Effect of Losartan on the Cardiac and Renal Function in Patients With Chronic Heart Failure

Objectives To explore the effect of losartan on cardiac and renal function in patients with chronic heart failure (CHF). Methods Sixty-five patients with CHF were divided into two groups using a randomized, control and single blind method: losartan group (n=30) and convention group (n=35), with a treatment course of 8 weeks for both groups. The concentrations of cystatin C (cys C) in serum, microamount albumin (MA) in urine were measured by immunoturbidimetry. The concentration of aquaporin-2(AQP-2)was determined by enzyme-linked-immunosorbent assay (ELISA) and the heart contractile function was measured by echocardiography before and after treatment respectively. Results Comparing with routine treatment group, left ventricular end-diastolic dimension (LVEDd) decreased significantly, while left ventricular ejection fraction(LVEF)and left ventricular fractional shortening (LVFS) increased significantly in losartan group. The levels of cys C in serum and MA, AQP-2 in urine were significantly lower in losartan group than in routine treatment group. Conclusion Losartan can improve cardiac and renal function in patients with CHF.     

Relationship Between Serum Leptin Concentration and Lipids ＆ Body Mass Index in Patients With Chronic Congestive Heart Failure

Objectives To investigate the relationship of serum leptin concentration with the lipids and body mass index （BMI） in patients with chronic congestive heart failure（CHF）. Methods The serum concentration of leptin in 39 patients with CHF （14 in cardiac function class Ⅱ , 21 in class Ⅲ, 4 in classⅣ , NYHA） and in 46 patients with cardiac function class Ⅰ （NYHA） were assessed by radioimmunoassay. Results The serum concentration of leptin were 9.018±4.519 μg/l in CHF group （cardiac function class Ⅱ 11.492±5.649 μg/l, class Ⅲ 7.763±3.321 μg/l, class Ⅳ 6.100±2.657 μg/l）; 11.674± 6.911 μg/l in class Ⅰ group. The serum concentrations of leptin were significantly lower in CHF group, as compared with class Ⅰ group （P〈 0.05）. Moreover, the decrease of serum leptin concentration was significantly correlated with the decreased serum concentrations of total cholesterol, triglyceride, body mass index and left ventricular ejection fraction in CHF group, respectively （P 〈 0.05）. Conclusions The significance of the decrease in serum leptin in CHF patients needs further study.     

Protective effect of ascorbic acid in experimental gastric cancer：reduction of oxidative stress

AIM: Oxidative stress participates in the cell carcinogenesis by inducing DNA mutations. Our aim was to assess whether ascorbic acid, an antioxidant, could have a role in preventing ROS (Reactive Oxygen Species) generation in experimental gastric carcinoma in a rat model.METHODS: Experimental gastric cancer was induced in twelve Wistar male rats (weighting 250-350 g) by profound duodeno-gastric reflux throught split gastrojenunostomy. The rats were allocated to the following groups: Group Ⅰ (n=6)was the control; Group Ⅱ (n=6) which was mantained with daily intake of tape water with Vitamin C (30 mg/Kg). After 6 or 12 months, samples of gastric tumor or non tumor mucosa were taken from the anastomosis of both groups.Oxidative stress was measured by superoxide quantification through lucigenin-amplified chemiluminescence base and by staining with Nitrobluetetrazolium. The histopathologic confirmation of adenocarcinoma was made by eosinhemathoxilin method.RESULTS: The intestinal type of gastric adenocarcinoma was microscopically identified in all animals of group Ⅰwhereas only 3 rats of group Ⅱ showed an adenocarcinoma without macroscopic evidence of them. The cancers were located in the anastomosis in all cases. Basal luminescence from tumor gastric tissue generated 38.4±6.8 count per minute/mg/x106 (mean±SD) and 14.9±4.0 count per minute/mg/×106, respectively, in group Ⅰ and Ⅱ animals (P＜0.05). The Nitrobluetetrazolium method showed intense staining in tumor tissues but not in non neoplasic mucosa.CONCLUSION: Experimental gastric tumors seem to produce more reactive oxygen species than non neoplasic gastric tissue. The reduction of oxidative stress and gastric tumor incidence in rats were induced by the intake of ascorbic acid. Therefore, it may have a role in the prevention of gastric carcinoma.     

Thyroxine treatment for elderly patients with heart failure and sick euthyroid syndrome

Objectives To evaluate the effect of thyroid hormone therapy with low dose of thyroxin on cardiac function in elderly patients with heart failure and sick euthyroid syndrome.Methods Forty-seven patients(33 males and 14 females,mean age 85.9±4.6 years, ranging from 80 to 99 years)with chronic heart failure(NYHAⅡ-Ⅳ)and low triiodothyronine(T_3)state were randomly allocated to the treatment group or control group.The treatment group patients received oral administration of levothyroxine sodium(Euthyrox)25-50 mg/d in addition to conventional therapy of heart failure,whereas patients in control group were given conventional therapy only.Serum level of total T_3(TT_3),free T_3(FT_3),total thyroxine(TT_4),free thyroxine(FT_4),and thyroid-stimulating hormone(TSH)were determined.For both groups,left ventricular ejection fraction(LVEF)and stroke volume(SV)were assessed by two-dimensional echocardiography before and at 8 weeks after treatment.The changes of these parameters after the treatment were evaluated by adjusting heart rate in the two groups.Results The reduced serum T_3 level in the treatment group was corrected after thyroid hormone therapy, and these patients had a significant improvement in cardiac function after treatment.By contrast,in the control group only changes of serum TT_3 and TT_4 levels and SV and LVEF after treatment were statistically significant.The heart rate-adjusted mean SV and LVEF in both groups were also increased,which was significantly greater in the treatment group than in the control group.Conclusion In the elderly patients with heart failure and sick euthyroid syndrome,addition of thyroxine at a low dosage to the conventional treatment could effectively improve the low T_3 state and cardiac function independent of changes of heart rate.     

