Résumé
Objective: To observe the effect of L-carniti ne (L-CN) in the treatment of congestive heart failure (CHF). Meth ods: Fifty-six cases of chronic CHF randomly received routine treatment (Digitalis, diuretics, vasodilator, ACEI or βblocker) or L-CN (3.0 g/d ,V D×10 d) with routine therapy. Results: The treatment efficiency of L-CN group and control group were 89.3% and 60.7% (P<0.01), respect ively. No adverse reactions related to the drug were observed. Conclusio n: L-CN with routine therapy might be a safe way to the treat CHF.
Résumé
Objective: To investigate the relationship between serum HGF levels and clinical severity of essential hypertension (EH). Methods: The serum HGF concentrations of 44 patients with EH were measur ed by ELISA. Results: The serum HGF levels in patients with EH w ere higher than that in control. Furthermore, the serum HGF levels of EH patient s with coronary atherosclerosis (CAS) were significantly higher than those of EH patients without CAS ［(920.8±250.0） pg/ml vs （747.9±132.1） pg/ml, P <0.01］ or control ［（643.8±98.2） pg/ml, P<0.01)］.The changes of HGF l evel were correlated with the clinical courses (r=0.63, P<0.01) and stag es (r=0.69, P<0.01) of hypertension. Conclusion: HGF may be considered as a new index for the severity of hypertension and an useful bio chemical parameter for estimating the development of atherosclerosis.
Résumé
Objective: To investigate the changes of myo cardial contractile function during myocardial stunning in calcium overload rats and the protective effects of tetrandrine. Methods: Forty-six rats were randomized into control, myocardial ischemia, myocardial stunning, low and high dose of tetrandrine groups. Another 10 rats were used to identify the calcium overload. vitamin D3 (0.3 million Unit/kg) and nicotinic acid were adm inistered. After 16 d when calcium overload occured, left anterior descending ar tery was ligated. Twenty minutes of myocardial ischemia followed by 60 min of re perfusion was induced. The contractile function parameters were determined dynam ically. At the end of experiment, myocardial cytosolic ［Ca2+］i was deter mined in various groups. In tetrandrine groups, tetrandrine (62.2 or 93.6 μmol/ kg ) was administered by gastrogavage daily.After 16 d, the rats undergone the e xperiments mentioned above. Results: Sixteen days after vitamin D3 , nicotinic acid were given, ［Ca2+］i increased by 2.6 folds (146.8±10.8 ) vs (368.5±22.6) nmol/L, (P<0.01). Whereas, ［Ca2+］i in tetrand rine groups were (210.8±16.4) and (198.6±15.3) nmol/L, which were significantl y lower than that of calcium overload group. Twenty minutes of myocardial ische mia resulted in the decrease of dp/dtmax and Vmax in all groups with the most si gnificant in stunning and calcium overload groups. The contractile function rest ored gradually after reperfusion. At all time points, dp/dtmax and Vmax in both tetrandrine groups were higher than those in both stunning and calcium overload groups. And effect with higher dose of tetrandrine were more significant than in low dose of tetrandrine. After 60 min of reperfusion, dp/dtmax in stunning, cal cium overload, low and high dose of tetrandrine groups were 49.7%, 51.5%, 71.0% and 83.4% of that in control, respectively， and Vmax were 55.0%, 49.8%, 73.9% and 77.5% of that in control, respectively. Conclusion: T he myocardial contractile function in vitamin D3-induced calcium overload gro up is impaired. On basis of myocardiocyte calcium overload, transient ischemia l eads to myocardial stunning. At the stage of ischemia, the impaired degree of my ocardial contractile function is similar to that in stunning group, suggesting a t this stage the effect of ischemia on myocardial function is greater than that of calcium overload. Tetrandrine chronically improves the myocardial function in Vitamin D3-induced calcium overload rats.
Résumé
Objective: To investigate whether there is additi ve effects of hyperinsulinemia and ischemia on expression of canine myocardial G LUT4 gene in vivo. Methods: The expression of myocardial GLU T4 was determined by semiquantitative immunoblotting.The expression of GLUT4 mRN A was determined by semiquantitative Northern blotting. Results: Dramatic changes were seen in GLUT4 mRNA and GLUT4 expression in the ischemic hearts.After infusing insulin for 8 h,regional GLUT4 mRNA and GLUT4 levels in is chemic hearts were 2.5, 2.3-fold that of expression in normal hearts(P<0.01 ). Myocardial glucose uptake in ischemic hearts was increased by 4-fold when co mpared with normal hearts(P<0.01). Conclusion: There are not only additive effects of hyperinsulinemia and low-flow ischemia on canine myoc ardial GLUT4 mRNA and GLUT4 expression in vivo, but also increase of myocar dial glucose uptake. Enhanced GLUT4 expression may be an important protective m echanism by which myocardial cells enhance glucose uptake and metabolism during low-flow ischemia.
