Electroacupuncture improves neurovascular unit reconstruction by promoting collateral circulation and angiogenesis

Acupuncture at Shuigou（GV26） shows good clinical efficacy for treating stroke, but its mechanism remains poorly understood. In this study, a cerebral infarction model of ischemia/reperfusion injury received electroacupuncture at GV26（15 Hz and 1 m A, continuous wave [biphasic pulses], for 5 minutes）. Electroacupuncture effectively promoted regional cerebral blood flow on the infarct and non-infarct sides, increased infarct lesions, lectin, and number of blood vessels, upregulated von Willebrand factor and cell proliferation marker Ki67 expression, and diminished neurological severity score. These findings confirm that electroacupuncture at GV26 promotes establishment of collateral circulation and angiogenesis, and improves neurological function.

64-row multidetector computed tomography portal venography of gastric variceal collateral circulation

AIM:To study characteristics of collateral circulation of gastric varices (GVs) with 64-row multidetector computer tomography portal venography (MDCTPV).METHODS:64-row MDCTPV with a slice thickness of 0.625 mm and a scanning field from 2 cm above the tracheal bifurcation to the lower edge of the kidney was performed in 86 patients with GVS diagnosed by endoscopy. The computed tomography protocol included unenhanced,arterial and portal vein phases. The MDCTPV was performed on an AW4.3 workstation. GVs were classified into three types according to Sarin's Classification. The afferent and efferent veins of each type of GV were observed.RESULTS:The afferent venous drainage originated mostly from the left gastric vein alone (LGV) (28/86,32.59%),or the LGV more than the posterior gastric vein/short gastric vein [LGV > posterior gastric vein/short gastric vein (PGV/SGV)] (22/86,25.58%),as seen by MDCTPV. The most common efferent venousdrainage was via the azygos vein to the superior vena cava (53/86,61.63%),or via the gastric/splenorenal shunt (37/86,43.02%) or inferior phrenic vein (8/86,9.30%) to the inferior vena cava. In patients with gastroesophageal varices type 1,the afferent venous drainage of GV mainly originated from the LGV or LGV > PGV/SGV (43/48,89.58%),and the efferent venous drainage was mainly via the azygos vein to the super vena cava (43/48,89.58%),as well as via the gastric/splenorenal shunt (8/48,16.67%) or inferior phrenic vein (3/48,6.25%) to the inferior vena cava. In patients with gastroesophageal varices type 2,the afferent venous drainage of the GV mostly came from the PGV/SGV more than the LGV (PGV/SGV > LGV) (8/16,50%),and the efferent venous drainage was via the azygos vein (10/16,62.50%) and gastric/splenorenal shunt (9/16,56.25%). In patients with isolated gastric varices,the main afferent venous drainage was via the PGV/SGV alone (16/22,72.73%),and the efferent venous drainage was mainly via the gastric/splenorenal shunt (20/22,90.91%),as well as the inferior phrenic vein (3/23) to the inferior vena cava. CONCLUSION:MDCTPV can clearly display the afferent and efferent veins of all types of GV,and it could provide useful reference information for the clinical management of GV bleeding.

Inferior vena cava obstruction and collateral circulation as unusual manifestations of hepatobiliary cystadenocarcinoma

BACKGROUND: Hepatobiliary cystadenocarcinoma represents a rare epithelial malignant tumor derived from the intrahepatic bile duct. METHODS: A 71-year-old woman, who had undergone laparoscopic drainage of a cystic lesion of the right hepatic lobe, was misdiagnosed as having hepatic echinococcal disease, and received intracystic infusion of 95% ethanol four years ago. She was admitted to our hospital for further treatment. RESULTS: Physical examination revealed dilated superficial veins across the right abdominal wall. After mapping the direction of blood flow in these vessels, we assumed that this was a sign of inferior vena cava obstruction. Abdominal ultrasound, computed tomography, magnetic resonance imaging combined with magnetic resonance angiography showed a large cystic mass in the right upper quadrant and epigastrium, displacing the adjacent structures, adherent to the inferior vena cava, which was not patent, resulting in dilation of superficial epigastric veins. The patient underwent an exploratory laparotomy. Total excision of the huge mass measuring 16×15 cm was possible under selective vascular exclusion of the liver. Removal of the tumor resulted in immediate restoration of flow in the inferior vena cava. On the basis of the pathology and findings of immunohistochemical analysis, a hepatobiliary cystadenocarcinoma was diagnosed.CONCLUSIONS: In the present case, hepatobiliary cystadenocar-cinoma was accompanied by dilated superficial venous collaterals due to inferior vena cava obstruction. Selective vascular exclusion of the liver allowed a safe oncological resection of the tumor.

