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Objective To observe the effects of the chronic adventitia injury on the vasoconstriction of the rat carotid artery. Methods A non-occlusive silicone collar was positioned around the right carotid artery of rats. Blood flow and vascular reactivity to 5-HT were examined, and both carotids were harvested for morphometry at day 3,7 and 14 after operation. Results In the early stage of advenfitia injury induced by positioning a silicone collar around file rat carotid artery, there appeared the characteristic histological changes of chronic vasospasm in collared artery, such as the reduction of the luminal area for （12.15±2.29）% at day 3 after operation （P =0.003 ） and （45.17±3.84）% at day 7 （P 〈 0.001 ）] ,corrugation of the internal elastic lamina,medial thickening up to [ （23.04±5.96）% at day 3 （P =0.009）, （61.65±10.32）% for day 7 （P 〈 0.001 ）] ,the reduction of the blood flow and the increase of vascular reactivity to 5-HT when compared to con- tralateral arteries. Two weeks after collar placement, the vascular wall remodeling was observed in injured artery, such as the medial thickening for [（31.52±4.56） %,P =0.012] and a diffuse intimal hyperplasia,the reduction of the lunfinal area [（37.17±4.57）% （P 〈 0.001）] and the carotid artery blood flow. The average neointima area was （0.19±0.05） rom2 in collared arteries. The vascular reactivity to 5-HT came back to the normal level. Conclusions Collar-induced advenfitia injury caused the enhancement of vascular contractility and the neointima formation. The change of vascular contractility appeared before the formation of neointima.
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BACKGROUND: At present, Doppler tissue imaging can be used extensively to make a quantitative assessment of left ventricular regional myocardial function. Postsystolic shortening is a delayed relaxation in regional myocardium following acute ischemia.OBJECTIVE: To observe longitudinal wall motion characteristics in left ventricular regional myocardiun and evaluate the clinical significance of postsystolic shortening in isovolumic relaxation period.DESIGN: Case-control observation.SETTING: Heart Center of Beijing Chaoyang Hospital.PARTICIPANTS: We selected 30 myocardial infarction inpatients hospitalized in the Heart Center of Beijing Chaoyang Hospital between April 2003 and September 2003 as myocardial infarction group; another 30 patients with non-cardiac diseases were set as control group. Subjects of the two groups volunteered in the experiment.METHODS: Dynamic images were collected and information was analyzed off-line. Left ventricular myocardial velocity and time velocity integral profiles were acquired along long axis asynchronously in basal and mid- segments of different walls. Peak velocity of isovolumic contraction period (VIC), ejection period (Ye), isovolumie relaxation period (VIR), rapid filling period (VRF) and atrial systole (VAS) and maximum time velocity integral (TVIMAX) in regional myocardium were measured.Doppler in different segments at longitudinal wall of myocardium in the the two groups.RESULTS: Thirty patients were recruited in myocardial infarction group and control group separately and all of them entered the result analysis ocardium was lower in myocardial infarction group than in control group,especially in infarcted segments, suggesting that the function of cardiac contraction and relaxation in patients with myocardial infarction was demyocardial isovolumic relaxation in myocardial infarction group, indicating period and isovolumic relaxation period in TVIMAX in myocardial infarction group.mal movement at isovolumic relaxation phase suggests the presence of postsystolic shortening and abnormal wall motion in regional myocardium.chemic myocardium.
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Objective By quantitative tissue velocity i maging(QTVI),to observe longitudinal wall motion characteristics during isovolumic contraction, ejection, isovolumic relaxation, early relaxation, atrial systole phases in regional myocardium of myocardial infarction patients with three diseased blood vessels, and to assess postsystolic shortening in isovolumic relaxation phase and its clinical meanings. Methods Left ventricular regional myocardium of 30 myocardial infarction patients (MI group) and 30 non-cardiac disease subjects (control group) was assessed by QTVI. After dynamic images were collected and information was analyzed off-line, left ventricular myocardial velocity and time velocity integral profiles were acquired along long axis asynchronously in basal and middle segments of different walls, peak velocities (V IC , V S, V IR , V E, V A) during different phases and maximum time velocity integral (TVI max )in regional myocardium was measured. Results Peak velocities(V IC , V S, V IR , V E, V A) in different segments of left ventricular regional myocardium in MI group were lower than those of control group, especially more obviously in infarcted segments. Peak velocity amplitude in ejection declined, but it had positive velocity spike; abnormal positive velocity in isovolumic relaxation phase suggested postsystolic shortening. What's more, time velocity integrals in some segments of MI group had two wave crests, reached maximum in isovolumic relaxation phase, but were still lower than that of control group. Conclusions Systolic and diastolic function in MI patients with three diseased blood vessels are apparently impaired; abnormal movement in isovolumic relaxation phase suggests existence of postsystolic shortening and abnormal wall motion in regional myocardium.V IR is a marker of abnormal regional wall motion and ischemic myocardium.
