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Biomedical subjects

Toshiro Matsunaga

Publications and source records attributed to Toshiro Matsunaga.

At least 19 recordsLinked to original sources
PubMed2006

Increased level of pericardial insulin-like growth factor-1 in patients with left ventricular dysfunction and advanced heart failure.

OBJECTIVES: To test the hypothesis that the cardiac insulin-like growth factor-1 (IGF-1) system is up-regulated in the failing heart, we measured the pericardial (cardiac) and plasma (circulating) IGF-1 levels in coronary artery disease patients. BACKGROUND: Local IGF-1 systems are regulated differently from the systemic IGF-1 system. The cardiac IGF-1 system is up-regulated by the increased left ventricular (LV) wall stress. However, it remains unknown how this system is affected in LV dysfunction and heart failure. METHODS: We measured the plasma and pericardial fluid levels of IGF-1 and brain natriuretic peptide (BNP) in 87 coronary artery disease patients undergoing cardiac surgery, and examined their relationships with LV function and heart failure severity. The expressions of IGF-1 and IGF-1 receptor proteins were examined in endomyocardial biopsies obtained from other patients with normal or impaired LV function. RESULTS: The pericardial IGF-1 and BNP levels were positively correlated with the plasma BNP level (both p < 0.001). The pericardial IGF-1 level was increased in heart failure patients, whereas the plasma IGF-1 level was rather decreased. The pericardial IGF-1 level was inversely correlated with the LV ejection fraction (p < 0.001), whereas the plasma IGF-1 level was not. Positive immunostaining for IGF-1 and IGF-1 receptor proteins was enhanced in myocardial biopsies from failing hearts compared with those from nonfailing hearts. CONCLUSIONS: The pericardial IGF-1 level was increased in patients with LV dysfunction and heart failure, whereas the plasma IGF-1 level was decreased. These results may indicate that up-regulation of the cardiac IGF-1 system serves as a compensatory mechanism for LV dysfunction.

Aged↗
PubMed2006

Feasibility and safety of thrombectomy with TVAC aspiration catheter system for patients with acute myocardial infarction.

Early reperfusion with angioplasty and stenting is established as a central, effective treatment for acute myocardial infarction (AMI). The role of thrombectomy prior to angioplasty remains to be elucidated. To evaluate its feasibility, safety, and efficacy, thrombectomy using a TVAC aspiration catheter system was attempted prior to angioplasty and stenting in 40 consecutive patients with AMI. Fifty consecutive patients with AMI in whom angioplasty and stenting were performed without prior thrombectomy served as controls. Neither distribution of Killip classification nor culprit lesion was different between the two groups. In patients treated with the TVAC system, the procedure was successful in 39/40 patients (98%) and there were no procedure-related complications. In the final coronary angiogram, TIMI-3 (Thrombolysis in Myocardial Infarction) flow was obtained in 37/40 (93%) in patients treated with the TVAC system and 43/50 (86%) in control patients. Electrocardiograms before and after coronary intervention were analyzed in patients with ST elevation AMI (35 patients treated with the TVAC system and 41 control patients). ST elevation recovery >50% of the initial value was observed after coronary intervention in 26/35 (74%) in patients treated with the TVAC system and 26/41 (63%) in control patients (P = 0.33). In the case of anterior AMI, ST elevation recovery >50% of the initial value was observed in 13/17 (76%) in patients treated with the TVAC system and 8/20 (40%) in control patients (P = 0.045). Thus, thrombectomy using a TVAC system is feasible, safe, and may have the potential to enhance ST-segment resolution in patients with anterior AMI.

Aged↗
PubMed2006

Increased pericardial fluid level of matrix metalloproteinase-9 activity in patients with acute myocardial infarction: possible role in the development of cardiac rupture.