The Relationships between Serum Concentration of IGF-I and Left Ventricular Function as well as Coronary Collateral Circulation in Patients with Coronary Artery Disease

Objective To investigate therelationships between serum concentration of insulin -like growth factor - I (IGF-I) and left ventricular function as well as coronary collateral circulation in patients with coronary artery disease (CAD) . Methods In 41 patients with CAD and 15 control subjects without CAD, the concentrations of serum IGF - I were measured using radioimmunoassay. The relationships between the concentration of serum IGF - I and Leaman coronary artery score, Rentrop grade of coronary collateral circulation, left ventricular ejection fraction (LVEF) as well as left ventricular wall motion Cortina score were assessed. Results 1. There was no significant difference in the mean level of serum IGF -I between the CAD group and the control group (107. 92±44.74 ng/ml vs 113.05 ±33. 65 ng/ml, P> 0. 05), but the IGF - I concentrations in the subgroup with collateral circulation were significantly greater than that in the control group (147. 33 ±29. 92 ng/ml vs 113. 05±33. 65 ng/ml, P < 0. 01) or in the subgroup without collateral circulation (147. 33 ±29. 92 ng/ml vs 80. 01±29. 75 ng/ml , P < 0. 01). 2. The serum concentration of IGF -I had no significant correlation to the Leaman coronary artery score. 3. The serum level of IGF -I had significantly positive correlation to both LVEF ( r = 0. 45, P < 0. 001) and the Rentrop grade of coronary collateral circulation ( r = 0. 74, P < 0. 001), and was negatively related to the left ventricular wall motion Cortina score (r = -0. 53, P < 0. 001). 4. The Leaman coronary artery score had no significant correlation to the Rentrop grade of coronary collateral circulation. 5. The Leaman coronary artery score was related to neither the LVEF nor the Cortina score in the whole CAD group. In the subgroup without coronary collateral circulation, however, the Leaman score had significantly negative correlation to LVEF ( r = - 0. 46, P < 0. 05) and positive correlation to the Cortina score (r = 0. 47, P < 0. 05) . Conclusions The serum concentration of IGF -I was associated with both left ventricular function and coronary collateral circulation in patients with CAD. IGF -I may play a role in promoting coronary collateral circulation and in protecting left ventricular function in patients with coronary artery disease.

Intermittent appearance of right coronary fistula and collateral circulation:A case report

BACKGROUND Congenital coronary artery fistula can lead to symptoms of chest tightness,chest pain,or exertional dyspnea,which is a congenital vascular malformation that should not be ignored.Patients who have such malformations are frequently observed with different concurrent abnormal anatomic structures.Collateral circulation may have a positive effect on improving the patients'symptoms.CASE SUMMARY A 53-year-old female experienced episodic chest discomfort for the past month with symptoms manifesting when she was agitated or overexerted.After a positive treadmill test,the patient underwent coronary angiography.“Ghostlike”intermittent appearance of coronary ventricular fistula and collateral branching were observed.The patient was diagnosed with a right coronary ventricular fistula and collateral circulation.CONCLUSION This case shows the likelihood of collateral circulation in patients with coronary artery fistula.This may provide medical staff with novel solutions to treat insufficiency of myocardial blood supply induced by cardiovascular malformations.