Effect of ischemic preconditioning on P-selectin expression in hepatocytes of rats with cirrhotic ischemia-reperfusion injury

AIM: To investigate the effects and mechanisms of ischemic preconditioning (IPC) on the ischemia/reperfusion (I/R) injury of liver cirrhosis in rats and the effect of IPC on P-selectin expression in hepatocytes.METHODS: Forty male SD rats with liver cirrhosis were randomly divided into sham operation group (SO group),ischemia/reperfusion group (I/R group), ischemic preconditioning group (IPC group), L-Arginine preconditioning group (APC group), L-NAME preconditioning group (NPC group), eight rats in each group. Hepatocellular viability was assessed by hepatic adenine nucleotide level and energy charge (EC) determined by HPLC, ALT, AST and LDH in serum measured by auto- biochemical analyzer and bile output.The expression of P-selectin in the liver tissue was analyzed by immunohistochemical technique. Leukocyte count in ischemic hepatic lobe was calculated.RESULTS: At 120 min after reperfusion, the level of ATP and EC in IPC and APC groups was higher than that in I/R group significantly. The increases in AST, ALT and LDH were prevented in IPC and APC groups. The livers produced more bile in IPC group than in I/R group during 120 min after reperfusion (0.101±0.027 versus 0.066±0.027 ml/g liver,P=0.002). There was a significant difference between APC and I/R groups, (P=0.001). The leukocyte count in liver tissues significantly increased in I/R group as compared with SO group (P＜0.05). The increase in the leukocyte count was prevented in IPC group. Administration of L-arginine resulted in the same effects as in IPC group. However,inhibition of NO synthesis (NPC group) held back the beneficial effects of preconditioning. Significant promotion of P-selectin expression in hepatocytes in the I/R group was observed compared with the SO group (P＜0.01). IPC or L-arginine attenuated P-selectin expression remarkably (P＜0.01). However, inhibition of NO synthesis enhanced Pselectin expression (P＜0.01). The degree of P-selectin expression was positively correlated with the leukocyte counts infiltrating in liver (r=0.602, P=0.000).CONCLUSION: IPC can attenuate the damage induced by I/R in cirrhotic liver and increase the ischemic tolerance of the rats with liver cirrhosis. IPC can abolish I/R induced leukocyte adhesion and infiltration by preventing postischemic P-selectin expression in the rats with liver cirrhosis via a NO-initiated pathway.     

胰岛素样生长因子对心力衰竭大鼠心肌细胞黏附分子1表达的影响

Objective To investigate the effect of insulin-like growth factor-1 (IGF-1) on intercellular adhesion molecule-1 (ICAM-1) expression in rat model with congestive heart failure (CHF). Methods The model of CHF in male Sprague-Dawley rat was established using subcutaneous injection of isoproterenol. The rats were randomized into model group (n = 10),angiotensin converting enzyme inhibitors (ACEI) group ( n=10) and IGF- 1 group ( n = 10). The rats injected with saline were used as normal controls (n=10). The haemodynamic parameters of rats in each group were detected. The concentration of plasma angiotensin Ⅱ (Ang Ⅱ ) and expression of ICAM-1 in rat myocardium were determined by radioimmunoassay and immunohistochemistry,respectively. Results Compared with model group, ACEI and IGF-1 could rescue the diversities of hemodynamic parameters. In addition, ACEI and IGF-1 could also significantly down-regulated concentration of plasma Ang Ⅱ and inhibited ICAM-1 expression. Compared with ACEI, IGF-1 more significantly inhibited ICAM-I expression (0. 804 ± 0. 024 vs. 1. 254 ± 0. 059) and down-regulated concentration of plasma AngⅡ [(369.2±65.0) μg/L vs. (384.4±56.2) μg/L]. Conclusions IGF-1 can suppress ICAM-1 expression in rat model with CHF induced by isoproterenol. This effect may be related to inhibiting activation of RAS system.     

Effects of garlicin on apoptosis in rat model of colitis

AIM:To investigate the effects of garlicin on apoptosis and expression of bcl-2 and bax in lymphocytes in rat model of ulcerative colitis (UC). METHODS:Healthy adult Sprague-Dawley rats of both sexes, weighing 180±30 g, were employed in the present study. The rat model of UC was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enema. The experimental animals were randomly divided into garlicin treatment group (including high and low concentration), model control group, and normal control group. Rats in garlicin treatment group and model control group received intracolic garlicin daily at doses of 10.0 and 30.0 mg/kg and equal amount of saline respectively 24 h after colitis model was induced by alcohol and TNBS co-enema. Rats in normal control group received neither alcohol nor only TNBS but only saline enema in this study. On the 28~(th) d of the experiment, rats were executed, the expression of bd-2 and bax protein was determined immunohistochemically and the apoptotic cells were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method. At the same time, the rat colon mucosal damage index (CMDI) was calculated. RESULTS:In garlicin treatment group, the positive expression of bd-2 in lymphocytes decreased and the number of apoptotic cells was more than that in model control group, CMDI was lower than that in model control group. The positive expression of bax in lymphocytes had no significant difference. CONCLUSION:Garlicin can protect colonic mucosa against damage in rat model of UC induced by TNBS enema.     

Preventive effect of hydrotalcite on gastric mucosal injury in rats induced by taurocholate

AIM: To study the preventive effect of hydrotalcite on gastric mucosal injury in rat induced by taurocholate, and to investigate the relationship between the protective mechanism of hydrotalcite and the expression of trefoil factor family 2 (TFF2) mRNA and c-fos protein.METHODS: Forty five male Wistar rats were randomly divided into hydrotalcite group, ranitidine group and control group. Gastric mucosal injury was induced by introgastric acidified taurocholate. OD value of TFF2 mRNA expression in gastric mucous cells was determined by hybridization and computer image analysis system. OD value of c-fos protein expression in gastric mucous cells was measured by immunohistochemistry and computer image analysis system.RESULTS: The gross mucosal injury index in hydrotalcite group was significantly lower than that in ranitidine group and control group (8.60±2.20 vs 16.32±4.27, 29.53±5.39;P＜0.05, P＜0.01). The expression level of TFF2 mRNA in hydrotalcite group was markedly higher than that in ranitidine group and control group (0.56±0.09 vs 0.30±0.05, 0.28±0.03,P＜0.05). The OD value of c-fos protein in hydrotalcite group was higher than that in ranitidine group and control group (0.52±0.07 vs 0.31±0.04, 0.32±0.05, P＜0.05).CONCLUSION: Hydrotalcite can protect gastric mucosal injury in rats induced by taurocholate, which may be related to the increased expression of TFF2 and c-fos protein.     

