-prone spontaneous hypertension group, electron density was found increased in necrotic neurons; moreover, some nuclear membrane lost double-layer structure with ridges broken, even reduced or disappeared, displaying vacuolated changes. In losartan 30 mg/(kg·d) group and losartan 10 mg/(kg·d) group, most of neurons displayed basically normal morphology, with neuron chromatin evenly distributed and nuclear envelops regular, but there were still some neurons that had dense chromatin, with ridges broken and reduced. ④ Nerve cell apoptosis in the three groups: It was found obviously lower in normal group than in losartan 30 mg/(kg ·d)group, losartan 10 mg/(kg·d) group, and stroke-prone spontaneous hypertension group [(2.5±0.8, 13.9±4.3, 14.0±4.4, 52.0±16.7)%, P ＜ 0.05]. ⑤ BP changes: At week 18, BP was obviously lower in normal group than in losartan 30 mg/(kg·d) group, losartan 10 mg/(kg·d) group and strokeprone spontaneous hypertension group [(120.1±7.9, 169.4±10.1,216.7±8.3,225.5±6.8) mmHg (1 mm Hg=0.133 kPa), P ＜ 0.05]. ⑥ Changes of body mass: At week 18, body mass was obviously higher in normal group than in losartan 30 mg/(kg·d) group, losartan 10 mg/(kg·d) group, and stroke-prone spontaneous hypertension group [(313.3 ±10.1, 270.8 ± 10.4,258.7±12.7, 231.0±6.5) g, P ＜ 0.05].CONCLUSION: Losartan can obviously reduce the incidence of stroke and nerve cell apoptosis in rats with spontaneous hypertension, suggesting that losartan as an angiotensin-1 receptor antagonist may prevent and delay the onset of stroke through antagonizing angiotensin I receptor, thus exerting brain-protecting function.

Objective To investigate the preventive effects of AT1 receptor antagonist Lorsartan on blood pressure and stroke in spentaneously hypertensive stroske prone rat (SHRsp). Methods Twenty six 6 week aged SHRsp were divided into Losartan 30 mg/kg/d group (n=8), Losartan 10 mg/kg/d group (n=9) and normal saline group (n=9), and 8 sex and age matched Wistar Kyoto(WKY ) as control group (n=8). SHRsp were subjected to 1 5% saline solution as intake and administered 30 mg/kg/d Losartan or 10 mg/kg/d Losartan or equal volume of 0 9% saline solution for 18 weeks by gavage, respectively. The systolic blood pressure was measured by tail cuff sphygmomanometry and clinical score of stroke and survival time of SHRsp were recorded. The coronal brain sections was examined by microscope and electron microscope after decapitation. Apoptosis was analyzed by TdT mediated dUTP biotin nick end labeling and image analysis system. Results Losartan 10mg/kg/d showed no affect on systolic blood pressure but it prevented the occurrence of stroke. The clinical scores of stroke in Losartan 30 mg/kg/d group (0 4?0 7) and Losartan 10 mg/kg/d group (0 7?1 1) were both more decreased than in normal saline group(3 5?0 6) ( P

Objective: Recent studies have shown that cell implantation can replace infarcted myocardium to improve cardiac performance. The present study was designed to investigate the effects of autologous bone marrow mononuclear cell (BM-MNC) implantation into myocardium bordering the infarction with or without induced by 5-azacytidine on cardiac function after acute myocardial infarction (AMI) in rabbits. Methods: AMI was replicated by ligating the left anterior descending coronary artery. Rabbits were randomly divided into three groups: (1) BM -MNC induced by 5-azacytidine implantation (n=7), (2) BM-MNC implantation alo ne (n=7), and (3) AMI control (n=7). In addition, sham-operated (n=5) rabbit s were randomly selected to serve as non-infarction control. Animals for cell im p lantation were received intramyocardial injection of autologous BM-MNC in myoca rdium bordering the infarction, and echocardiography and hemodynamic studies wer e performed to evaluate cardiac function following 28 days of implantation. Results: Compared with the sham-operated group, the left ventricle (LV) end diastolic pressure (LVEDP) was significantly increased (P0.05). Conclusion: BM-MNC induced by 5-azacytidine implantation into myocardium bordering the infarction can significantly improve impaired cardiac function associated with LV remodeling after AMI, however such improvement is not further promoted compared with that in BM-MNC implantation group alone.