BACKGROUND: In an animal model of acute myocardial infarction (AMI), deletion of matrix metalloproteinase (MMP)-9 results in suppression of the development of cardiac rupture. The present study sought to clarify how myocardial MMP-9 activity is related to the pathophysiologies of AMI and cardiac rupture in humans. METHODS AND RESULTS: Levels of interleukin-8 (IL-8), polymorphonuclear leukocyte (PMN) elastase, monocyte chemotactic protein-1 (MCP-1) and MMP activity were measured in the pericardial fluid obtained from 28 patients with angina pectoris (AP group) and 16 patients with AMI (AMI group) undergoing cardiac surgery. In the AMI group, 5 were complicated with ventricular septal perforation (VSP) and the remaining 11 were not (non-VSP). Levels of IL-8, PMN elastase, MMP-2 and MMP-9 activity were all higher in the AMI group than in the AP group. In the AMI group, all levels other than MMP-2 activity were further elevated in cases with VSP compared with those in the non-VSP group. There was no significant difference in MCP-1 among the groups CONCLUSIONS: Markers of neutrophil activation in the infarcted cardiac tissue seem to be elevated in AMI. Highly elevated levels of MMP-9 activity, which may be derived from neutrophils, and PMN elastase may be related to the pathophysiology of VSP or cardiac rupture in AMI.

Acute Disease↗
PubMed2006

Borate cross-linked/total rhamnogalacturonan II ratio in cell walls for the biochemical diagnosis of boron deficiency in hydroponically grown pumpkin.

Boron (B) is an essential micronutrient for vascular plants. The function of B has been demonstrated to cross-link monomeric rhamnogalacturonan II (mRG-II) to form dimeric RG-II-borate (dRG-II-B), and thus to stabilize plant cell walls. The dRG-II-B to total RG-II ratio in the cell walls of pumpkin hydroponically grown under various low-B conditions was analyzed to evaluate its applicability to the diagnosis of plant B deficiency. The dRG-II-B ratio in cell walls ranged between approximately 0.9 in B-sufficient tissues and approximately 0.15 in severe B-deficient tissues, reflecting the B nutritional status of tissues. This result indicates that the degree of B shortage in plant tissues is very likely to be diagnosed by the dRG-II-B ratio in cell walls.

Borates↗
PubMed2006

11B solid-state NMR investigation of the rhamnogalacturonan II-borate complex in plant cell walls.

The boron in plant cell walls, which is water-insoluble and in the solid state, is solubilized by pectinase digestion to give a dimeric rhamnogalacturonan II-borate (dRG-II-B) complex. To clarify the nondestructive structure of boron present in plant cell walls (as represented by sugar beet fiber), we performed 192- and 96-MHz 11B solid state NMR measurements. The use of a high field magnet frequency of 192-MHz enabled us to observe 11B isotropic chemical shifts at -9.7 and -9.6 ppm for dRG-II-B and sugar beet fiber in the solid state, respectively, demonstrating that the boron in isolated dRG-II-B and in plant cell walls is present as a borate-diol ester (1:2). The observation of the magnetic field dependence of the chemical shift and lineshape for the borate-diol ester (1:2) by quadrupolar interaction suggested that the borate complex had a distorted tetrahedral boron structure.

Beta vulgaris↗
PubMed2005

Circulating level of gelatinase activity predicts ventricular remodeling in patients with acute myocardial infarction.

BACKGROUND: Matrix metalloproteinase (MMP) plays an important role in the development of ventricular remodeling in an animal model of acute myocardial infarction (AMI). We examined whether circulating MMP activity can predict left ventricular (LV) remodeling after AMI in humans. METHODS: We measured the circulating level of MMP-2 and MMP-9 activities (gelatinase activity) at 14 days after the onset of AMI by gelatin zymography in 52 consecutive patients (age 62+/-2). All patients underwent direct PTCA and stenting at an acute stage, and were treated subsequently with losartan or enalapril. Biplane left ventriculography was performed at admission, and 2 weeks and 6 months after the onset of AMI. RESULTS: We expressed gelatinolysis activity as the ratio to MMP-2 standard. Mean gelatinase activity was 0.721+/-0.013. We divided patients into two groups, groups with gelatinolysis activity <0.72 (low group, n=27) and >0.72 (high group, n=25). Either change in LV end-diastolic volume index (LVEDVI, ml/m(2)) or end-systolic volume index (LVESVI, ml/m(2)) from admission to 2 weeks was not different between the two groups. Changes in both LVEDVI and LVESVI from 2 weeks to 6 months were greater in high gelatinolysis activity group than those in low activity group. Moreover, circulating level of gelatinolysis activity was positively correlated with changes in LVEDVI and LVESVI from 2 weeks to 6 months. CONCLUSION: These results demonstrate that circulating level of gelatinase activity can predict LV remodeling after AMI. Inhibition of gelatinase activity at the acute phase may be a therapeutic strategy for the prevention of remodeling after AMI.