Visfatin and 25-Hydroxyvitamin D_(3) Levels Affect Coronary Collateral Circulation Development in Patients with Chronic Coronary Total Occlusion

Background:Coronary collateral circulation(CCC)plays a vital role in the myocardial blood supply,especially for ischemic myocardium.Evidence suggests that the visfatin and 25-hydroxyvitamin D_(3)[25(OH)D_(3)]levels are related to the degree and incidence of vascular stenosis associated with coronary artery disease;however,few studies have evaluated the effect of visfatin and 25(OH)D_(3) on CCC development in patients with chronic total occlusion(CTO).This study aimed to evaluate the relationship between the serum visfatin and 25(OH)D_(3) levels and CCC in patients with CTO.Methods:A total of 189 patients with CTO confirmed by coronary angiography were included.CCC was graded from 0 to 3 according to the Rentrop-Cohen classification.Patients with grade 0 or grade 1 collateral development were in-cluded in the poor CCC group(n=82),whereas patients with grade 2 or grade 3 collateral development were included in the good CCC group(n=107).The serum visfatin and 25(OH)D_(3) levels were measured by ELISA.Results:The visfatin level was significantly higher in the poor CCC group than in the good CCC group,and the 25(OH)D_(3) level was significantly lower in the poor CCC group than in the good CCC group(P=0.000).Correlation analysis showed that the Rentrop grade was negatively correlated with the visfatin level(r=−0.692,P=0.000)but positively correlated with the 25(OH)D_(3) level(r=0.635,P=0.000).Logistic regression analysis showed that the vis-fatin and 25(OH)D_(3) levels were independent risk factors for CCC(odds ratio 1.597,95%confidence interval 1.300-1.961,P=0.000 and odds ratio 0.566,95%confidence interval 0.444-0.722,P=0.000,respectively).The visfatin and 25(OH)D_(3) levels can effectively predict the CCC status.Conclusion:Serum visfatin and 25(OH)D_(3) levels are related to CCC development and are independent predictors of poor CCC.

Infuences of Previous Angina Pectoris on Coronary Collateral Circulation and Left Ventricular Function in Patients with Acute Myocardial Infarction

Objective To investigate the influences of previous angina pectoris on coronary collateral circulation and left ventricular function in patients with acute myocardial infarction. Methods 307 patients with a first episode acute myocardial infarction underwent selective coronary angiography and left ventriculography. The relation of previous angina pectoris to coronary collateral circulation, peak creatine kinase and left ventricular function were analyzed. Results ①In the 307 patients, there were 192 (62. 5 % ) with previous angina [PA ( + ) group] and 115 (37. 5 % ) without [PA (-) group]. ②The peak creatine kinase (CK) and CK -MB were significantly higher in PA (-) group than in PA (+) group ( P < 0. 05 for both comparisons) . ③ Collateral circulation to infarct - related artery was more likely to be present in PA ( + ) group than in PA (-) group ( P < 0. 05) . (4) The left ventricular ejection fraction was significantly increased, and the left ventricular wall motion Cortina score decreased, in PA (+) group than in PA (-) group ( P < 0. 01 for both comparisons) . Conclusion In patients with acute myocardial infarction, previous angina pectoris may have beneficial effects on coronary collateral circulation and left ventricular function.

Influence of preoperative coronary collateral circulation on in-hospital mortality in patients undergoing coronary artery bypass graft surgery with intra-aortic balloon pump support

Background Outcomes in patients requiring coronary artery bypass graft （CABG） surgery have been improved with devices such as the intra-aortic balloon pump （IABP）.Good coronary collateral circulation （CCC） has been shown to reduce mortality in patients with coronary artery disease （CAD）.We aimed to investigate whether poor preoperative CCC grade is a predictor of in-hospital mortality in CABG surgery requiring IABP support.Methods Fifty-five consecutive patients who were undergoing isolated first time on-pump CABG surgery with IABP support were enrolled into this study and CCC of those patients was evaluated.Results Twenty-seven patients had poor CCC and 28 patients had good CCC.In-hospital mortality rate in poor CCC group was significantly higher than good CCC group （14 （50％） vs.4 （13％）,P=0.013）.Preoperative hemoglobin level （OR：0.752; 95％ CI,0.571-0.991,P=0.043）,chronic obstructive pulmonary disease （OR：6.731; 95％ CI,1.159-39.085,P=0.034） and poor CCC grade （OR：5.750; 95％ CI,1.575-20.986,P=0.008） were associated with post-CABG in-hospital mortality.Poor CCC grade （OR：4.853; 95％ CI,1.124-20.952,P=0.034） and preoperative hemoglobin level （OR：0.624; 95％ CI,0.476-0.954,P=0.026） were independent predictors of in-hospital mortality after CABG.Conclusion Preoperative poor CCC and hemoglobin are predictors of in-hospital mortality after CABG with IABP support.

