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Rijnierse MT, Groeneveldt JA, van Campen JSJA, de Boer K, van der Bruggen CEE, Harms HJ, Raijmakers PG, Lammertsma AA, Knaapen P, Bogaard HJ, Westerhof BE, Vonk Noordegraaf A, Allaart CP, de Man FS. Bisoprolol therapy does not reduce right ventricular sympathetic activity in pulmonary arterial hypertension patients. Pulm Circ 2020; 10:2045894019873548. [PMID: 32363028 PMCID: PMC7187746 DOI: 10.1177/2045894019873548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 07/29/2019] [Indexed: 11/27/2022] Open
Abstract
Right ventricular (RV) function and autonomic dysfunction are important
determinants of morbidity and mortality in patients with pulmonary arterial
hypertension (PAH). Although successful in animal studies, effects of
beta-blocker therapy on RV function in clinical trials were disappointing. To
understand this discrepancy, we studied whether beta-blocker therapy changes RV
sympathetic activity. Idiopathic PAH (IPAH) patients received beta-blocker
therapy (uptitrated to a maximal tolerated dose) and underwent cardiac magnetic
resonance imaging, right heart catheterization, and a
[11C]-hydroxyephedrine positron emission tomography
([11C]HED PET) scan at baseline to determine, respectively, RV
ejection fraction (RVEF), RV pressures, and sympathetic activity.
[11C]HED, a norepinephrine analogue, allows determination of
sympathetic innervation of the RV. [11C]HED retention index reflects
norepinephrine transporter activity. As a consequence of excessive catecholamine
levels in the synaptic cleft, this transporter may be downregulated. Therefore,
low [11C]HED retention index indicates high sympathetic activity. 13
IPAH patients underwent [11C]HED PET scans at baseline and after
bisoprolol treatment. Although heart rate was reduced, systemic modulation of
autonomic activity by bisoprolol did not affect local RV sympathetic nerve
activity, RV function, or RV wall tension. In PAH patients, RV
[11C]HED retention index was lower compared to LV tracer uptake
(p<0.01) and was related to systolic wall tension (R2 = 0.4731,
p<0.01) and RV function (R2 = 0.44, p = 0.01). In RV failure, the
tolerated dosage of bisoprolol did not result in an improvement of RV function
nor in a reduction in RV sympathetic activity.
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Affiliation(s)
- Mischa T Rijnierse
- Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Joanne A Groeneveldt
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Jasmijn S J A van Campen
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Karin de Boer
- Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Cathelijne E E van der Bruggen
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Hendrik J Harms
- Radiology and Nuclear Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Pieter G Raijmakers
- Radiology and Nuclear Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Adriaan A Lammertsma
- Radiology and Nuclear Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Paul Knaapen
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Harm Jan Bogaard
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Berend E Westerhof
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Medical Biology, Section of Systems Physiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Anton Vonk Noordegraaf
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Cornelis P Allaart
- Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Frances S de Man
- Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
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Földes-Papp Z. 'True' single-molecule molecule observations by fluorescence correlation spectroscopy and two-color fluorescence cross-correlation spectroscopy. Exp Mol Pathol 2006; 82:147-55. [PMID: 17258199 DOI: 10.1016/j.yexmp.2006.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Accepted: 12/04/2006] [Indexed: 01/09/2023]
Abstract
Fluorescence correlation spectroscopy (FCS) and two-color fluorescence cross-correlation spectroscopy (FCCS) are a measure of fluctuations of detected light as a fluorescence molecule diffuses through a femtoliter detection volume caused by a tightly focused laser and confocal optics. Fluorescence from a single molecule can easily be distinguished from the slight background associated with a femtoliter of solvent. At a solution concentration of about 1 nM, the probability that there is an analyte molecule in the probe volume is less than one. Although fluorescence from individual molecules is collected, the data are analyzed by autocorrelation or two-color cross-correlation functions that are the average of thousands of molecules. Properties of single molecules are not obtained. I have been working on problems and opportunities associated with very dilute solutions. The molecule in the confocal probe volume is most probably the molecule that just diffused out, turned around, and diffused back in, i.e., reentered. For the first time, some theoretical results of the novel theory of the meaningful time are presented that enable study of just one single molecule over extended periods of times without immobilization or hydrodynamic focusing. Reentries that may also be called reoccurrences or encounters of a single molecule are significant because during measurement times they give rise to fluctuation phenomena such as molecule number fluctuations. Likewise, four criteria have been developed that can be used to verify that there is only one "selfsame" molecule in the laser probe volume during the experiment: (Földes-Papp, Z., 2006. What it means to measure a single molecule in a solution by fluorescence fluctuation spectroscopy. Exp. Mol. Pathol. 80 (3) 209-218).
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Affiliation(s)
- Zeno Földes-Papp
- Medical University of Graz, Department of Internal Medicine, Riesstrasse 58a/5, A-8047 Graz, Austria.
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