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Presents an interactive computer model of rabbit ventricular myocyte ion channels and calcium transport. Development of program to stimulate action potentials; Manipulation by switching voltage and current clamps; Simulation of data from heart failure.

Examines the transduction pathways activated by epinephrine in the toad heart. Role of adrenoreceptors in membrane depolarization and calcium increase; Impact of phospholipase C inhibitor on membrane depolarizations; Differences between responses produced by adrenoreceptor activation and sympathetic nerve stimulation.

Assesses atrial distension, arterial pulsation, and vasopressin release during negative pressure breathing (NB) humans. Effects of postural change on cardiac distension; Modulation of plasma arginine vasopressin by pulse pressure; Impact of posture change on atrial diameter.

Examines the effect of intracellular free magnesium on phosphorylation-dependent modulation of calcium current in the heart. Comparison of magnesium effect after inhibition of protein phosphorylation and after stimulation of cyclic adenosine monophosphate-mediated phosphorylation; Modulation of magnesium activity.

Tests the hypothesis that postexercise replenishment of intramyocellular lipids (IMCL) in enhanced by endurance training and that it is dependent on fat intake. IMCL depletion during exercise; Conclusion that fat intake postexercise strongly promotes IMCL repletion independently of training status.

Examines high-energy phosphates (HEP) and mitochondrial adenosine triphosphatase (mATPase) protein expression in hearts in which myocardial infarction resulted in either compensated ventricular remodeling of congestive heart failure. Effect of oxygen insufficiency on HEP changes in failing hearts; Assessment of myocardial deoxymyoglobin; Mitochondrial protein levels at mATPase subunits.

Studies tricarboxylic acid (TCA) cycle kinetics in the rat heart. Analysis of [sup 13]C (13C) isotopomers; Influence of aminooxyacetate on the kinetics of 13C appearance in glutamate in perfused rat hearts; Potential of metabolic inhibitors in providing novel insights into metabolic transport processes in intact tissues.

Examines the effects of short-term exercise training on the expression of left ventricular (LV) heat shock proteins and contractile performance during in vivo ischemia-reperfusion. Left anterior descending coronary occlusion; Dependence of exercise-associated cardioprotection on increases in myocardial antioxidant defenses.

Examines the influence of endogenous nitric oxide (NO) within the paraventricular nucleus (PVN) of rats on renal sympathetic nerve discharge (RSND) during heart failure (HF). Alteration of the NO system within the PVN involved in controlling autonomic outflow during HF; Effect of the blockade of endogenous NO mechanism on efferent RSND.

Investigates the role of protein kinase C (PKC) beta isoform in cardiac function. Influence of PKC on heart muscle signals affecting contractile function; Alteration in the peak amplitude of calcium transient; Rise in myofilament protein phosphorylation.

Studies the in vivo regulation of the beta-myosin heavy chain gene in hypertensive rodent heart. Mean blood pressure measurements; Plasmid constructs; Site-directed mutagenesis.

Studies the stimulation of cardiac L-type calcium channels by extracellular ATP. Increase in the open probability of cardiac L-type calcium channels with extracellular ATP; Influence of ATP on calcium channel inactivation rate; Relative effects of nucleotides and nucleosides on cardiac L-type calcium channels.

Investigates whether nitric oxide supports right ventricular flow dominance and whole body oxygen utilization in midgestation fetal lambs. Hemodynamics and blood gases; Changes in ventricular outputs; Fetal oxygen content, extraction, delivery, and consumption.

Examines human cardiac myosin heavy chain (MHC) isoforms in fetal and failing adult atria and ventricles. Summary of MHC-alpha composition; Characteristics of failing and nonfailing population; Higher levels of MHC-alpha protein in the left atrium than the ventricles.

Studies cardiomyopathy in transgenic mice with cardiac-specific overexpression of serum response factor (SRF). Generation of SRF transgenic mice; Measurement of the alteration of gene expression of several cardiac genes; Development of cardiomyopathy.

Tests the hypothesis that dichloroacetate improves cardiac efficiency after ischemia independent of changes in mitochondrial proton leak. Measurement of mitochondrial proton leak; Effects of dichloroacetate on oxygen consumption and cardiac efficiency in hearts reperfused following global no-flow ischemia.

Tests the hypothesis that heat pretreatment differentially affects cardiac fatty acid accumulation during ischemia and postischemic reperfusion. Preischemic and reperfusion hemodynamic variables in the hearts of control and heat-shocked rats; Total preischemic and postischemic reperfusion loss of creatine kinase.