Résumé
Objective: To investigate whether insulin stimulates the translocation of glucose transporter-4 (GLUT4) and glucose uptak e in ischemic myocardium. Methods: Plasma concentration of gluc ose, lactate, free fatty acid and insulin were determined by autoanalyser, and G LUT4 was studied by Western blotting analysis. Results: Insulin increased GLUT4 significantly in sarcolemma of ischemic myocardium ［(25±4)% vs (40±6)%］, and GLUT4 content in intracellular membrane decreased proporti onally. The glucose uptake increased significantly in insulin-ischemic myocardi um. The uptake of insulin-ischemic myocardium was almost 2 times that of ischem ic myocardium. Conclusion: Insulin stimulation results in GLUT4 translocation and increases glucose uptake in ischemic myocardium. When myocardi al ischemia occurs, insulin is helpful in increasing myocardial glucose uptake a nd utilization.
Résumé
Objective：To investigate the mechanism of increased glucose uptake, the expression of myoc ardial glucose transporter1 (GLUT1) was determined after low-flow myocardial is chemia. Methods： An in vivo open-chest canine model of low -flow myocardial ischemia was used to correlate myocardial glucose uptake with the number of GLUT1. The expression of myocardial GLUT1 glucose transporter was determined by semiquantitative Northern blotting and immunoblotting. Res ults： GLUT1 mRNA and GLUT1 polypeptide expression was substantially inc reased in ischemic region from the experimental hearts when compared to normal h earts. There was no significant regional difference in GLUT1 expression in eith er normal or ischemic hearts.Conclusion：Myocardial ischemia ind uces a factor or factors which stimulate GLUT1 expression in ischemic myocardial regions. Enhanced GLUT1 expression may be an important protective mechanism by which myocardial cells enhance glucose uptake and metabolism during low-flow my ocardial ischemia.
Résumé
Objective: To observe the effect of L-carniti ne (L-CN) in the treatment of congestive heart failure (CHF). Meth ods: Fifty-six cases of chronic CHF randomly received routine treatment (Digitalis, diuretics, vasodilator, ACEI or βblocker) or L-CN (3.0 g/d ,V D×10 d) with routine therapy. Results: The treatment efficiency of L-CN group and control group were 89.3% and 60.7% (P<0.01), respect ively. No adverse reactions related to the drug were observed. Conclusio n: L-CN with routine therapy might be a safe way to the treat CHF.
Résumé
Objective: To investigate the relationship between serum HGF levels and clinical severity of essential hypertension (EH). Methods: The serum HGF concentrations of 44 patients with EH were measur ed by ELISA. Results: The serum HGF levels in patients with EH w ere higher than that in control. Furthermore, the serum HGF levels of EH patient s with coronary atherosclerosis (CAS) were significantly higher than those of EH patients without CAS ［(920.8±250.0） pg/ml vs （747.9±132.1） pg/ml, P <0.01］ or control ［（643.8±98.2） pg/ml, P<0.01)］.The changes of HGF l evel were correlated with the clinical courses (r=0.63, P<0.01) and stag es (r=0.69, P<0.01) of hypertension. Conclusion: HGF may be considered as a new index for the severity of hypertension and an useful bio chemical parameter for estimating the development of atherosclerosis.