Mast cell tryptase and carboxypeptidase A expression in body fluid and gastrointestinal tract associated with drug-related fatal anaphylaxis

AIM: To investigate the expression of mast cell tryptase and carboxypeptidase A in drug-related fatal anaphylaxis.METHODS: The expression of mast cell tryptase and carboxypeptidase A in 15 autopsy cases of drugrelated fatal anaphylaxis and 20 normal autopsy cases were detected. First, the expression of mast cell tryptase was determined in stomach, jejunum, lung, heart, and larynx by immunofluorescence. Different tissues were removed and fixed in paraformaldehyde solution, then paraffin sections were prepared for immunofluorescence. Using specific mast cell tryptase and carboxypeptidase A antibodies, the expression of tryptase and carboxypeptidase A in gastroenterology tract and other tissues were observed using fluorescent microscopy. The postmortem serum and pericardial fluid were collected from drug-related fatal anaphylaxis and normal autopsy cases. The level of mast cell tryptase and carboxypeptidase A in postmortem serum and pericardial fluid were measured using fluor enzyme linked immunosorbent assay(FEIA) and enzyme linked immunosorbent assay(ELISA) assay. The expression of mast cell tryptase and carboxypeptidase A was analyzed in drug-related fatal anaphylaxis cases and compared to normal autopsy cases.RESULTS: The expression of carboxypeptidase A was less in the gastroenterology tract and other tissues from anaphylaxis-related death cadavers than normal controls. Immunofluorescence revealed that tryptase expression was significantly increased in multiple organs, especially the gastrointestinal tract, from anaphylaxis-related death cadavers compared to normal autopsy cases(46.67 ± 11.11 vs 4.88 ± 1.56 in stomach, 48.89 ± 11.02 vs 5.21 ± 1.34 in jejunum, 33.72 ± 5.76 vs 1.30 ± 1.02 in lung, 40.08 ± 7.56 vs 1.67 ± 1.03 in larynx, 7.11 ± 5.67 vs 1.10 ± 0.77 in heart, P 0.05). Tryptase levels, as measured with FEIA, were significantly increased in both sera(43.50 ± 0.48 μg/L vs 5.40 ± 0.36 μg/L, P 0.05) and pericardial fluid(28.64 ± 0.32 μg/L vs 4.60 ± 0.48 μg/L, P 0.05) from the anaphylaxis group in comparison with the control group. As measured by ELISA, the concentration of carboxypeptidase A was also increased more than 2-fold in the anaphylaxis group compared to control(8.99 ± 3.91 ng/m L vs 3.25 ± 2.30 ng/m L in serum, 4.34 ± 2.41 ng/m L vs 1.43 ± 0.58 ng/m L in pericardial fluid, P 0.05).CONCLUSION: Detection of both mast cell tryptase and carboxypeptidase A could improve the forensic identification of drug-related fatal anaphylaxis.     

携带人B型利钠肽基因重组腺病毒对慢性心力衰竭大鼠心功能的影响

目的 观察外源基因人B型利钠肽对慢性心力衰竭(心衰)大鼠心功能的影响.方法 30只入选心衰大鼠,随机分为携带人B型利钠肽基因重组腺病毒组(Ad-hBNP组)、重组空白腺病毒组(Ad-Track组)、生理盐水组(NS组),另设不予任何治疗的假手术组作为对照;分别经腹腔注射予以相应治疗,每周1次,共4周.4周后实验动物行超声心动图、血流动力学检测,酶联免疫吸附试验检测血清外源基因人B型利钠肽水平,全心质量指数检测.结果 间断Ad-hBNP治疗后,Ad-hBNP组心衰大鼠室间隔厚度、左室后壁厚度、左室舒张末径、左室收缩末径[(2.34±0.29)mm、(2.28±0.18)mm、(6.50±0.42)mm、(3.54±0.59)mm]显著低于Ad-Track组[(2.71±0.35)mm、(3.02±0.85)mm、(7.71±0.83)mm、(4.72±0.80)mm,均为P＜0.05]和NS组[(2.78±0.23)mm、(2.83±0.53)mm、(7.34±0.97)mm、(4.55±0.77)mm,均为P＜0.05],而左室射血分数、左室短轴缩短率[(79.27±7.01)%、(43.38±6.73)%]显著高于Ad-Track组[(70.85±4.81)%、(35.72±3.68)%,均为P＜0.01]和NS组[(69.67±6.90)%、(34.91±5.10)%,均为P＜0.01].Ad-hBNP组与Ad-Track组和NS组比较:心率显著降低,左室收缩压显著升高[为(131.79±15.76)mm Hg(1 mm Hg=0.133 kPa)、(112.99±32.35)mm Hg、(117.13±15.26)mm Hg],左室内压最大上升速率显著升高[分别为(5037.20±430.41)mm Hg/s、(4217.40±1354.15)mm Hg/s、(4310.50±1293.97)mm Hg/s;P＜0.05];左室内压最大下降速率显著升高[分别为(-4382.00±1304.79)mm Hg/s、(-3725.00±791.34)mm Hg/s、(-3890.00±1043.73)mm Hg/s,均为P＜0.05];左室舒张末压降低[分别为(-4.24±4.00)mm Hg、(21.99±6.80)mm Hg、(18.00±12.25)mm Hg,均为P＜0.01];心脏质量及全心质量指数均降低.结论 间断给予Ad-hBNP能够有效地改善心衰大鼠心脏结构和功能.