Studies heart conduction across the crista terminalis. Activation across the crista terminalis during overdrive pacing of sinus rhythm; Variations in left atrial-to-right atrial activation across the crista terminalis while pacing from thee posterior-inferior left atrium; Activation across the crista terminalis during atrial flutter or atrial fibrillation.

Studies the differential effects of caspase inhibitors on endotoxin-induced myocardial dysfunction and heart apoptosis. Assessment of cardiac function after endotoxin injection; Time-course of caspase activities and nuclear apoptosis in hearts from rats treated with endotoxin.

Examines differential dynamic baroreflex regulation of cardiac and renal sympathetic nerve activities. Power spectra of the intracarotid sinus pressure during the dynamic protocol; Parameters of the neural arc transfer function and step response; Differential high-pass characteristics of neural arc transfer function.

Studies the constructive and destructive addition of forward and reflected arterial pulse waves in the heart. Relationship of arterial load to pulse wave reflection; Determination of whether reflection increases or decreases arterial load; General graphical approach to relate arterial load to reflection.

Tests the hypothesis that targeted disruption of intercellular adhesion molecule (ICAM)-1, and P-selectin genes improve cardiac function and survival in tumor necrosis factor (TNF)-alpha transgenic mice. ICAM-1 and P-selectin mRNA protein expression in hearts of TNF-alpha transgenic mice; Effects of calcium concentration on contractile function of the heart.

Examines the effect of anemia on cardiac function, microvascular structure, and capillary hematocrit in rat hearts. Evidence of angiogenesis in cardiomegaly induced by chronic anemia; Indication that microvascular growth was accompanied by advantageous regulation of red blood cell spacing within these vessels.

Studies the pentose phosphate pathway in isolated rat hearts perfused with [5-[sup3]H]glucose. Contractile performance of perfused heart; Rates of carbo dioxide production during time of perfusion with a given isotopomer of glucose; Glycolytic flux.

Examines changes in uncoupling protein (UCP)-2 and -3 expression in aging rat skeletal muscle, liver, and heart. Effects of aging on skeletal muscle uncoupling protein mRNA and protein levels; Association between aging and tissue-specific alterations of UCP-2 and -3 gene expression in different tissues.

Studies glucose metabolism in perfused mouse hearts overexpressing human GLUT-4 glucose transporter. Measurement of energy substrate metabolism in working heart mode; Functional parameters of cardiac function in perfused working hearts from control and human GLUT-4 mice; Glycogen levels.

Examines the association between myocardial energetics and heat shock response activation in isolated rat heart during cardiac ischemia. Hypothesis on the role of adenosine triphosphate (ATP) in regulating the initiation of heat shock responses; Influence of ATP levels on activation of heat shock factor 1; Hemodynamics of perfused hearts.

Examines the effect of glutathione on the coronary vasomotor reactivity to acetylcholine (ACh) in patients with coronary spastic angina. Stimulation of coronary spasm by ACh; Responses of coronary arteries to nitrate and saline infusion with ACh; Levels of thiobarbituric acid-reactive substances and glutathione peroxidase activity following ACh infusion.

Examines the role of mitochondrial adenosine triphosphate-dependent potassium (mK[sub ATP]) channel as a trigger of cardioprotection against ischemia and reperfusion injury. Mechanism of mK[sub ATP] in mediating cardioprotection; Influence of intracellular calcium and protein kinase C activation on cardioprotection; Role of diazoxide in the cardioprotection process.

Examines the effect of glucocorticoids on the angiotensin-converting enzyme activity of adult cardiac fibroblasts. Influence of dexamethasone on messenger RNA levels; Normalization of stimulatory effect of dexamethasone; Mechanisms involved in glucocorticoid regulation.

Examines the validity and use of volume reduction technique for measuring parallel conductance volume of the heart. Comparison with the saline dilution technique; Effect of ventricular size and contractile state on the volume reduction technique; Repeatability of the two methods.

Examines the role of steroid hormones in the activation of heat-shock factor-1 (HSF-1) in the heart. Activation of HSF-1 by dexamethasone; Interaction of heat-shock proteins (HSP), intracellular hormone receptors, and HSF; Inactivation of HSP by geldanamycin; Rationale for the observed gender differences in cardiovascular diseases.

Investigates the effect of extracellular magnesium on reactive oxygen species (ROS) and calcium accumulation during reoxygenation of cardiomyocytes in rats. Reaction of lactate dehydrogenase to magnesium; Sensitivity of ROS level markers to ROS types; Use of magnesium and 3,4-dichlorobenzamil in counteracting calcium accumulation.

