Intracoronary administration of BMC is associated with improved recovery of left ventricular contractile function in patients with acute myocardial infarction. Large-scale studies are warranted to examine the potential effects of progenitor-cell administration on morbidity and mortality.
Background-In stable coronary artery disease (CAD), exercise training has well-documented positive effects on arterial endothelial function. NO derived from endothelial NO synthase (eNOS) is regarded as a protective factor against atherosclerosis. The aim of the present study was to investigate the effects of exercise training on the endothelial function in relation to the expression of eNOS and Akt-dependent eNOS phosphorylation in the left internal mammary artery (LIMA) of patients with stable CAD. Methods and Results-In 17 training patients (T) and 18 control patients (C), endothelium-dependent vasodilation and average peak flow velocity (APV) in response to acetylcholine were measured invasively at study beginning and after 4 weeks in the LIMA. In LIMA tissue sampled during bypass surgery, eNOS expression and content of pospho-eNOSSer 1177 , Akt, and phospho-Akt were determined by Western blot and quantitative reverse transcriptase-polymerase chain reaction. After exercise training, LIMA APV in response to acetylcholine was increased by 56Ϯ8% (from ϩ48Ϯ8% at beginning to ϩ104Ϯ11% after 4 weeks, PϽ0.001). Patients in T had a 2-fold higher eNOS protein expression (T 1.0Ϯ0.7 versus C 0.5Ϯ0.3 arbitrary units, PϽ0.05) and 4-fold higher eNOS Ser 1177 -phosphorylation levels in LIMA-endothelium (1.2Ϯ0.9 versus 0.3Ϯ0.2 arbitrary units, PϽ0.01). A linear correlation was confirmed between Akt phosphorylation and phospho-eNOS levels (Rϭ0.80, PϽ0.05) and between phospho-eNOS and ⌬ APV (Rϭ0.59, PϽ0.05). Conclusions-Exercise training in stable CAD leads to an improved agonist-mediated endothelium-dependent vasodilatory capacity. The change in acetylcholine-induced vasodilatation was closely related to a shear stress-induced/Aktdependent phosphorylation
Exercise training significantly reduced the local expression of TNF-alpha, IL-1-beta, IL-6, and iNOS in the skeletal muscle of CHF patients. These local anti-inflammatory effects of exercise may attenuate the catabolic wasting process associated with the progression of CHF.
Objectives—
The concept of neovascularization in response to tissue ischemia has been extended by the finding of postnatal vasculogenesis initiated by endothelial progenitor cells (EPCs). The aim of this study was to analyze whether a maximal stress test in patients with coronary artery disease (CAD) increases the number of circulating EPCs.
Methods and Results—
Blood concentration of EPCs was analyzed by FACS and cell culture assay in CAD patients with (n=16) or without (n=12) exercise-induced myocardial ischemia and in healthy subjects (n=11) for up to 144 hours after maximal stress test. Plasma concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor, tumor necrosis factor-α, and granulocyte macrophage-colony stimulating factor were determined by ELISA. EPCs increased significantly in ischemic patients, with a maximum after 24 to 48 hours (cell culture: 3.3±0.5-fold increase; FACS: 3.1±0.6-fold increase) and returned to baseline within 72 hour. In nonischemic patients and healthy subjects, no EPC increase was detectable. VEGF levels in ischemic patients increased significantly after 2 to 6 hours (maximum after 2 hours; 4.0±1.1-fold increase) and no change was observed in nonischemic patients and healthy subjects; ΔVEGF and ΔEPC correlated significantly (
r
=0.66).
Conclusions—
Patients with symptomatic CAD respond to a single episode of exercise-induced myocardial ischemia with a time-dependent increase in circulating EPCs. This increase may be related to and preceded by an increase in plasma VEGF.
Intracoronary administration of BMCs is associated with a significant reduction of the occurrence of major adverse cardiovascular events after AMI. Large-scale studies are warranted to confirm the effects of BMC administration on mortality and morbidity in patients with AMIs.
Exercise training improves endothelium-dependent vasodilatation both in epicardial coronary vessels and in resistance vessels in patients with coronary artery disease.
Background-Exercise training (ET) has been shown to improve regional perfusion in ischemic syndromes. This might be partially related to a regeneration of diseased endothelium by circulating progenitor cells (CPCs) or CPC-derived vasculogenesis. The aim of the present study was to determine whether ischemic stimuli during ET are required to promote CPC mobilization in patients with cardiovascular diseases. Methods and Results-Patients with peripheral arterial occlusive disease (PAOD) were randomized to 4 weeks of daily ischemic ET or control (group A). Successfully revascularized patients with PAOD were randomized to 4 weeks of daily nonischemic ET or control (group B). Patients with stable coronary artery disease were subjected to 4 weeks of subischemic ET or control (group C). At baseline and after 4 weeks, the number of KDR ϩ /CD34 ϩ CPCs was determined by fluorescence-activated cell sorting analysis. Levels of vascular endothelial growth factor (VEGF) were measured by ELISA. A Matrigel assay was used to quantify CPC integration into vascular structures. Expression of the homing factor CXCR4 was determined by reverse transcription-polymerase chain reaction. In group A only, ischemic ET increased VEGF levels by 310% (PϽ0.05 versus control) associated with an increase in CPCs by 440% (PϽ0.05 versus control), increased CXCR4 expression, and enhanced integration of CPCs into endothelial networks. In contrast, subischemic ET in groups B and C increased CXCR4 expression and CPC integration. Conclusions-In training programs, symptomatic tissue ischemia seems to be a prerequisite for CPC mobilization.However, ischemic and subischemic ET programs affect CXCR4 expression of CPCs, which might lead to an improved CPC integration into endothelial networks. (Circulation. 2005;111:3391-3399.)
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