Effect of Salvia Miltiorrhiza on Coronary Collateral Circulation in Dogs with Experimental Acute Myocardial Infarction

Summary: To evaluate the effect of Salvia Miltiorrhiza on coronary collateral circulation in dogs with experimental acute myocardial infarction, 12 dogs were randomly divided into Salvia Miltiorrhiza group (group D) and control group (group C). Acute myocardial infarction model was established in all dogs, Salvia Miltiorrhiza or saline was administered to the 2 groups respectively for 21 days. Coronary angiography was performed before and after ligation of coronary artery. The capillaries and distribution vessel density in tissue sections of myocardia were assessed. Angiography 2 h and 22 days after ligation of coronary artery revealed significant augmentation of collateral vessels, and capillaries and distribution vessel density in ischemic zone on day 22 showed statistically significant augmentation in group D as compared with that of controls ( P <0. 05 and P <0. 01). It is concluded that Salvia Miltiorrhiza might improve the opening and formation of coronary collateral circulation of ischemic myocardia in dogs and thereby protecting myocardia from ischemia.

The predictive value of coronary collateral circulation in patients with one or more coronary artery occlusion undergoing elective PCI

Background The coronary collateral circulation has a positive effect on the ischemic myocardium. But it is limited for patients missing the time window of total occlusion of the coronary artery elective percutaneous coronary intervention （PCI）. The effect of collateral circulation on left cardiac function has been less studied. Methods A total of 34 patients with one or more coronary artery occlusion who underwent coronary angiography and Rentrop＇ s method were divided into 2 groups： Good collateral circulation （A groups, Rentrop score 2-3, n= 19） and （B groups, Rentrop score 1-2, n=15）. The improvement of left ventricular end diastolic volume （LVEDV） and left ventricular ejection fraction （LVEF） were compared between the two groups before and after PCI. Results In good collateral circulation group, left ventricular ejection fraction （LVEF） was significantly higher after PCI（P〈O.05）. In poor collateral circulation group, left ventricular end diastolic volume index （LVEDV） was significantly increased after PCI （P〈O.05）. Conclusions Good collateral circulation has a signifi- cant protective effect on left ventricular function. PCI operation can significantly improve the prognosis of patients with good collateral circulation of coronary artery occlusion.

Idiopathic steno-occlusive disease with bilateral internal carotid artery occlusion:A Case Report

BACKGROUND Moyamoya disease(MMD)is a rare cause of acute stroke and transient ischemic attacks in children.We described clinical,diagnostic features and follow-ups of a young child with acute stroke.CASE SUMMARY We report a 4-year-old girl with left hemiparesis after an acute ischemic stroke.Her history was also significant for repeated left or right focal motor seizures,generalized tonic-clonic convulsions and transient ischemic attacks.Her magnetic resonance imaging and computed tomography(CT)of the brain and magnetic resonance angiography,CT angiography and venography on the cerebral vessels revealed evidence of bilateral fronto-parietal ischemic infarctions,occlusion of the right and left internal carotid arteries started at its bifurcation and non-visualization of right and left anterior and middle cerebral arteries.There was evidence of progression in angiography manifested as development of collaterals from the basal perforating vessels,increase in the extent of large intracranial arterial stenosis/occlusion and extensive collateral circulation with predominance from the posterior circulation.Physical and neurological evaluation and comprehensive laboratory investigations excluded an obvious comorbid disease or risk factor for the child’s condition.The diagnosis of MMD was highly suggested as a cause of the child’s steno-occlusive condition.She was treated symptomatically with levetiracetam,an antiepileptic medication.Aspirin was prescribed for secondary prevention.Her clinical manifestations were improved during the three years of follow-up.Revascularization surgery was postponed.CONCLUSION Up to our knowledge,this is the first report for MMD in a child in our country.The clinical improvement and the stabilization of the child’s condition over the 3 years of follow-up could be attributed to the rapid and extensive recruitment of collaterals and absence of risk factors or comorbidities.Revascularization surgery is highly recommended.