Examines the effect of myocyte oxygenation on myocardial high-energy phosphate (HEP) content during graded coronary hypoperfusion in the intact heart. Relationship of blood flow to myocardial deoxymyoglobin resonance intensity; Influence of blood flow on phosphocreatinine and adenosine triphosphate levels; Correlation of HEP with myoglobin oxygen saturation.

Examines myocardial function in severe right ventricular volume overloading caused by atrial septal resection. Difference between right ventricle (RV) and left ventricle response to volume overloading; Isolation of cardiocytes to assess intrinsic contractile function in myocardium; Toleration of RV volume overloading.

Evaluates the technique used in measuring the activation time of oxidative phosphorylation in isolated mouse hearts. Measurement of the response time of oxygen consumption; Normalized left ventricular pressure measured with a latex balloon positioned in the left ventricle at different pacing.

Studies the influence of nonlinear indexes of some of the variables regulating R-R interval (RRV) variability and systolic blood pressure variability in the rat heart. Effects of different drugs on signal RRV; Decrease in the nonlinearity of RRV with atropine; Physiological changes resulting to the modification of indexes or nonlinear characteristics.

Studies the form of expression, action, second messenger, and the cellular localization of urocortin, a member of the corticotropin-releasing factor family, in the heart. Effect of urocortin on protein synthesis and atrial natriuretic peptide release; Mechanism by which urocortin acts in the heart.

Studies the effects of exercise training on cardiac function, gene expression, and apoptosis in rats. Influence of exercise on body weight and cardiac growth; Increase in stroke volume index at rest in conscious rats with exercise training; Association of the pathological adaptation to pressure overload to the expression of several marker genes.

Examines the effects adenylyl cyclase-mediated coronary vascular responsiveness in stunned myocardium. Coronary reactivity; Tissue flow response to forskolin pre- and post-coronary stenosis; Myocardial oxygen consumption.

Studies the role of nitric oxide in heart ischemic preconditioning. Evaluation of cyclic nucleotides at the end of sustained ischemia; Effects of nitric oxide donors on tissue cyclic nucleotides before onset of sustained ischemia; Influence of ischemic preconditioning and nitric oxide donors on functional recovery after ischemic cardiac arrest.

Studies the functional role of epsilon protein kinase C (PKC) isoenzyme in the regulation of cardiac calcium channels. Sensitivity of L-type calcium channels to dihydropyridines; Phosphorylation of ion channel proteins; Mechanism by which epsilon PKC attenuates the increase in intracellular calcium levels.

Studies the effects of temperature on calcium binding to cardiac troponin C in mammalian and salmonid isoforms. Apparent affinity constants for calcium; Difference in calcium-sensitivity between isoforms; Comparison of amino acid sequences between isoforms.

Investigates whether chronic hypoxia increases the nitric oxide contribution of acetylcholine vasodilation of the fetal guinea pig heart. Cardiovascular responses of fetal guinea pigs to hypoxemia; Basal coronary responses of the fetal guineea pig heart; Increased vessel growth with exposure to chronic hypoxia.

Studies preserved ventricular contractility in infarcted mouse heart overexpressing beta2-adrenergic receptors. Infarct size and grouping of surviving mice; Functional measures by echocardiography and by catheterization in mice; Cardiac functional responses to increasing doses of dobutamine.

Studies the temperature-dependent development of cardiac activity in unrestrained larvae of the minnow Phoxinus phoxinus. Changes in oxygen consumption of minnows at varying temperatures; Diastolic ventricular volume at the onset of cardiac activity and at the time of initial swim bladder inflation in minnow larvae.

Studies the phenotypical features of long Q-T syndrome in transgenic (TGM) mice expressing human sodium-potassium-adenosine triphosphatase alpha[sub3]-isoform in hearts. In vitro evaluation of TGM; Contractility in isolated myocytes; Effect of ouabain concentration on peak positive change in pressure over time in isolated perfused mouse hearts.

Studies the oxygen limitation of thermal tolerance defined by cardiac and ventilatory performance in spider crab, Maja squinado. Variability in hemolymph particle oxygen levels and heart and ventilation rates at control temperature and during temperature decrease or increase; Threshold temperatures in Maja squinado.

Studies the responses of neurons in rostral ventrolateral medulla (RVLM) to activation of cardiac baroreceptors in rats. Responses of RVLM barosensitive and nonbarosensitive neurons to epicardial bradykinin (BK); Effect of blockade of stellate ganglia on response of RVLM barosensitive neurons to BK.

Examines the normal values of regional left ventricular endocardial motion. Average indexes of global left ventricular function; Normal limits of normalized regional ejection and filling time curve; Effect of age on global and regional diastolic performance.