Abstract：

Objective To evaluate the therapeutic effect of hBNP on rats with chronic heart failure (CHF). Methods Thirty CHF rats defined by echocardiography at 12 weeks post abdominal aortic constriction were randomly divided into Ad-hBNP group (2. 5 × 1010 VP/ml NS Ad-hBNP 1 ml/week ×4,n = 14), Ad-Track group ( n = 8 ), placebo group ( NS, n = 8 ), 10 sham-operated rats served as control group. After 4 weeks treatment, cardiac function was evaluated by echocardiography and hemodynamic measurements. Heart weight (HW) and HW/body weight (BW) ratio were determined. Results IVS,LVPW, LVEDD and LVESD were significantly reduced in the Ad-hBNP group [(2. 34 ±0. 29)mm, (2. 28 ± 0. 18)mm, (6. 50 ±0. 42)mm, (3.54 ±0. 59) mm] than those in the Ad-Track group[(2. 71 ±0. 35) mm,(3.02 ±0.85)mm, (7.71 ±0.83)mm, (4.72 ±0.80)mm] and in the NS group [(2.78 ±0.23)mm,(2. 83 ± 0. 53 ) mm, (7. 34 ± 0. 97 ) mm, (4. 55 ± 0. 77 ) mm, all P ＜ 0. 05]. The LVEF and LVFS of the Ad-hBNP group [(79. 27 ±7.01 )%, (43.38 ±6. 73)%] were significantly higher than in the Ad-Track group[(70.85±4.81)%, (35.72 ±3.68)%] and in the NS group[(69.67 ±6.90)%, (34.91 ±5.10)%, all P ＜0. 01]. HR[(417.48 ±32. 57) beats/min, (446. 85 ±61.49) beats/min, P ＜0. 05;(440. 83 ±32. 18) beats/min , P ＜0. 05], LVEDP[( - 4. 24 ±4. 00) mm Hg( 1 mm Hg =0. 133 kPa);(21.99 ±6. 80) mm Hg, P ＜0. 01; ( 18.00 ± 12. 25)mm Hg, P＜0. 01] were significantly decreased and while LVSP[(131.79 ±15.76) mm Hg; (112.99 ±32.35) mm Hg, P＜0.05; (117.13 ±15.26)mmHg], +dP/dtmax[(5037.20 ±430.41) mm Hg/s; (4217.40 ± 1354. 15)mm Hg/s, P ＜0.05;(4310. 50 ± 1293.97 ) mm Hg/s, P ＜ 0. 05] and - dP/dtmax [( - 4382. 00 ± 1304. 79 ) mm Hg/s;(-3725.00±791.34) mm Hg/s, P ＜ 0.05; ( - 3890.00 ± 1043.73) mm Hg/s, P ＜ 0.05] were significantly increased in Ad-hBNP group than in Ad-Track group and NS group ( all P ＜ 0. 05 ). HW and HW/BW were also decreased in Ad-hBNP group than in the Ad-Track group and the NS group. Conclusion Exogenous hBNP improved the cardiac function and attenuated remodeling in CHF rats.     

缬沙坦对心力衰竭家兔钙调蛋白依赖性蛋白激酶Ⅱ的影响

目的 探讨家兔慢性心力衰竭(心衰)时心肌钙调蛋白依赖性蛋白激酶Ⅱ(CaMKⅡ)蛋白表达及活性的改变及血管紧张素Ⅱ受体拮抗剂缬沙坦长期干预的意义.方法 27只家兔随机分为3组,假手术组、心衰组和缬沙坦组各9只,通过超容量负荷联合压力负荷建立家兔心衰模型,于术后7周观察左心室结构、血液动力学的变化及CaMK Ⅱ的表达和活性的改变.结果 与假手术组比较,心衰组左室重量指数(LVMI)、左窒舒张末压显著升高(P＜0.05),左室短轴缩短率及左室射血分数明显降低(P＜0.05);与心衰组比较,缬沙坦组左室重量指数、左室舒张未压显著降低(P＜0.05),左室短轴缩短率及左室射血分数明显升高(P＜0.05);心衰组CaMK Ⅱ蛋白表达及活性显著高于假手术组(P＜0.05);缬沙坦组CaMKⅡ蛋白表达及活性显著低于心衰组(P＜0.05).结论 缬沙坦长期干预心衰,能够改善心脏舒缩功能,可能与其降低CaMK Ⅱ蛋白表达及活性有关.     

改良心导管测定大鼠肺血管阻力的方法

目的 建立一种简单、可重复性强的测定正常及肺动脉高压大鼠肺血管阻力的方法.方法 雄性Sprague-Dawley( 180 ～ 200 g)大鼠45只,随机分为3组:正常对照组、低剂量野百合碱组(50 mg/kg)和高剂量野百合碱组(60 mg/kg).给予大鼠颈背部皮下一次性注射野百合碱建立肺动脉高压大鼠模型.大鼠肺动脉压力采用自制改良的末端呈圆弧形的PE- 50导管行右心导管法测定.心输出量利用热稀释法原理检测.肺血管阻力由平均肺动脉压力除心输出量得出.结果 三组大鼠肺动脉压力、心输出量及肺血管阻力的检测总成功率均分别为98％、100％和96％,组间差异无统计学意义.注射野百合碱21 d后,低、高剂量野百合碱组大鼠的平均肺动脉压均显著高于对照组[(43.1±0.8)mm Hg(1 mm Hg=0.133 kPa)、(54.8±2.2) mm Hg比(17.4±1.0) mm Hg,P均＜0.001],且高剂量组明显高于低剂量组(P＜0.001).低、高剂量野百合碱组大鼠心输出量均明显低于对照组[(77.5±6.9) ml/min、(71.0+6.7)ml/min比(126.8±3.9) ml/min,P均＜0.001],低、高剂量组间差异无统计学意义.低、高剂量野百合碱组大鼠肺血管阻力均显著高于对照组[(0.56±0.06) mm Hg·min-1·ml-1、(0.76±0.08)mm Hg·min-1·ml-1比(0.13±0.01)mm Hg- min-1·ml-1,P均＜0.001],且高剂量组明显高于低剂量组(P=0.01).结论 采用此方法检测大鼠肺血管阻力准确、可靠、操作性强,具有推广价值.     

