Experiments were undertaken to determine whether angiotensin (Ang) II concentration increases during massive sympathetic nervous system (SNS) activation and whether such an increase plays a role in the pathogenesis of SNS-induced left ventricular…
The objective of this study was to determine whether myocardial contractility is depressed by intense activation of the sympathetic nervous system. A massive sympathetic discharge was produced by injecting veratrine or sodium citrate into the…
This study was undertaken to determine if coronary vascular permeability (CVP) increases and if myocardial edema develops in the canine heart after local exposure to histamine. Histamine (50 or 15 micrograms/min) or compound 48/80 (0.1-0.2 mg/kg) was…
BACKGROUND: Intense activation of the sympathetic nervous system or administration of high concentrations of catecholamines diminishes myocardial contractility and produces infarct-like lesions throughout the heart. This study was conducted to…
The present study was undertaken to determine whether the diminished cardiac performance associated with cocaine administration persists after the drug has been eliminated from the body. Cocaine (5 or 10 mg/kg iv) was administered to conscious (n =…
This study was undertaken to determine whether endothelium-derived relaxing factor (EDRF) modulates the pulmonary and systemic hemodynamic responses to massive sympathetic nervous system (SNS) activation and, in so doing, also modulates the degree of…
We evaluated the ability of the canine in situ left lower lobe (LLL) vasculature to sieve endogenous plasma proteins of various molecular radii (34-124 A) after LLL arterial pressure had been transiently elevated to 23.8 +/- 0.9 (control group, n =…
We tested the possibility that neuropeptide Y (NPY) may contribute to the pulmonary hypertension that occurs after massive sympathetic activation produced by intracisternal veratrine administration in the chloralose-anesthetized dog. In six dogs,…
Previous studies have suggested that papaverine, a drug commonly used in studies of transvascular fluid and solute exchange to eliminate confounding effects of changes in vascular tone, may itself increase vascular permeability. In this study, we…
The solvent drag reflection coefficient (sigma) for total proteins can be estimated by comparing the relative degrees of concentration of erythrocytes and plasma proteins that occur during fluid filtration in an isolated perfused organ. In this…
This study was conducted to determine whether increased myocardial energy demand plays a role in norepinephrine (NE)-induced left ventricular (LV) dysfunction. A range of arterial pressure-heart rate (P-R) products (myocardial energy demand) was…
We sought to determine whether catecholamines are responsible for the depressed left ventricular (LV) function that follows massive sympathetic nervous system (SNS) activation and whether the additional myocardial energy demands of
Coronary vascular osmotic reflection coefficients (sigma dS) for total protein, albumin (Alb), immunoglobulin (Ig)G, and IgM were determined in the anesthetized dog. Myocardial lymph was collected from the anterior interventricular lymphatic trunk,…
We evaluated the effect of systemically administered histamine on coronary vascular permeability (CVP) of pentobarbital-anesthetized, open-chest dogs with and without beta-receptor blockade. We determined changes in CVP by comparing prenodal cardiac…