Predictors of short-term outcome in patients with acute middle cerebral artery occlusion: unsuitability of fluid-attenuated inversion recovery vascular hyperintensity scores

Fluid-attenuated inversion recovery （FLAIR） vascular hyperintensity （FVH） is used to assess leptomeningeal collateral circulation, but clinical outcomes of patients with FVH can be very different. The aim of the present study was to assess a FVH score and explore its relationship with clinical outcomes. Patients with acute ischemic stroke due to middle cerebral artery M1 occlusion underwent magnetic resonance imaging and were followed up at 10 days （National Institutes of Health Stroke Scale） and 90 days （modified Rankin Scale） to determine short-term clinical outcomes. Effective collateral circulation indirectly improved recovery of neurological function and short-term clinical outcome by extending the size of the pial penumbra and reducing infarct lesions. FVH score showed no correlation with 90-day functional clinical outcome and was not sufficient as an independent predictor of short-term clinical outcome.

Restrictive Effect of Puerarin on Myocardial Infarct Area in Dogs and Its Possible Mechanism

Summary: To evaluate the protective effect of puerarin on ischemic myocardium in dogs with acute myocardial infarction (AMI) and to reveal its possible mechanism, 10 dogs were randomly divided into puerarin group (group G) and control group (group C). AMI model was established in all dogs. Puerarin or saline was administered over a period of 21 days. Coronary angiography was performed before and after ligation of coronary artery. Eight hemorheological parameters were examined before and 22 days after the operation. The infarct area and vessel density of myocardium were assessed. The infarct area in group G was smaller than that in group C. Angiography 2 h and 22 d after ligation of coronary artery revealed significant augmentation of collateral vessels in group G as compared with control group. The platelet aggregation and the blood viscosity were in- creased during AMI when compared with control phase, and the increased indexes during AMI would be inhibited when puerarin were given. Capillaries and distribution vessel density in is- chemic zone on day 22 showed statistically significant augmentation in group G as compared with control group. Puerarin might improve the opening and formation of coronary collateral circula- tion, and might inhibit the increase of platelet aggregation and the blood viscosity during AMI, and thereby improve microcirculation and restrict myocardial infarct area.

Staged management of Budd-Chiari syndrome caused by co-obstruction of the inferior vena cava and main hepatic veins

BACKGROUND: Collateralized intraand extra-hepatic routes in patients with Budd-Chiari syndrome (BCS) were important. This study aimed to investigate the feasibility and clinical outcomes of the staged management of BCS based on the degree of compensation provided by intraor extra-hepatic collateral circulations. METHODS: A total of 103 adult patients with BCS caused by co-obstruction of the inferior vena cava (IVC) and main hepatic veins (MHVs) between March 2001 and October 2009 were enrolled in this study. Based on the pathological classification and degree of hemodynamic compensation by collateral circulations, treatment priority for IVC hypertension was determined in the first-stage treatment. Patients were deemed eligible for second-stage treatment when the first-stage treatment failed to relieve. RESULTS: Imaging results revealed that most patients had collateral circulations to different extents. Based on the degree of compensation provided by these collateral circulations, 74 patients underwent single-stage treatment for IVC hypertension, i.e., radiologic intervention (RI) for 61 patients and surgical procedures (SPs) for 13. One patient was treated for portal hypertension. Twenty-nine patients underwent second-stage treatment (25 underwent RI and SP, and 4 only SP). The general morbidity and mortality after all procedures were 8.3% and 1.5%, respectively. After a median follow-up of 35 months, 4 patients underwent second-stage treatment and 7 underwent recanalization of the IVC/MHVs. Two patients died of hepatocellular carcinoma and 1 died of graft obstruction. CONCLUSION: Staged management produces excellent outcomes for patients with BCS caused by co-obstruction of the IVC and MHVs.