过表达肌浆网钙ATP酶治疗实验性慢性缺血性心力衰竭

目的 研究肌浆网钙ATP酶2a(SERCA2a)基因过表达对慢性缺血性心力衰竭(心衰)心功能及心肌内质网应激(ERS)相关凋亡的影响.方法采用ameroid环束扎小型猪前降支制备慢性缺血性心衰模型.开胸心肌内注射重组腺相关病毒以过表达SERCA2a或对照报告基因绿色荧光蛋白.60 d后检测血流动力学、SERCA2a的表达和活性、心肌凋亡及ERS标志蛋白-分子伴侣GRp78、凋亡蛋白caspase-12的表达.结果基因转导后60 d,与心衰对照及报告基因组相比,转基因组SERCA2a蛋白表达和活性显著增高,心功能参数改善,心肌凋亡指数降低,伴GRP78和活化caspase12表达下降.结论过表达SERCA2a可改善慢性缺血性心衰的心脏功能,其机制可能涉及减轻ERS相关的心肌细胞凋亡.

Abstract：

Objective Chronic myocardial ischemia (CMI) has become the most importat cause of heart failure (HF) all over the world. The aim of the current study was to investigate the effects of Sarcoendoplasmic reticulum calcium ATPaee 2a (SERCA2a) gene transfer on cardiac function and endoplasmic reticulum stress (ERS) associated myocardial apoptosis in a minipig HF animal model induced by CMI. Methods HF was induced in minipigs by implantation of ameroid constrictor in the initial segment of left anterior descending (LAD) branch of coronary artery. After confirmation of myocardial perfusion defects and cardiac function impairment by myocardial perfusion imaging and echocardiography, animals were divided into 4 groups (n =4 each): HF group, HF + enhanced green fluorescent protein (EGFP) group,HF + SERCA2a group, and shamed animals as control group. A total amount of 1×1012 v.g. Of rAAV1EGFP or rAAV1-SERCA2a were injected intramyocardially to each animal of HF + EGFP and HF +SERCA2a groups. Sixty days after gene transfer, protein level and activity of SERCA2a were examined,cardiac functions and changes of serum inflammatory and neuro-hormonal factors were determined. Apoptotic index of the ischemic myocardium, protein levels of ER stress marker glucose regulated protein 78 ( GRP 78) and ER stress specific apoptotic marker caspase-12 were also assayed. Results At the study end,echocardiographic and hemodynamic measurements indicated a significant improvement of both cardiac systolic and diastolic function in HF + SERCA2a group compared with HF/HF + EGFP groups [LVEF (60.2±8.6)%vs (44.2±7.1)% and (46.8±6.7)%, Ev/Ay 1.28±0.24 vs 0.77 ±0.17 and 0.80±0.21, +dp/dtmax(2713.9 ±434.0) mm Hg/s ( 1 mm Hg =0.133 kPa) vs (1892.3 ±434.2) mm Hg/s and (1931.2±397.4)mm Hg/s, -dp/dtmax (1422.1±334.4) mm Hg/s vs (848.3±308.3) mm Hg/s and (849.5±278.3)mm Hg/s, P＜0.05], along with increase in both SERCA2a protein level (1.13±0.26 vs 0.73 ±0.17 and 0.64±0.18, P＜0.05) and activity [(16.2±5.5) IU/ml vs (7.9±3.1) IU/ml and (7.5 ±2.8)IU/ml, P ＜0.05] compared with HF/HF + EGFP groups. Serum concentrations of inflammatory factor tumor necrotic factor α [(382.3±114.4) ng/L vs (732.3±201.4) ng/L and (689.8±192 5) ng/L, P＜0. 05], neural-hormonal factors brain natriuretic peptide [(142.6±45.3) ng/L vs (422.3±113.6) ng/L and(393.7 ±103.3)ng/L, P＜0.01], endothelin-1 [(111.4 ±37.5)ng/L vs (193.5 ±54.3)ng/L and (201.0±72.1)ng/L,P＜0.05] and angiotensin Ⅱ[(189.7±65.2)μg/L vs (538.3 ± 135.2) μg/L and ( 525.5±144.1)μg/L, P＜0.01] were also significantly decreased in HF + SERCA2a group compared with HF/HF + EGFP groups. The apoptotic index [(12.71±4.11)% vs(23.22±7.23) % and (24.31±6.38)%, P＜0.05], protein levels of GRP78 (1.27±0.33 vs 3.23±1.14 and 4.18±1.13, P＜0.05)and protein level ratios of cleaved caspase-12 to total caspase-12[(4.62±1.93)% vs (9.71±2.70)% and (10.14±2.81)%, P＜0.05] were also significantly reduced in the ischemic myocardium of HF+SERCA2a group compared with the HF/HF + EGFP groups. Conclusion Overexpression of SERCA2a significantly improved cardiac systolic and diastolic function in this HF model partly through attenuation of ER stress related myocardial apoptosis, suggesting its therapeutic potential for CM1 related heart failure.     

