A5008223259- Nitric Oxide and Endothelin Effects
- Cardiac Imaging and Diagnostics
- Cardiac Ischemia and Reperfusion
- Cardiovascular Function and Risk Factors
- Cardiac electrophysiology and arrhythmias
- Mitochondrial Function and Pathology
- Angiogenesis and VEGF in Cancer
- Heart Rate Variability and Autonomic Control
- Coronary Interventions and Diagnostics
- Cardiovascular Disease and Adiposity
- Cardiac Fibrosis and Remodeling
- Adipose Tissue and Metabolism
- Ion channel regulation and function
- Eicosanoids and Hypertension Pharmacology
- Receptor Mechanisms and Signaling
- Cardiomyopathy and Myosin Studies
- Ion Channels and Receptors
- Tissue Engineering and Regenerative Medicine
- MicroRNA in disease regulation
- Atherosclerosis and Cardiovascular Diseases
- Acute Myocardial Infarction Research
- Cardiac and Coronary Surgery Techniques
- Renin-Angiotensin System Studies
- Circular RNAs in diseases
- Extracellular vesicles in disease
Northeast Ohio Medical University
2016-2025
Ohio University
2006-2020
Kent State University
2015-2018
Medical College of Wisconsin
1998-2017
Versiti Blood Center of Wisconsin
2017
Doernbecher Children's Hospital
2017
La Jolla Institute for Immunology
2017
University of California, San Diego
2017
Oregon National Primate Research Center
2017
Oregon Health & Science University
2015
Assessment of coronary blood flow and the vasodilator reserve capacity individual arteries in catheterization laboratory has been hampered by methodologic limitations. We have developed validated a small Doppler catheter that can subselectively measure phasic velocity (CBFV). In seven anesthetized calves, CBFV was varied from 0.1 to 5.7 times control CBFV. Changes mean measured intraluminally left anterior descending circumflex were similar those simultaneously with an epicardial probe on...
Flow-mediated dilation has been documented in large conduit coronary arteries but not arterioles. The goal of this study was to determine whether response occurs arterioles and it competes with myogenic constriction. Subepicardial (40-80 microns) were isolated cannulated two glass micropipettes connected independent reservoir systems. During zero flow, responses studied over the range intraluminal pressure (IP) between 20 140 cmH2O. Myogenic constrictions dilations observed when IP increased...
Pressure-induced myogenic responses and flow-induced vasodilatory have been documented in coronary resistance arterioles, but the interaction of these two mechanisms nature flow-mediated response are not well understood. Experiments were designed to quantitatively study pressure- characterize substance responsible for dilation isolated arterioles. Subepicardial arterioles (40-80 microns) from pigs cannulated with glass micropipettes then pressurized via independent reservoir systems. Flow...
To determine the distribution of resistance in coronary vasculature, measurements microvascular pressure and diameter were obtained with vasomotor tone intact during dilation produced by papaverine. We studied anesthetized, open-chest cats used jet ventilation synchronized to cardiac cycle eliminate respiratory-induced motion. The system for measuring compensated motion stroboscopic illumination microvessels a computer-controlled electromechanical micromanipulator that moved micropipette...
Inflammation is a condition that underscores many cardiovascular pathologies including endothelial dysfunction, but no link yet established between the vascular pathology of metabolic syndrome with particular inflammatory cytokine. We hypothesized impairments in coronary function obese prediabetic caused by TNF-α overexpression. To test this, we measured endothelium-dependent (acetylcholine) and -independent vasodilation (sodium nitroprusside) isolated, pressurized small arteries from lean...
Abstract Background and aims Takotsubo syndrome (TTS) is a conundrum without consensus about the cause. In murine model of coronary microvascular dysfunction (CMD), abnormalities in myocardial perfusion played key role development TTS. Methods results Vascular Kv1.5 channels connect blood flow to metabolism their deletion mimics phenotype CMD. To determine if TTS related CMD, wild-type (WT), Kv1.5−/−, TgKv1.5−/− (Kv1.5−/− with smooth muscle-specific expression channels) mice were studied...