Résumé
Objective: To investigate the changes of myo cardial contractile function during myocardial stunning in calcium overload rats and the protective effects of tetrandrine. Methods: Forty-six rats were randomized into control, myocardial ischemia, myocardial stunning, low and high dose of tetrandrine groups. Another 10 rats were used to identify the calcium overload. vitamin D3 (0.3 million Unit/kg) and nicotinic acid were adm inistered. After 16 d when calcium overload occured, left anterior descending ar tery was ligated. Twenty minutes of myocardial ischemia followed by 60 min of re perfusion was induced. The contractile function parameters were determined dynam ically. At the end of experiment, myocardial cytosolic ［Ca2+］i was deter mined in various groups. In tetrandrine groups, tetrandrine (62.2 or 93.6 μmol/ kg ) was administered by gastrogavage daily.After 16 d, the rats undergone the e xperiments mentioned above. Results: Sixteen days after vitamin D3 , nicotinic acid were given, ［Ca2+］i increased by 2.6 folds (146.8±10.8 ) vs (368.5±22.6) nmol/L, (P<0.01). Whereas, ［Ca2+］i in tetrand rine groups were (210.8±16.4) and (198.6±15.3) nmol/L, which were significantl y lower than that of calcium overload group. Twenty minutes of myocardial ische mia resulted in the decrease of dp/dtmax and Vmax in all groups with the most si gnificant in stunning and calcium overload groups. The contractile function rest ored gradually after reperfusion. At all time points, dp/dtmax and Vmax in both tetrandrine groups were higher than those in both stunning and calcium overload groups. And effect with higher dose of tetrandrine were more significant than in low dose of tetrandrine. After 60 min of reperfusion, dp/dtmax in stunning, cal cium overload, low and high dose of tetrandrine groups were 49.7%, 51.5%, 71.0% and 83.4% of that in control, respectively， and Vmax were 55.0%, 49.8%, 73.9% and 77.5% of that in control, respectively. Conclusion: T he myocardial contractile function in vitamin D3-induced calcium overload gro up is impaired. On basis of myocardiocyte calcium overload, transient ischemia l eads to myocardial stunning. At the stage of ischemia, the impaired degree of my ocardial contractile function is similar to that in stunning group, suggesting a t this stage the effect of ischemia on myocardial function is greater than that of calcium overload. Tetrandrine chronically improves the myocardial function in Vitamin D3-induced calcium overload rats.
Résumé
Objective: To investigate whether there is additi ve effects of hyperinsulinemia and ischemia on expression of canine myocardial G LUT4 gene in vivo. Methods: The expression of myocardial GLU T4 was determined by semiquantitative immunoblotting.The expression of GLUT4 mRN A was determined by semiquantitative Northern blotting. Results: Dramatic changes were seen in GLUT4 mRNA and GLUT4 expression in the ischemic hearts.After infusing insulin for 8 h,regional GLUT4 mRNA and GLUT4 levels in is chemic hearts were 2.5, 2.3-fold that of expression in normal hearts(P<0.01 ). Myocardial glucose uptake in ischemic hearts was increased by 4-fold when co mpared with normal hearts(P<0.01). Conclusion: There are not only additive effects of hyperinsulinemia and low-flow ischemia on canine myoc ardial GLUT4 mRNA and GLUT4 expression in vivo, but also increase of myocar dial glucose uptake. Enhanced GLUT4 expression may be an important protective m echanism by which myocardial cells enhance glucose uptake and metabolism during low-flow ischemia.
Résumé
Objective: To investigate whether insulin stimulates the translocation of glucose transporter-4 (GLUT4) and glucose uptak e in ischemic myocardium. Methods: Plasma concentration of gluc ose, lactate, free fatty acid and insulin were determined by autoanalyser, and G LUT4 was studied by Western blotting analysis. Results: Insulin increased GLUT4 significantly in sarcolemma of ischemic myocardium ［(25±4)% vs (40±6)%］, and GLUT4 content in intracellular membrane decreased proporti onally. The glucose uptake increased significantly in insulin-ischemic myocardi um. The uptake of insulin-ischemic myocardium was almost 2 times that of ischem ic myocardium. Conclusion: Insulin stimulation results in GLUT4 translocation and increases glucose uptake in ischemic myocardium. When myocardi al ischemia occurs, insulin is helpful in increasing myocardial glucose uptake a nd utilization.
Résumé
Objective：To investigate the mechanism of increased glucose uptake, the expression of myoc ardial glucose transporter1 (GLUT1) was determined after low-flow myocardial is chemia. Methods： An in vivo open-chest canine model of low -flow myocardial ischemia was used to correlate myocardial glucose uptake with the number of GLUT1. The expression of myocardial GLUT1 glucose transporter was determined by semiquantitative Northern blotting and immunoblotting. Res ults： GLUT1 mRNA and GLUT1 polypeptide expression was substantially inc reased in ischemic region from the experimental hearts when compared to normal h earts. There was no significant regional difference in GLUT1 expression in eith er normal or ischemic hearts.Conclusion：Myocardial ischemia ind uces a factor or factors which stimulate GLUT1 expression in ischemic myocardial regions. Enhanced GLUT1 expression may be an important protective mechanism by which myocardial cells enhance glucose uptake and metabolism during low-flow my ocardial ischemia.