异丙肾上腺素诱导大鼠急性心肌缺血损伤心电图观察指标的研究

目的 探讨以心电图为观察指标,评价异丙肾上腺素(ISO)经尾静脉给药诱导大鼠急性缺血性心肌损伤模型的可靠性,为实验性心肌损伤模型复制和应用提供参考.方法 雄性Wistar大鼠70只,按体质量随机分为5、10、20、40、80、160、320、640、1280、2560μg/kg 10个剂量组,每组7只.采用尾静脉注射方式,按体质量给予各组大鼠相应剂量的用生理盐水稀释后的ISO;应用心电图标准肢体Ⅰ、Ⅱ、Ⅲ导联,分别记录大鼠用药前及用药即刻、1、24、72 h的心电图;观察和测量各组大鼠心率、Ⅱ导联T波振幅、Q-T间期的变化情况.结果 大鼠心率、心电图T波振幅及Q-T间期在不同观察时间均明显不同(F值分别为15.03、11.28、13.64,P均＜0.01),不同ISO剂量间的三者组间比较差异均无统计学意义(F值分别为1.45、1.17、1.09,P＞0.05);观察时间与ISO剂量之间无交互作用(F值分别为0.79、0.82、0.59,P均＞0.05).注射ISO后即刻测得各组大鼠心率均较用药前显著增快(P均＜0.01),其中以320、640μg/kg组[(550±47)、(521±43)次/min]增快最为明显;各组T波较给药前显著下降(P均＜0.01),20μg/kg以上剂量组下降尤为明显,呈现倒置;各组大鼠心电图Q-T间期较给药前均显著缩短(P均＜0.01),且以320、640、1280、2560μg/kg组缩短更为明显,分别为(0.070±0.006)、(0.072±0.005)、(0.068±0.005)ms.注射ISO后1 h测量发现,各组大鼠心率均有所下降,除320、640μg/kg剂量组心率[(518±43)、(487±36)次/min]仍高于用药前[(450±40)、(448±51)次/min,P均＜0.05],其余剂量组大鼠心率与用药前比较已无明显差异(P均＞0.05);各组大鼠心电图T波均较用药即刻显著回升(P均＜0.05),40μg/kg以上剂量组回升幅度较大,但与用药前相比仍有差异(P＜0.05),而40μg/kg以下剂量组大鼠T波已回复至用药前水平;各组Q-T间期均有不同程度的恢复,1280和2560 μg/kg组[(0.080±0.004)、(0.076±0.011)ms]仍短于用药前[(0.086±0.007)、(0.085±0.006)ms,P均＜0.05],其余各组与用药前比较,差异无统计学意义(P均＞0.05).注射ISO后24 h,1280和2560μg/kg组大鼠心率[(389±31)、(398±23)次/min]较用药前[(427±43)、(438±26)次/min]显著下降(P均＜0.05),其余剂量组大鼠心率进一步恢复至用药前水平.注射ISO后72 h,所有剂量组大鼠心率、T波振幅及Q-T间期均恢复至用药前水平(P均＞0.05).结论 大鼠心电图无明显ST段改变,ISO对于缩短Q-T间期的作用确切;T波振幅、Q-T间期可以作为评价动物模型的可靠心电图指标.

Abstract：

Objective To explore the reliability of relevant electrocardiogram(ECG) indexes in evaluating isoprenaline(ISO)-induced rat acute ischemic myocardial injury and provide reference for future scientific applications of these models. Methods Seventy male Wistar rats were randomly equally assigned to ten groups according to their body weight: 5,10,20,40,80,160,320,640, 1280 and 2560 μg/kg dose groups. All rats were tail intravenously given corresponding doses of saline diluted isoprenaline according to their body weight. Standard limb Ⅰ , Ⅱ, Ⅲ-lead ECG of all rats were recorded before, immediately after and 1,24,and 72 hour after injection, respectively.Changes of heart rate, T-wave amplitude of Ⅱ -lead and Q-T interval were measured. Results Significant differences were found in heart rates, T-wave amplitudes and Q-T intervals at different time points(F = 15.03,11.28,13.64, all P ＜ 0.01 ), while differences among the ten ISO-dose groups were statistically insignificant (F= 1.45, 1.17,1.09, all P ＞ 0.05). No interaction between observation time and ISO dose was observed on heart rates, T-wave amplitudes and Q-T intervals(F= 0.79,0.82,0.59, all P ＞ 0.05). Immediately after injection of ISO, the heart rates were significantly increased compared with that of pre-injection in all groups(all P ＜ 0.05), of which 320 and 640μg/kg dose groups increased most significantly [(550 ± 47), (521 ± 43)times/min]. T-waves decreased significantly compared with that of pre-injection (all P ＜ 0.01 ), and 20 μg/kg dose and above groups decreased particularly evident, and partly inverted. Q-T intervals of rats in each group were significantly shorter than that of pre-injection(all P ＜ 0.01 ), and 320, 640, 1280 μg/kg groups shortened more pronounced[(0.070 ± 0.006),(0.072 ± 0.005), (0.068 ± 0.005)ms]. One hour after injection, the heart rate of rats in each group decreased,except 320 and 640 μg/kg dose groups[(518 ± 43), (487 ± 36)times/min], which were still higher than that of pre-treatment[(450 ± 40), (448 ± 51 )times/min, all P ＜ 0.05], the rest groups no longer had significant differences (all P ＞ 0.05). ECG T-wave in each group was significantly recovered compared with that of instantly medication (all P＜0.05), and 40 μg/kg dose and above groups recovered more than a big margin, but there were still differences compared with that of pre-treatment (P ＜0.05), while T-waves of 40 μg/kg dose and below groups had returned to the level of pre-treatment. Q-T interval in each group had varying degrees of recovery, except 1280 and 2560 μg/kg dose groups[(0.080 ± 0.004), (0.076 ± 0.011 )ms]which were still less than that of pre-treatment[(0.086 ± 0.007),(0.085 ± 0.006)ms, all P ＜ 0.05], other groups had no significant difference compared with that of pre-treatment (all P ＞ 0.05). Twenty-four hours after injection of ISO, the heart rates of 1280 and 2560 μg/kg dose groups [(389 ± 31 ), (398 ± 23)times/min]decreased significantly compared with that of pre-treatment[(427 ± 43), (438 ±26)times/min, all P ＜ 0.05], while other groups had returned to the level of pre-treatment. Seventy-two hours after injection of ISO, the heart rates, T-wave amplitudes and Q-T intervals of all doses groups had returned to the level of pre-treatment (all P ＞ 0.05). Conclusions There has no significant ST segment in the electrocardiogram of rat.Isoprenaline has an exact effect on shortening Q-T interval. T-wave amplitude and Q-T interval can be used as reliable indexes of ECG for assessment of this animal model.     