Biomarkers↗
PubMed2005

C-reactive protein-induced upregulation of extracellular matrix metalloproteinase inducer in macrophages: inhibitory effect of fluvastatin.

OBJECTIVE: Extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP)-9 were reported to be expressed at the macrophage-rich area in human coronary atherosclerotic plaque. We examined whether C-reactive protein (CRP) activates macrophages to express EMMPRIN and MMP-9 in vitro and whether statins inhibit it. METHODS AND RESULTS: Rat peritoneal macrophages were collected by peritoneal lavage, and were incubated in the presence or absence of CRP. CRP at 5 microg/ml increased the gene expression of EMMPRIN relative to GAPDH, measured by RT-PCR, by 1.67+/-0.07 fold at 24 h and by 1.85+/-0.49 fold at 48 h (both p<0.05). The gene expression of MMP-9 in the presence of CRP at 5 microg/ml was followed by 1.36+/-0.11 fold increase at 24 h and by 3.95+/-0.81 fold at 48 h (both p<0.05). CRP at 5 microg/ml for 48 h increased by 6 fold MMP-9 activity, measured by zymography, without affecting tissue inhibitor of metalloproteinases-1. Boiled CRP at 5 mug/ml for 48 h unaffected MMP-9 activity. Fluvastatin blocked the CRP-induced increases in EMMPRIN and MMP-9 expression and activity. Diphenylene iodonium, an inhibitor of NADPH oxidase, had a similar effect on MMP-9 activity. Fluvastatin suppressed the CRP-induced increases in 8-epi-prostaglandin F(2alpha) levels in the condition media. CONCLUSIONS: CRP is an activator for macrophages to enhance EMMPRIN and MMP-9 expression. Fluvastatin inhibits them presumably through its antioxidant effect.

Animals↗
PubMed2005

Enalapril suppresses ventricular remodeling more effectively than losartan in patients with acute myocardial infarction.

BACKGROUND: Ventricular remodeling after acute myocardial infarction (AMI) is associated with increased morbidity and mortality. ELITE II study showed that losartan, an angiotensin receptor blocker, shows a survival benefit to the same degree as captopril, an angiotensin-converting enzyme inhibitor, does in patients with heart failure. However, recent OPTIMAAL study showed that clinical outcomes after losartan are not superior to those after captopril in patients with AMI. We examined the effect of losartan on ventricular remodeling after AMI comparatively with that of enalapril. METHODS: We enrolled 203 consecutive patients with AMI (mean age 62 +/- 11 years). All patients underwent primary percutaneous coronary intervention and were randomly assigned to losartan (25-50 mg, n = 101) or enalapril (2.5-10 mg, n = 102) treatment. Biplane left ventriculography was performed just after primary percutaneous transluminal coronary angioplasty (acute phase) and 6 months after the onset of AMI. RESULTS: Any of the maximal creatine kinase level, left ventricular end-diastolic volume index, end-systolic volume index, and ejection fraction measured at acute phase was not different between losartan and enalapril groups. However, changes in left ventricular end-diastolic index (18 +/- 25 vs 8 +/- 24 mL/m2) and left ventricular end-systolic volume index (10 +/- 20 vs 2 +/- 18 mL/m2) from acute phase to 6 months were significantly greater in losartan than in enalapril group. Change in left ventricular ejection fraction (0.2% +/- 10.3% vs 3.4% +/- 11.6%) from acute phase to 6 months was significantly smaller in losartan than in enalapril group. The plasma level of brain natriuretic peptide at 6 months was significantly higher in losartan than in enalapril group (all P < .05). CONCLUSION: These indicate that enalapril suppresses ventricular remodeling after AMI more effectively than losartan.

Angioplasty, Balloon, Coronary↗
PubMed2005

Angiostatin is negatively associated with coronary collateral growth in patients with coronary artery disease.