Background Coronary microvessels (<300 μm in diameter) have been demonstrated to be important the regulation of local resistance and flow. Recent studies also suggest that these are more responsive physiological pharmacological stimuli than conduit vessels. However, little is known regarding relative sensitivity different microvascular segments response flow (shear stress) agonists. The goal this study was test hypothesis a longitudinal gradient for shear stress– agonist-induced dilation...
We hypothesized that ischemia-induced expression of vascular endothelial growth factor (VEGF) and the production NO stimulate coronary collateral growth.To test this hypothesis, we measured blood flow VEGF in myocardial interstitial fluid a canine model repetitive ischemia under control conditions during antagonism synthase. Collateralization was induced by multiple (1/h; 8/d), brief (2 minutes) occlusions left anterior descending artery for 21 days. In controls, (microspheres) progressively...
Background— We hypothesized that the inflammatory cytokine tumor necrosis factor-α (TNF) produces endothelial dysfunction in type 2 diabetes. Methods and Results— In m Lepr db control mice, sodium nitroprusside acetylcholine induced dose-dependent vasodilation, dilation to was blocked by NO synthase inhibitor N G -monomethyl- l -arginine. diabetic (Lepr ) acetylcholine- or flow-induced blunted compared with , but produced comparable dilation. mice null for TNF (db − /db ), flow greater than...
The goals of this study were 1) to quantitate the effects atherosclerosis on physiological and pharmacological endothelium-dependent vasoactive responses in coronary arterioles downstream from arterial lesions 2) determine if administration L-arginine, precursor for endothelium-derived was induced pigs, vasomotor isolated, cannulated (30-70 microns diameter) assessed by measuring diameter changes vitro. To assess alterations responses, dose-response curves constructed ADP, serotonin,...
The purpose of this study was to investigate if myogenic responses isolated coronary arterioles were dependent on an intact, functional endothelium. Arterioles located in situ by intracoronary perfusion with india ink-gelatin solution and then dissected cannulated at both ends glass micropipettes. Intraluminal pressure initially set 60 cm H2O; the altered steps 20 H2O over a range 20-140 H2O. developed spontaneous tone exhibited significant response physiological saline (36 degrees -37 C)....
The goal of this study was to examine myogenic responses isolated porcine subepicardial and subendocardial arterioles (80–100 micron in diameter) within physiological ranges intraluminal pressure. Arterioles were located by perfusion with india ink-gelatin solution then dissected cannulated glass micropipettes. Intraluminal pressure altered 20-cmH2O steps over the range 20–140 cmH2O. IN salt (36–37 degrees C), coronary developed spontaneous tone exhibited responses. At lower pressures (20–60...
This study assessed the redistribution of coronary microvascular resistance during vasodilation produced by dipyridamole. Measurements diameter and pressure in beating left ventricle anesthetized cats were accomplished means a computer-controlled system that enabled measurements heart. Resistances arteries, microvessels, veins calculated from quotients gradient across each vascular compartment myocardial perfusion (radioactive microspheres). Administration dipyridamole increased blood flow...
We tested the hypothesis that nitric oxide (NO) inhibits endothelium-derived hyperpolarizing factor (EDHF)-induced vasodilation via a negative feedback pathway in coronary microcirculation. Coronary microvascular diameters were measured using stroboscopic fluorescence microangiography. Bradykinin (BK)-induced dilation was mediated by EDHF, when NO and prostaglandin syntheses inhibited, or EDHF blocked. Specifically, BK (20, 50, 100 ng. kg(-1). min(-1) ic) caused dose-dependent similarly...
Knowledge concerning phasic coronary blood flow is based primarily on measurements obtained from epicardial arteries, which, in part, function as capacitors. If present, capacitance effects could obscure the dynamic nature of intramyocardial perfusion. To analyze this effect capacitance, we simultaneously measured velocity an artery (left anterior descending) and intramural (septal) open-chest, anesthetized dogs. During control conditions, percentage total occurring during diastole per...