Effect of tongxinluo on endothelin-1 in the mini-swine model of acute myocardial infarction and reperfusion / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To evaluate the change of endothelin-1 (ET-1) in the mini-swine model of acute myocardial infarction (AMI) and reperfusion and the effect of Tongxinluo (TXL) on it, and to explore the possible mechanism of no-reflow.</p><p><b>METHODS</b>Forty mini-swines were randomized into 5 groups: the model group, the small,middle and large dose of TXL groups and the sham-operated group, 8 in each group. The AMI reperfusion model was established by coronary ligation for 3 hrs followed with relaxation for 1 hr. Plasma ET-1 content before and after AMI, and after reperfusion was determined respectively by radioimmunoassay. The ET-1 mRNA expression in myocardial tissue of normal, ischemic and no-reflow area were respectively quantified by reverse transcription-polymerase chain reaction.</p><p><b>RESULTS</b>(1) Compared with before AMI, levels of plasma ET-1 at the time points of 5 min and 3 hrs after AMI, 5 min and 1 hrs after reperfusion in the model group were significantly raised, showing an increasing tendency (all P < 0.01). But the increment in the middle and large dose of TXL groups were all lower than that in the model group (P < 0.05). (2) In the model and the TXL groups, levels of ET-1 in myocardial tissue of ischemic and no-reflow area were significantly higher than those in the normal area, and the increment in no-reflow area was higher than that in ischemic area (all P < 0.01). Compared with the model group, significant lowering of ET-1 in ischemic area was only shown in the middle and large dose of TXL groups (P < 0.01). (3) In the model and the TXL groups, ET-1 mRNA expression in ischemic area was significantly higher (all P < 0.01), while it in no-reflow area was significantly lower than that in the normal area respectively (all P < 0.01). The raised ET-1 mRNA expression in the middle and large dose TXL groups was significantly lowered when compared with that in the model group (P < 0.01).</p><p><b>CONCLUSION</b>The endothelium injury might be one of the important mechanisms for no-reflow phenomenon. TXL might reduce the no-reflow by protecting endothelium cells. was significantly higher (all P < 0.01), while it in no-reflow area was significantly lower than that in the normal area respectively (all P < 0.01). The raised ET-1 mRNA expression in the middle and large dose TXL groups was significantly lowered when compared with that in the model group (P < 0.01). Conclusion The endothelium injury might be one of the important mechanisms for no-reflow phenomenon. TXL might reduce the no-reflow by protecting endothelium cells.</p>

Comparison of three doses of enalapril in preventing left ventricular remodeling after acute myocardial infarction in the rat / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To compare the effects of high, middle and low doses of enalapril in preventing left ventricular remodeling (LVRM) after acute myocardial infarction (AMI) in rats, especially evaluating the efficacy of low dose enalapril.</p><p><b>METHODS</b>AMI was induced by ligating the left coronary artery in 149 female SD rats. 48 hours after the procedure, the 97 surviving rats were randomized to one of the following four groups: (1) AMI controls (n = 24), (2) high-dose (10 mg x kg(-1) x d(-1), n = 25), (3) middle-dose (1 mg x kg(-1) x d(-1), n = 23), and (4) low-dose (0.1 mg x kg(-1) x d(-1), n = 25) enalapril groups. In addition, sham-operated (n = 13) and normal rats (n = 10) were randomly selected to serve as non-infarction controls. Enalapril was delivered by direct gastric gavage. After 4 weeks of therapy, hemodynamic studies were performed, then the rat hearts were fixed with 10% formalin and pathology analysis was performed. Exclusive of the dead rats and those with MI size < 35% or > 55%, complete experimental data were obtained from 67 rats, which were comprised of (1) AMI controls (n = 13), (2) high-dose enalapril (n = 13), (3) middle-dose enalapril (n = 12), (4) low-dose enalapril (n = 12), (5) sham-operated (n = 8) and (6) normal (n = 9) groups.</p><p><b>RESULTS</b>There were no significant differences among the four AMI groups in infarction size (all P > 0.05). Compared with the sham-operated group, the left ventricular (LV) end diastolic pressure (LVEDP), volume (LVV), absolute and relative weight (LVAW, LVRW) in AMI group were all significantly increased (all P < 0.001), while maximum LV pressure rising and dropping rates (+/- dp/dt) and their corrected values by LV systolic pressure (+/- dp/dt/LVSP) were all significantly reduced in the AMI control group (P < 0.01 - 0.001), indicating LVRM occurred and LV systolic and diastolic functions were impaired. Compared with the AMI group, LVEDP, LVV, LVAW and LVRW were all significantly decreased in the three enalapril groups (control P < 0.001), with the reduction of LVEDP, LVV and LVAW being more significant in high-dose than in low-dose enalapril groups (all P < 0.05), and the +/- dp/dt/LVSP were significantly increased only in the high and middle-dose enalapril groups (P < 0.01).</p><p><b>CONCLUSIONS</b>High, middle and low doses of enalapril were all effective in preventing LVRM after AMI in the rat, with low dose enalapril being effective and high dose superior. As for LV functional improvement, only high and middle-dose enalapril were effective.</p>

Protective effects of tongxinluo, carvedilol and valsartan on microvascular endothelial function and integrity after late reperfused AMI in rabbits / 中国病理生理杂志

AIM: To compare the protective effects of tongxinluo, a Chinese medicine, and carvedilol and valsartan on myocardium microvascular endothelial function and integrity after late reperfusion of acute myocardial infarction (AMI) in rabbits. METHODS: Forty-eight rabbits were randomly assigned to the following groups: (1) sham operated rabbits; (2) ischemia-reperfusion (I-R) controls; (3) tongxinluo (1.0 g?kg~ -1?d~ -1); (4) carvedilol (5 mg?kg~ -1?d~ -1); (5) valsartan (10 mg?kg~ -1?d~ -1) and (6) ticlopidine + aspirine (30 and 20 mg?kg~ -1?d~ -1, respectively) groups. After 3 d of drug treatment, the left coronary artery in the rabbit was ligated for 2 h and loosed subsequently for another 2 h. The serum levels of nitric oxide (NO_2~-/NO_3~-) and endothelin (ET) at baseline before AMI, 2 h after both AMI and reperfusion were examined. Also, the number of circulating endothelial cells (CEC), MI size and percentage myocardium focal bleeding incidence were determined 2 h after reperfusion. RESULTS: (1) The baseline level of NO_2~-/NO_3~- was significantly higher in tongxinluo group than that in other groups (all P

Accuracy of low dose dobutamine,isosorbide dinitrate alone and in combination stress echocardiography for identifying viable myocardium in patients with old myocardial infarction and severe left ventricular dysfunction:compared with ~(99m)Tc-MIBI/~(18)FDG / 中华超声影像学杂志

(0.05)). The sensitivity and the agreement rate were best at dose of Dob 10 ?g?kg~(-1)?min~(-1) with (86.5)% and (86.5)% (Kappa(0.71)), respectively. When Isoket combined with Dob 3,5 ?g?kg~(-1)?min~(-1), the sensitivities and the agreement rates were both significantly improved than either one used (both P