Angiostatin, an inhibitor of tumor angiogenesis, is produced by the actions of matrix metalloproteinases (MMP) on plasminogen. Recently, we reported that angiostatin levels are increased in a model of inadequate coronary collateral growth and angiogenesis in response to ischemia, despite high levels of vascular endothelial growth factor (VEGF). We hypothesized that angiostatin levels are negatively associated with collateral formation in patients. Coronary angiograms from 37 patients undergoing coronary bypass surgery were evaluated for the absence of angiographically visible collaterals (Rentrop scores of 0) or the presence of Rentrop classification grade 3 (well developed) collaterals. Pericardial fluid was obtained from each patient during the bypass procedure, and the sample was analyzed for angiostatin, plasminogen, and VEGF (Western analysis) and for combined activities of MMP-2 and MMP-9 (zymographic analysis). In patients with no collaterals, angiostatin level was greater compared with that in patients with well-developed collaterals (3.1 +/- 0.2 vs. 2.3 +/- 0.1 optical density units, P < 0.05). Neither MMP activities nor VEGF levels were different between the two groups of patients. The higher levels of angiostatin in patients with no visible collaterals were reflective of a higher concentration of plasmin/plasminogen (6.2 +/- 0.7 vs. 4.2 +/- 0.5 optical density units, P < 0.05) compared with those in patients with well-developed collateral vessels. Our results support the concept that the growth inhibitor angiostatin may have a negative impact on coronary collateral growth in patients. Perhaps therapies attempting to provoke coronary collateral growth should incorporate approaches to limit or neutralize the effects of growth inhibitors.

Aged↗
PubMed2004

Effects of boron deficiency in cell suspension cultures of Populus alba L.

Cell suspension cultures of Populus alba L. (original cells) require at least 10 microM boron for appropriate growth. Using original cells we established a cell line, T-5B, which can grow in a medium containing low levels of boron (5 microM). The level of boron localized in the cell walls of T-5B cells was one-half that found in the cell walls of original cells maintained in medium containing 100 microM boron, and the level of the rhamnogalacturonan II dimer, cross-linked by a borate ester, also decreased in the former. The sugar composition of whole cell walls of the T-5B cell line was similar that of the original cells, however pectic polysaccharides composed of arabinose or galacturonic acid were easily extracted from T-5B cell walls with 50 mM trans-1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid. Our results suggest that boron deficiency causes a weakening of the interaction among pectic polysaccharides due to a decrease in boron-rhamnogalacturonanII cross-linkage.

Boron↗
PubMed2004

Tumor necrosis factor alpha as an endogenous stimulator for circulating coupling factor 6.

OBJECTIVE: We recently showed that mitochondrial coupling factor 6 (CF6) is present as a pressor substance and a prostacyclin inhibitor in systemic circulation. However, the regulation mechanism for circulating CF6 is unknown. We investigated the role of tumor necrosis factor-alpha (TNF-alpha) in the generation and release of CF6. METHODS AND RESULTS: We used two kinds of cells, human umbilical vein endothelial cells (HUVEC) and ECV-304. The concentration of CF6 in the medium increased with time in both ECV-304 and HUVEC. Treatment of ECV-304 and HUVEC with TNF-alpha enhanced the release of CF6 in a dose-dependent manner concomitantly with the decrease in CF6 content in the mitochondria at 24 h. The released CF6 was characterized to be an active full-length peptide by Western blot. The ratio of CF6 to GAPDH mRNA, measured by real-time polymerase chain reaction, was 1.7 fold increased at 1 h after exposure to TNF-alpha in ECV-304 and HUVEC. This enhanced gene expression and release was blocked or suppressed by 70% by stable transfection of dominant negative mutant I kappa B kinase alpha whose efficacy was confirmed by blockade of translocation of NF-kappa B p65 protein and of degradation of I kappa B alpha protein. Flow cytometry analysis revealed that the cell surface-associated CF6 was significantly increased at 24 h after TNF-alpha in a dose-dependent manner. CONCLUSIONS: TNF-alpha stimulates the gene expression of CF6 via activation of NF-kappa B signaling pathway, and promotes the release of CF6 from ECV-304 and HUVEC.

Blotting, Western↗
PubMed2004

Nicorandil improves cardiac function and clinical outcome in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention: role of inhibitory effect on reactive oxygen species formation.

