Tobias A Bruning

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The "nitric oxide (NO)-pathway" is presumed to be involved in acetylcholine (ACh)- and serotonin (5-hydroxytryptamine, 5-HT)-mediated vasodilatation. In addition, both the 5-HT-induced transient and persistent vasodilator responses in the forearm vascular bed are abolished by the 5-HT3/5-HT4-receptor antagonist ICS 205-930(More)
1. The inhibitory effects of methylene blue (MB) on different types of cholinesterases and [3H]-N-methylscopolamine ([3H]-NMS) binding to muscarinic receptors were studied. 2. Human plasma from young healthy male volunteers, purified human pseudocholinesterase and purified bovine true acetylcholinesterase were incubated with acetylcholine and increasing(More)
A microcomputer (with 8088 or 80286 processor)-based, R-wave triggered system for on-line, semi-continuous measurement of blood flow of one or two limbs, simultaneous with heart rate and eventually intra-arterial blood pressure, is described. The minimal interval between measurements is approximately 4 s, allowing the accurate measurement of maximal flow(More)
In order to study the contribution of the nitric oxide (NO)-pathway to cholinergic vasodilatation in the resistance vessels of the human forearm, we infused acetylcholine (ACh; 0.1 1000 ng/kg/min) or methacholine (MCh; 0.1 A 100 ng/kg/min) in the presence of saline, the NO-scavenger and guanylate cyclase inhibitor methylene blue (MB; 1000 ng/kg/min), or the(More)
The role of muscarinic (M)-receptor subtypes in the regulation of vascular tone has not yet been defined in humans. To analyze the role of M-receptor subtypes in the forearm resistance vasculature of normotensive volunteers (n = 20), we infused acetylcholine (ACh) and methacholine (MCh) in the presence of saline and the antagonists atropine (nonselective),(More)
Attenuated cholinergic vasodilatation has been suggested as an endothelium-related mechanism involved in essential hypertension. We investigated the role of muscarinic (M) receptor subtypes in the forearm resistance vasculature. In eight white men with essential hypertension and eight matched normotensive control subjects (age of both groups, 47 +/- 4(More)
The vascular effects of serotonin (5-hydroxytryptamine, 5-HT) are complex and heterogeneous. In human forearm, we showed that low doses of 5-HT cause marked but transient vasodilatation followed by a persistent vasodilator response. In in vitro and in animal experiments, 5-HT induced release of nitric oxide (NO) through stimulation of endothelial 5-HT1-like(More)
AIMS To compare the effectiveness and safety of a cardiac computed tomography (CT) algorithm with functional testing in patients with symptoms suggestive of coronary artery disease (CAD). METHODS AND RESULTS Between April 2011 and July 2013, 350 patients with stable angina, referred to the outpatient clinic of four Dutch hospitals, were prospectively(More)
Long-term cigarette smoking is the major etiological factor for the development of chronic obstructive pulmonary disease (COPD). Airway inflammation and oxidative stress are implicated in the pathogenesis. Biomarkers reflecting these responses could be analyzed in exhaled breath condensate (EBC). Recently, it became obvious that mediator concentrations in(More)
OBJECTIVE Forearm blood flow plethysmography is a widely accepted in vivo technique for pharmacologic and functional studies in peripheral resistance vessels and veins. Pharmacological effects on forearm blood flow (FBF) are usually expressed by means of dose-response relationships. This approach does not consider the influence of variations in FBF on the(More)