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Objective: Our aim was to investigate the effects of phenylephrine (PH) and angiotensin Ⅱ (AT) on reperfusion arrhythmias in the isolated rat heart and its mechanism. Methods: Isolated rat hearts were subjected to dual coronary perfusion. After 15 minutes of aerobic perfusion of both coronary beds, flow to the left coronary bed infused selectively into that bed. Ventricular tachycardia (VT) and fibrillation (VF) were analyzed 5 minutes after reperfusion. Results: The reperfusion arrhythmias was significantly exacerbated by PH; however, AT alone did not have the same effect. The selective Na+/H+ exchanger (NHE) inhibitor, HOE642, which was infused along with PH, reversed the proarrhythmic effects of PH. The specific protein kinase C (PKC) inhibitor GF109203X (GF) infused along with PH can only partially reverse the proarrhythmic effect of PH. The AT2 receptor inhibitor PD123319 (PD) alone increased the incidence of reperfusion-induced arrhythmias. However, no statistical significance showed. Combination of PD and AT significantly increased the incidence of reperfusion-induced arrhythmias. Conclusion: Activation of α1-adrenoceptor can exacerbate reperfusion-induced arrhythmias. The AT1 receptor activated by AT can exacerbate reperfusion-induced arrhythmias. The activation of AT2 receptor may reduce reperfusion-induced arrhythmias.
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AIM: To discuss the effects of matric metalloproteinasez and tissue inhibitor 1 (MMP2/TIMP1) on the vascular remodeling after angioplasty and the regulatory effect of tongxinluo on it in rabbits. METHODS: 65 male white rabbits (2.5-3.5 kg; 6-8 months) were divided into 4 groups: control group (n=5, normal diet ), injury group (n=20, normal diet plus intimal injury), high-lipid group (n=20, high cholesterol diet plus intimal injury) and tongxinluo group (n=20, tongxinluo 0.5 mg?kg~-1?d~-1, 4 weeks, also high cholesterol diet plus intimal injury). Under X-ray the narrow parts of the vessel underwent angioplasty. All rabbits were killed and vessel samples were excised, respectively, for the detection of histomorphometry immunohistochemically and RT-PCR. The data were expressed as ?s. RESULTS: (1) The change of vascular morphological results showed that the intimal area in tongxinluo group was less than that in high-lipid group (P
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Objective To investigate the effects of local delivery c-myc antisense oligodexynucleotides on neointimal hyperplasia after angioplasty in rabbits. Methods The celiac arterial endothelium of 75 male Japanese white rabbit (2.5?0.5 kg) were denuded after being fed with cholesterol-supplemented diet to establish the model of atherosclerotic stenosis of celiac arteries. The animals were randomized into the antisense DNA group (Group Ⅰ), sense DNA group (Group Ⅱ), saline control group (Group Ⅲ) and simple angioplasty group (Group Ⅳ). The drugs were injected intramurally using a porous balloon. The local vessels were collected at the 24 th hour and the 4 th week after the procedure for morphological observation. C-myc mRNA level was measured by means of RT-PCR and c-myc protein with immunohistochemical staining. Results RT-PCR showed that c-myc mRNA level in Group Ⅰ was lower than that of Group Ⅱ, Group Ⅲ and Group Ⅳ after the first 24 hours. The ratio of neointimal area (NEA) to medial area (MA) and NEA/MA in Group Ⅰ were significantly less than those of Group Ⅱ, Group Ⅲ and Group Ⅳ. Immunohistochemical staining showed that the percentage of c-myc protein positive cells was less in Group Ⅰ than those of the other groups. Conclusion Transcatheter local delivery of c-myc antisense oligonucleotides reduces neointimal hyperplasia after angioplasty in rabbits.
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Objective To investigate the clinical value of the intra-cronary interventional techniquein the treatment of coronary heart disease. Methods The 110 patients with coronary heart disease weretreated with 63 balloon angioplasties and 47 coronary-stent implantations. Results The ballloon angioplasty was made in 94 coronary lesion arteries with success of 88 vessels. In the following up periods of2-72 months, the angina pectoris and acute myocardial infarction were occurred respectively in 11 and2 cases (24.07 % ). The 63 stems were implanted into 59 coronary lesion arteries with success of 58 vessels. All patients were followed up for 2~12 months and the angina pectoris were occurred in 6 cases(13.3 % ). Conclusion The intracoronary intervetional technique was an effective method for treatmentof the coronary heart disease.