缬沙坦联合氨氯地平或氢氯噻嗪对老年高血压患者血压变异性的影响

目的 比较缬沙坦联合氨氯地平或氢氯噻嗪对老年高血压患者血压变异性及一氧化氮、内皮素的影响.方法选取61例2、3级老年高血压患者,随机分为两组,分别给予缬沙坦+氨氯地平或缬沙坦+氢氯噻嗪行降压治疗,观察入选时、治疗第8周和第16周各种相关指示的变化.人选时检测血脂、空腹血糖、血尿酸,试验各个阶段监测24 h动态血压,检测血浆一氧化氮、内皮素水平.结果在患者入选时、治疗第8周和第16周三个时间点,缬沙坦+氨氯地平组和缬沙坦+氢氯噻嗪组24 h血压及白昼血压比较差异无统计学意义.治疗第16周,缬沙坦+氨氯地平组晨峰收缩压较缬沙坦+氢氯嚷嗪组明显降低[(22.6±8.8)mm Hg(1 mm Hg=0.133 kPa)比(26.3±13.7)mm Hg,P＜0.05];缬沙坦+氨氯地平组及缬沙坦+氢氯噻嗪组24 h收缩压变异性(SBPV)进行性降低[缬沙坦+氨氯地平组:(12.5±2.8)mm Hg比(10.2 ±2.2)mm Hg比(8.8±1.6)mm Hg,P＜0.01;缬沙坦±氢氯噻嗪组:(12.5±2.5)mmHg比(10.7±2.2)mm Hg比(9.6±2.0)mmHg,P＜0.01],缬沙坦+氨氯地平组及缬沙坦+氢氯噻嗪组白昼SBPV明显降低[缬沙坦+氨氯地平组:(12.2±3.0)mm Hg比(10.1±2.3)mm Hg比(8.4±1.9)mm Hg,P＜0.01;缬沙坦+氢氯噻嗪组:(11.8±2.7)mm Hg比(10.4±1.9)mm Hg比(9.6±2.2)mm Hg,P＜0.01],缬沙坦+氨氯地平组24 h舒张压变异性(DBPV)显著降低[(15.5±3.4)mm Hg比(13.0±3.5)mm Hg比(12.3±2.5)mm Hg,P＜0.01],缬沙坦+氢氯噻嗪组24 h DBPV无显著性变化;缬沙坦+氨氯地平组第16周白昼SBPV低于缬沙坦+氢氯噻嗪组[(8.4±1.9)mm Hg比(9.6 ±2.2)mm Hg,p＜0.05],缬沙坦+氨氯地平第8周、第16周的24 h DBPV、白昼DBPV低于缬沙坦+氢氯噻嗪组(P ＜0.01～0.05);缬沙坦+氨氯地平组一氧化氮进行性升高[(27.3±13.6)μmol/L比(47.2±16.3)μmol/L比(69.5±18.9)μmol/L,P＜0.01]、内皮素进行性降低[(45.3±8.0)ng/L比(37.4±3.9)ng/L比(34.2±4.4)ng/L,P＜0.01];缬沙坦+氢氯噻嗪组一氧化氮进行性升高[(33.5±13.9)μmol/L 比(49.7±21.9)μmol/L比(66.7 ±24.7)μmol/L,P＜0.01]、内皮素显著降低[(46.6±10.4)ng/L比(37.0±5.4)ng/L比(36.1±8.2)ng/L,P＜0.01].治疗第8周,缬沙坦+氨氯地平组收缩压变异性的降幅与一氧化氮的升幅有相关性(r =0.401,P=0.025).结论缬沙坦联合氨氯地平或氢氯噻嗪均能降低老年高血压患者血压变异性、改善血管内皮功能,缬沙坦联合氨氯地平可能更适合于老年高血压患者.     

骨髓间充质干细胞对大鼠梗死心肌胶原重构的双重调节作用

目的 探讨骨髓间充质干细胞(MSC)对梗死心肌胶原重构的调节作用。方法 采用结扎冠状动脉前降支的方法复制大鼠心肌梗死(MI)模型,随机分为假手术组（仅穿线不结扎冠状动脉,n=8）、MI+ PBS组（结扎冠状动脉+心肌注射PBS溶液,n=8）和MI+ MSC组（结扎冠状动脉+心肌注射MSC,n=8）。通过心脏超声检查、血液动力学检查和组织学染色方法分别检测左心室射血分数(LVEF)、短轴缩短率(FS)、左心室收缩末压力(LVSP)、左心室舒张末压力(LVEDP)、左心室压最大升降速率（±dp/dtmax）、心肌梗死面积和梗死扩张指数等指标,评价MSC对大鼠心功能及心室重构的影响。同时采用免疫组化、RT-PCR、Western blot等方法,测量胶原蛋白表达情况。结果 (1)MI大鼠心室重构和心脏功能指标的检测结果：MI+ MSC组大鼠心肌梗死面积显著小于MI+ PBS组[(38.27±2.70)％比(46.20±3.17)％,t=5.386,P＜0.001],FS显著高于MI+ PBS组[(29.98±4.50)％比(23.43 ±3.34)％,t=-3.305,P=0.005],LVSP显著高于MI+ PBS组[(113.63±10.81)mm Hg(1 mm Hg=0.133 kPa)比（99.25±16.76）mm Hg,P＜0.05],LVEDP显著低于MI+PBS组[(12.10±4.28) mm Hg比(20.08±4.26) mm Hg,P＜0.05],+dp/dtmax显著高于MI+ PBS组[（4616.63±363.34）mum Hg/s比(3912.75±248.79) mm Hg/s,P＜0.05],- dp/dtmax显著高于MI+ PBS组[(4254.63±324.34) mm Hg/s比（3530.88±309.71）mm Hg/s,P＜0.05]。(2)Ⅰ型和Ⅲ型胶原蛋白表达水平的检测结果：MI+ MSC组大鼠梗死区Ⅰ型和Ⅲ型胶原蛋白表达均显著高于MI+ PBS组,而非梗死区Ⅰ型和Ⅲ型胶原蛋白表达均显著低于MI+ PBS组（P均＜0.05）。结论 MSC通过促进MI大鼠梗死区胶原蛋白修复性合成,减少非梗死区胶原蛋白沉积,从而抑制心室重构,改善心脏功能。     