BACKGROUND: Early reperfusion therapy improves the clinical outcomes of patients with acute myocardial infarction (AMI), but benefits are limited by reperfusion injury in some patients. We examined the effect of nicorandil, a hybrid of K(ATP) channel opener and nicotinamide nitrate, on reactive oxygen species (ROS) formation and clinical outcomes after primary percutaneous coronary intervention (PCI) for AMI. METHODS: Fifty-eight patients with AMI were randomized into control (n = 25) and nicorandil pretreatment groups (n = 33). In the nicorandil group, nicorandil (4 mg as a bolus injection followed by constant infusion at 8 mg/hour for 24 hours) was administered just after admission. ROS formation was assessed by measuring urinary excretion of 8-epi-prostaglandin F2alpha (PGF2alpha) and compared between the 2 groups. Cardiac function and the incidence of reperfusion injury and cardiac events were also compared. RESULTS: Urinary 8-epi-PGF2alpha excretion was increased 2-fold at 60 to 90 minutes after PCI in the control group, whereas it was unchanged after PCI in the nicorandil group (P <.0001 between the 2 groups). The incidence of no-reflow phenomenon was lower in the nicorandil group than in the control group. Left ventricular ejection fraction and cardiac index at 6 months were greater in the nicorandil group than in controls. Plasma brain natriuretic peptide level at 6 months was lower in the nicorandil group. Incidences of inhospital cardiac events and rehospitalization were lower in the nicorandil group than in controls. CONCLUSIONS: Nicorandil improves cardiac function and clinical outcomes in patients with AMI. Suppression of ROS formation may be involved in the mechanism.

Aged↗
PubMed2004

Myocardial angiogenesis.

Coronary angiogenesis and collateral growth are chronic adaptations to myocardial ischemia, which are aimed at restoring coronary blood flow and salvaging myocardium in an ischemic region. Although we have assumed that myriad numbers of growth factors are involving in this adaptation, details in the underlying mechanisms, i.e., number of angiogenic factors, angiostatic factors, their receptors/signaling cascades, interactions/crosstalk among the signaling pathways and receptors, and the time course of expression/function of a particular factor or pathway during the successful adaptation are still unclear; they are, probably, harmonized like a symphony. Although there is as of yet no consensus about the mechanisms and causal factors for these cononary adaptations to ischemia, recent evidence strongly suggests that a balance between growth factors and growth inhibitors is critical. In this review we introduce vascular endothelial growth factor, angiopoietins, and angiostatin, as factors playing pivotal roles in coronary angiogenesis and collateral growth.

Angiopoietins↗
PubMed2004

Characterization of metal binding properties of rhamnogalacturonan II from plant cell walls by size-exclusion HPLC/ICP-MS.

The binding properties of metal ions to a pectic polysaccharide, rhamnogalacturonan II (RG-II), from plant cell walls were analyzed by size-exclusion HPLC/ICP-MS. The dimeric RG-II borate complex (dRG-II-B) from sugar beet and red wine contained 0.8 - 1.1 mol/mol of B, 0.8 - 1.1 mol/mol of Ca, 0.1 - 0.3 mol/mol of Sr, and 0.03 - 0.07 mol/mol of Ba. The treatment of dRG-II-B with Sr2+, Ba2+, Pb2+ or La3+ exchanged the originally present Ca, Sr and Ba. In contrast, monomeric RG-II (mRG-II), which contained approximately 0.1 mol/mol of Ca, formed complexes with La3+, Eu3+, and Lu3+ added to the solution, but did not do so with Ca2+, Sr2+, Ba2+ and Pb2+. The HPLC/ICP-MS and HPLC/RI (refractive index detector) analysis of the partially hydrolyzed mRG-II that was treated with La3+ indicated that the side chains and backbone of mRG-II together form a lanthanoid binding site.

Borates↗
PubMed2003

Occurrence of the primary cell wall polysaccharide rhamnogalacturonan II in pteridophytes, lycophytes, and bryophytes. Implications for the evolution of vascular plants.

Borate ester cross-linking of the cell wall pectic polysaccharide rhamnogalacturonan II (RG-II) is required for the growth and development of angiosperms and gymnosperms. Here, we report that the amounts of borate cross-linked RG-II present in the sporophyte primary walls of members of the most primitive extant vascular plant groups (Lycopsida, Filicopsida, Equisetopsida, and Psilopsida) are comparable with the amounts of RG-II in the primary walls of angiosperms. By contrast, the gametophyte generation of members of the avascular bryophytes (Bryopsida, Hepaticopsida, and Anthocerotopsida) have primary walls that contain small amounts (approximately 1% of the amounts of RG-II present in angiosperm walls) of an RG-II-like polysaccharide. The glycosyl sequence of RG-II is conserved in vascular plants, but these RG-IIs are not identical because the non-reducing L-rhamnosyl residue present on the aceric acid-containing side chain of RG-II of all previously studied plants is replaced by a 3-O-methyl rhamnosyl residue in the RG-IIs isolated from Lycopodium tristachyum, Ceratopteris thalictroides, Platycerium bifurcatum, and Psilotum nudum. Our data indicate that the amount of RG-II incorporated into the walls of plants increased during the evolution of vascular plants from their bryophyte-like ancestors. Thus, the acquisition of a boron-dependent growth habit may be correlated with the ability of vascular plants to maintain upright growth and to form lignified secondary walls. The conserved structures of pteridophyte, lycophyte, and angiosperm RG-IIs suggests that the genes and proteins responsible for the biosynthesis of this polysaccharide appeared early in land plant evolution and that RG-II has a fundamental role in wall structure.