A New Method for Evaluating Regional Cerebral Blood Flow Changes:Laser Speckle Contrast Imaging in a C57BL/6J Mouse Model of Photothrombotic Ischemia

The present study aimed to improve the processing of data acquired from laser speckle contrast imaging（LSCI） to provide a standardization method to explore changes in regional cerebral blood flow（r CBF） and to determine the correlations among r CBF, cerebral ischemic lesion volume and microvascular density over time in a focal ischemic region. C57BL/6J mice were subjected to focal photothrombotic（PT） ischemia. r CBF was measured using LSCI at different time points before and after PT ischemia through an intact skull. Standardized r CBF（Sr CBF）, defined as the ratio of r CBF measured in the ipsilateral region of interest（ROI） to that in the corresponding contralateral region, was calculated to evaluate potential changes. In addition, the volume of the ischemic lesion and the microvascular density were determined using Nissl staining and immunofluorescence, respectively. The relationships among the ischemic lesion volume, microvascular density and Sr CBF were analyzed over time. The results showed that the cortical r CBF measured using LSCI following PT ischemia in the C57BL/6J mice gradually increased. Changes in the cerebral ischemic lesion volume were negatively correlated with Sr CBF in the ischemic region. Changes in the microvascular density were similar to those observed in Sr CBF. Our findings indicate that LSCI is a practical technique for observing changes in murine cortical r CBF without skull opening and for analyzing the relationships among the ischemic lesion volume, microvascular density and Sr CBF following focal cerebral ischemia. Preliminary results also suggest that the use of LSCI to observe the formation of collateral circulation is feasible.

Renovascular hypertension causes cerebral vascular remodeling

Renovascular hypertensive rats （RHRs） were developed using the 2-kidney, 2-clip method. All RHRs at 10 weeks displayed high permeability of the cerebral surface blood vessels. Vascular casts of the RHRs showed that the vascular network was sparse. The arterioles of the RHRs at 10 weeks had smaller lumen diameters, but thicker vessel walls with hyalinosis formation compared with control animals. The endothelial cell membrane appeared damaged, and microthrombus formed. After ischemia, the infarction size was larger in RHRs than in control animals. These results suggest that cerebral arterioles in RHRs underwent structural remodeling. High blood pressure may aggravate the severity of brain injury in cerebral ischemia and affect the recovery of ischemia.

A Clinical Analysis of the Related Vessels of Acute Inferior Myocardial Infarction

Objective Forty cases of IAMI were examined with coronary angiography in order to study the relationship of the vessels with the ECG of IAMI. Methods For coronary angiography Judkin' s method was used; IAMI was diagnosed by the 1979 WHO's standard of ISHD and ECG was separately measured by two doctors. Results Most of IAMI with polybranch coronary or its collateral disease (32. 5% and 42. 5% ) and only 10 cases (25% ) with single branch coronary disease, whose ECGs were untypical. Conclusion IAMI with single-branch coronary disease might express as mild symptoms and have no typical ECG change. While typical ECG change emerges, the coronary artery always showed poly-branch disease or collateral branch obstruction and the disease would be advanced. It is important to pay more attention to the cases of IAMI without classic ECG change so as to give diagnosis and treatment them in time.

Clinical relevance of angiographic coronary collaterals during primary coronary intervention for acute ST-elevation myocardial infarction

Background Collaterals to occluded infarct-related coronary arteries （IRA） have been observed after the onset of acute ST-elevation myocardial infarction （STEMI）.We sought to investigate the impact of early coronary collateralization,as evidenced by angiography,on myocardial reperfusion and outcomes after primary percutaneous coronary intervention （PCI）.Methods Acute procedural results,ST-segment resolution （STR）,enzymatic infarct size,echocardiographic left ventricular function,and major adverse cardiac events （MACE） at 6-month follow-up were assessed in 389 patients with STEMI undergoing primary PCI for occluded IRA （TIMI flow grade 0 or 1） within 12 hours of symptom-onset.Angiographic coronary collateralization to the occluded IRA at first contrast injection was graded according to the Rentrop scoring system.Results Low （Rentrop score of 0 or 1） and high （Rentrop score of 2 or 3） coronary collateralization was detected in 329 and 60 patients,respectively.Patients with high collateralization more commonly had prior stable angina and right coronary artery occlusion,but less often had left anterior descending artery occlusion.At baseline,these patients presented with less extent of ST-segment elevation and lower serum levels of creatine kinase myocardial band （CK-MB） and cardiac troponin Ⅰ （cTnl）.Procedural success rate,STR,corrected TIMI flame count,and area under the curve of CK-MB and cTnl measurements after the procedure were similar between patients with high collateralization and those with low collateralization （for all comparisons P＞0.05）.There were no differences in left ventricular ejection fraction and rates of MACE at 6 months according to baseline angiographic collaterals to occluded IRA.Conclusions In patients with acute STEMI undergoing primary PCI within 12 hours of symptom-onset,coronary collateralization to the occluded IRA was influenced by clinical and angiographic features.Early recruitment of collaterals limits infarct size at baseline,but has no significant impact on myocardial reperfusion after the procedure and subsequent left ventricular function and clinical outcomes.