Corticosteroid Modulation of the Renin System and Blood Pressure in the Spontaneously Hypertensive Rat

This study examines the role of gluco- and mineralcorticoids in the regulation of the renin-angiotensin system and blood pressure in the spontaneously hypertensive rat (SHR). Effects of adrenalectomy and selective treatment with either aldosterone (30 μg/kg/day) or dexamethasone (60 μg/kg/day) on plasma renin substrate, active renin (PRA), total renin and blood pressure were studied in 10 week old SHR and control WKY rats. Systolic blood pressure was moderately lower in adrenalectomized rats (129±2 mm Hg vs 137±4 mm Hg in control WKY and 145±4 mm Hg vs 160±3 mm Hg in control SHR) but could be restored to the control range by aldosterone. Dexamethasone repletion induced substantial increments of systolic blood pressure to comparable levels in both species (202±8 mm Hg in WKY and 192±6 mm Hg in SHR). Renin substrate was markedly lower in adrenalectomized, saline repleted rats. This could be reversed by dexamethasone in both species and by aldosterone in WKY rats only. Both PRA and total renin were higher (p<0.01) in the adrenalectomized, saline repleted state. This increase was not observed in aldosterone repleted rats. However, dexamethasone inhibited the adrenalectomy associated increase of PRA and total renin in SHR but not in WKY rats. Differences in blood pressure between SHR and WKY persist even in adrenalectomized state despite comparable stimulation of the renin system. Conversely, while blood pressure of both species responds similarly to selective corticosteroids therapy, the response of the renin-angiotensin system in SHR and WKY rats is distinct. Therefore factors other than the adrenal gland and the renin system must be involved in the determination of the high blood pressure in SHR.     

肌浆网钙ATP酶基因转导对慢性心力衰竭犬心肌蛋白质组影响的初步研究

目的 分析心肌肌浆网Ca2+-ATP酶(sarcoplasmic reticulum Ca2+ ATPase 2a,SERCA2a)基因转导对慢性心力衰竭(HF)犬心肌蛋白质组的影响,探讨SERCA2a基因转导改善心功能的机制.方法 快速右心室起搏建立HF犬模型并随机分为HF组、HF+绿色荧光蛋白(enhanced green fluorescent pmtein,EGFP)组、HF+SERCA2a组.后两组分别向心肌内注射携带EGFP和SERCA2a基因的rAAV载体.于基因转导30 d时停止起搏后进行超声心动图和血流动力学检查并制备心室肌双向电泳蛋白样品和心肌双向电泳图谱,图像分析软件分析蛋白表达差异点,MALDI-TOF-MS数据库搜索鉴定蛋白质.结果 基因转导30 d时,HF+SERCA2a组犬的症状、超声心动图和血流动力学指标与HF+EGFP组相比有显著好转(P＜0.05);与对照组相比差异无统计学意义(P＞0.05).挑选SERCA2a基因转导后表达量发生明显改变的10个蛋白点进行分析,经质谱鉴定分别为心肌收缩相关蛋白、线粒体能量代谢酶类和应激相关蛋白.结论 以rAAV为载体介导SERCA2a基因转导能够改善HF犬心脏的收缩和舒张功能,其可能的机制是恢复了心肌收缩相关蛋白正常表型或正常表达量,增加了心肌能量的产生,改变了应激相关蛋白的表达.     

RNA干扰血管紧张素转换酶对自发性高血压大鼠血压及心肌重构的影响

目的 用RNA干扰技术下调血管紧张素转换酶(ACE)表达,观察其对自发性高血压大鼠血压及心肌重构的影响.方法 自发性高血压大鼠随机分为3组,即空白对照组(尾静脉注射生理盐水),病毒对照组(尾静脉注射对照腺病毒),治疗组[尾静脉注射表达ACE基因特异性短发夹RNA(shRNA)的重组腺病毒载体],同时设WKY正常血压对照组.以上各组大鼠均于实验的第1、16天各注射1次.干预前后检测尾动脉压的变化.于首次注射后第3天,用RT-PCR及Western blot法检测心肌、主动脉组织中ACE mRNA及蛋白的表达,ELISA法检测血清中ACE的含量.实验结束时,检测左心重/体重及心肌胶原蛋白的含量,并用透射电镜观察心肌超微结构的变化.结果 治疗组于每次注射后,尾动脉压均明显下降22 mm Hg(1 mm Hg=0.133 kPa)左右,单次注射后降压作用至少可持续14 d,累积降压幅度达38 mm Hg左右,而空白对照和病毒对照组血压则持续升高.治疗组心肌、主动脉组织中ACE mRNA及蛋白表达明显低于空白对照组和病毒对照组(P＜0.05),而与WKY组比较差异无统计学意义.治疗组血清ACE含量(16.37±3.90)ng/ml也明显低于空白对照组(48.26±1.50)ng/ml和病毒对照组(46.67±2.82)ng/ml,P＜0.05,而与WKY组(14.88±3.15)ng/ml比较差异无统计学意义.治疗组左心重/体重与心肌胶原蛋白含量[2.24±0.19与(1.283±0.019)μg/mg]明显低于空白对照组[3.21±0.13与(1.686±0.013)μg/mg]和病毒对照组[3.13±0.12与(1.682±0.009)μg/mg],P均＜0.05,但还未降到WKY组水平[2.06±0.11与(1.257±0.019)μg/mg].电镜观察显示治疗组心肌超微结构得到了明显改善.结论 RNA干扰可有效下调ACE表达,降低自发性高血压大鼠血压,改善心肌重构.RNA干扰有望成为高血压病基因治疗的新方法.