Objective To investigate the changes of apoptosis and expression of related apoptosis regulatory factors in neointima after canine coronary angioplasty Methods Stents were implanted in the left circumflex coronary artery in 15 canines Arteries were harvested at 1, 4, and 12 weeks after stenting Uninjured arteries were used as controls Apoptosis was demonstrated by the terminal uridine nick end labeling (TUNEL) method and transmission electron microscopy Proliferating cells were identified by immunostaining for proliferating cell nuclear antigen (PCNA) Expressions of Bcl xl proteins were detected by immunohistochemical method and Western blot Results Stents implantment induced intimal hyperplasia Apoptosis was not detected in control vessels Apoptotic cells and PCNA positive cells were identified at 1, 4, and 12 weeks with a peak at 1 week Profiles of apoptosis and cell proliferation after stenting were accordant in neointima, but cell proliferation rates were higher than cell apoptosis rates at all time points Expressions of Bcl-xl proteins were detected at 1 week, peaked at 4 weeks, and lasted till 12 weeks after stenting Conclusion Apoptosis may be an important determinant of in stent restenosis Bcl xl appears to play a critical role in regulating cell apoptosis

Objective To observe the frequency of interleukin-6(IL-6) gene -572C/G polymorphism and its relationship with myocardial infarction(MI) and serum lipids in Chinese Hans. Methods IL-6/gene-572C/G polymorphism was genotyped in 232 MI patients and 260 healthy adults by PCR-RFLP method. Results There were IL-6/gene-572 CC、CG and GG genotype. -572GG genotype and G allele were more frequent in patients than those in controls(P

Objective To investigate the value of treadmill exercise test and dipyridamole electrocardiography stress test (DP T) in diagnosis of coronary heart diseases (CHD), with an attemp of developing a safe, effective and simple diagnostic method for patients intolerable to the exercise. Methods Fifty two male patients aged from 41 to 75 years, averaged 58.44?8.79 years and with suspected or confirmed CHD were recruited to perform the treadmill exercise test, DP T and coronary angiography, respectively, within one month. Results The sensitivity and specificity of the treadmill exercise test for diagnosing CHD were 100% and 78.95%, respectively, while those of DP T for diagnosing CHD were 79.31% and 65.22%, respectively.As corresponded to the number of sites of coronary artery lesions,the numbers of cases with positive results revealed were 0, 2, 10 and 17 by the treadmill exercise tests and 0, 6, 11 and 15 by DP T, respectively.Based on the criteria of DP T, the sensitivity and specificity symptom, the changes in electrocardiography (ECG) and the combination of the two, for diagnosing CHD were 72.41%, 65.22%; 65.52%, 82.61%;and 79.31%, 65.22%, respectively. Conclusion The sensitivity and specificity of the treadmill exercise test and the DP T in the diagnosis of CHD were similar. More positive cases were revealed in above mentioned tests as the sites and degree of coronary artery lesion increased. DP T was particularly suitable for helping diagnose CHD in patients intolerable to exercise.

[ABSTRACT]AIM:ToevaluatetheeffectsofantisenseTGF-β1oligodeoxynucleotide(ASTGF-β1)ontheex-pression of TGF-β1 , deposition of extracellular matrix ( ECM) and the neointima formation in the arteries after balloon inju-ry.METHODS:The unmodified and phosphorothioate-modified AS TGF-β1 which containing 15 bases and surrounding the initiation codon region (ATG) of rat TGF-β1 complementary DNA (cDNA) were designed.At the same time, sense TGF-β1 oligodeoxynucleotide ( S TGF-β1 ) with the base sequence complement to AS TGF-β1 was synthesized as a control . The oligodeoxynucleotides were introduced into in vivo and in vitro experiments , respectively .RESULTS:The AS TGF-β1 significantly inhibited the protein expression of TGF-β1 in a concentration-dependent manner , and S TGF-β1 did not have the same effect.Furthermore, no effect of the AS TGF-β1 on the mRNA expression of TGF-β1 in injured VSMCs was ob-served.Moreover, for the injured VSMCs, AS TGF-β1 significantly and concentration-dependently inhibited the basal DNA synthesis.Both AS TGF-β1 and S TGF-β1 did not exhibit dose-dependent effects on DNA synthesis in uninjured VSMCs . Fibronectin ( FN) mRNA expression in injured VSMCs was significantly decreased by AS TGF-β1 in a concentration (0.01~1 μmol/L)-dependent manner .AS TGF-β1 significantly increased the mRNA expression of contractile marker SM 22α, and decreased the mRNA expression of synthetic markers osteopontin and matrix Gla , especially at the concentration of 0.01μmol/L and 0.1 μmol/L.After treatment with AS TGF-β1 (90 μg· kg-1 · d-1 ) for 28 d, the neointima formation was significantly inhibited , and the area ratio of intima/media was markedly decreased by 68% compared with untreated group , but S TGF-β1 had no effect on neointimal formation .CONCLUSION:The AS TGF-β1 specifically inhibits the pro-tein expression of TGF-β1 in the VSMCs derived from injured arteries .Moreover , it significantly inhibits DNA synthesis and cell proliferation, and decreases the expression of FN .Therefore, AS TGF-β1 dramatically attenuates neointima formation after balloon njury .The effects of AS TGF-β1 on the injured VSMCs may be associated with its reverse effects on the altera-tion of VSMC phenotype after balloon injury .