Microvessel angiogenesis: a possible cardioprotective mechanism of external counterpulsation for canine myocardial infarction

Background Enhanced external counterpulsation (EECP) has been demonstrated to be effective in the treatment of patients with coronary artery disease (CAD). It has been proposed that the beneficial effects of EECP observed in clinical studies may be due to the formation of new blood vessels (angiogenesis) and collateral development. However, there is a relative paucity of basic studies to support the proposed mechanisms. Methods Twelve Beagle dogs were anesthetized with 3% sodium pentobarbital, 1 mg/kg intraperitoneal injection and mechanically ventilated for the development of myocardial infarction. After coronary occlusion, all animals were randomly assigned to either EECP or control. EECP was given one hour per day, 5 days a week, for a total of 28 to 30 hours treatment over a 6-week course. Immunohistochemical studies of alpha-actin and von Willebrand factor (vWF) were used to detect newly developed microvessels. Systemic and local vascular endothelial growth factor (VEGF) were identified by enzyme linked immunosorbent assay 9(ELISA) and reverse-transcriptional polymerase chain reaction (RT-PCR) analysis. Results There was a significant increase in the density of microvessels per mm(2) in the infarcted regions of EECP group compared to control group (vWF, 15.2 +/- 6.3 versus 4.9 +/- 2.1, P < 0.05; alpha-actin, 11.8 +/- 5.3 versus 3.4 +/- 1.2, P < 0.05), along with significant increase of positive vWF and a-actin stained area. Both immunohistochemical staining and RT-PCR analysis documented a significant increase in VEGF expression. These factors associated with angiogenesis corresponded to improved myocardial perfusion by Tc-99m-sestamibi single-photon emission computed tomography.

Effect and Mechanism of Panaxoside Rg1 on Neovascularization in Myocardial Infarction Rats

Objective：To investigate the effects and mechanisms of panaxoside Rg1 on the new vessel formation in acute myocardial infarction（AMI） rats.Methods：The AMI model of male Sprague-Dawley（SD） rats was established,and rats were randomly divided into the AMI model group,the treatment group of panaxoside Rg1,the placebo group and the treatment group of panaxoside Rg1 plus rapamycin.Cardiac creatases were determined with 1 mL blood drawn from vena caudalis of the rats 48 h after the model was successfully made. After 4 weeks,Evans blue was injected into the aorta roots of the rats,and then,red tetrazoline was dyed again and the myocardial infarction area was evaluated.The microvessel density（MVD） of infarction area was determined by the immunohistochemistry of CD31;enzyme-linked immunosorbent assay（ELISA） was used to detect the protein content of CD31 and hypoxia inducible factor-1α（HIF-1α） of the infarction area. Results：The MVD in the infarction area and the contents of CD31 and HIF-1αin the Rg1 treatment group were higher than those in the AMI model group significantly（P〈0.05）.The cardiac creatase and infarction area were lower in the Rg1 treatment group than those in the AMI model group significantly（P〈0.05）.The above effects,however,disappeared when rapamycin,the antagonist of mammalian target of rapamycin（mTOR）,was administered simultaneously.Conclusions：Panaxoside Rg1 could increase the expression of HIF-1αand CD31 of myocardium and stimulate the angiogenesis.The above mentioned role of panaxoside Rg1 might be related to the excitation of mTOR receptor.