Biological Evolution↗
PubMed2003

Effect of shear stress on asymmetric dimethylarginine release from vascular endothelial cells.

We demonstrated recently that plasma concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthase, are increased by high salt intake concomitantly with a decrease in plasma levels of NO in human hypertension. We investigated the effect of shear stress on ADMA release in 2 types of cells: transformed human umbilical vein endothelial cells (HUVECs; cell line ECV-304) and HUVECs. Exposure of ECV-304 cells and HUVECs to shear stress with the use of a cone-plate viscometer enhanced gene expression of protein arginine methyltransferase (PRMT-1), ADMA synthase. In HUVECs, the ratio of PRMT-1 to glyceraldehyde 3-phosphate dehydrogenase mRNA was increased by 2-fold by a shear stress of > or =15 dyne/cm2. A dominant-negative mutant of IkappaB kinase alpha and troglitazone at 8 micromol/L, an activator of peroxisome proliferator-activated receptor gamma, abolished the shear stress-induced increase in PRMT-1 gene expression in parallel with the blockade of nuclear factor (NF)-kappaB translocation into the nucleus. The activity of dimethylarginine dimethylaminohydrolase, the degradation enzyme of ADMA, was unchanged after shear stress < or =15 dyne/cm2 and was enhanced by 1.48+/-0.06-fold (P<0.05) by shear stress at 25 dyne/cm2. The release of ADMA was increased by 1.64+/-0.10-fold (P<0.05) by shear stress at 15 dyne/cm2 but was not affected by shear stress at 25 dyne/cm2. These results indicate that shear stress enhances gene expression of PRMT-1 and ADMA release via activation of the NF-kappaB pathway. Shear stress at higher magnitudes facilitates the degradation of ADMA, thus returning ADMA release levels to baseline.

Amidohydrolases↗
PubMed2003

Expression of VEGF and angiopoietins-1 and -2 during ischemia-induced coronary angiogenesis.

The mechanisms underlying coronary capillary growth in response to ischemia are undefined. We hypothesized that the expression of vascular endothelial growth factor (VEGF) and angiopoietin (Ang)/Tie-2 were involved in capillary growth as an adaptation to ischemia. To test this hypothesis we measured capillary density, and the expressions of VEGF, Ang-1, Ang-2, and the Tie-2 receptor and its phosphorylation state during repetitive episodes of myocardial ischemia in chronically instrumented canines. Repetitive episodes of ischemia were induced by multiple (once/hour; 8/day), brief (2 min) occlusions of the left anterior descending coronary artery for 1, 7, 14, or 21 days. A sham group received the same instrumentation as the experimental groups but not the occlusion protocol. Collateral blood flow (microspheres) progressively increased from 9 +/- 3 to 83 +/- 10 ml. min-1. 100 g-1 on day 21. Capillary density increased at day 7 from 2378 +/- 53 (sham) to 2962 +/- 60/mm2, but it decreased to 2594 +/- 39/mm2 at day 21. Both VEGF and Ang-2 expression in myocardial interstitial fluid (Western analyses) peaked at day 3 of the repetitive occlusions but waned thereafter. In contrast the expression of Ang-1 remained relatively constant at all times in the occlusion groups. In shams, the expression of VEGF and Ang-2 was low and constant at all times. Tie-2 phosphorylation myocardial decreased decreased at day 7 but increased at 21 days of occlusions (P < 0.05). Our results indicate that capillary density was augmented by myocardial ischemia, but after development of collaterals and restoration of flow to the ischemic zone, capillary density returned to control levels. The change in capillary density paralleled with VEGF and Ang-2 expression but was inversely related to Tie-2 phosphorylation. We speculate the coronary angiogenesis is a coordinated event involving the expression of both VEGF and Ang-2 and that therapeutic angiogenic strategies may ultimately require treatment with more than a single factor.

Angiogenesis Inducing Agents↗