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This Article Full Text Full Text (PDF) All Versions of this Article: 92/3/541    most recent expphysiol.2006.036228v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Alders, D. J. C. Articles by van Beek, J. H. G. M. Search for Related Content PubMed PubMed Citation Articles by Alders, D. J. C. Articles by van Beek, J. H. G. M.

¹ Laboratory for Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands ² Department of Physiology, University of Maastricht, The Netherlands ³ Medicine and Therapeutics, University of Aberdeen, Scotland, UK ⁴ School of Pharmacy, Robert Gordon University, Aberdeen, Scotland, UK ⁵ Departments of Chemistry and Molecular Cell Physiology, Vrije Universiteit, Amsterdam, The Netherlands

Myocardial blood flow and oxygen consumption are heterogeneously distributed. Perfusion and myocardial oxygen consumption are closely correlated in the normal heart. It is unknown how this metabolism–perfusion relation is influenced by sympathetic denervation. We investigated this question in seven chloralose-anaesthetized dogs, 3–4 weeks after regional sympathetic denervation of the left circumflex coronary artery area of supply of the left ventricle. Measurements were made of local myocardial blood flow (MBF, in ml min^–1 (g dry wt)^–1), measured with microspheres, and myocardial oxygen consumption (, in µmol min^–1 (g dry wt)^–1) in the same location, calculated from the ¹³C spectrum of tissue extracts after intracoronary infusion of 3–¹³C-lactate. Since both innervated and denervated regions are subject to the same arterial pressure, lower blood flow indicates higher resistance. Mean MBF was 5.56 ml min^–1 (g dry wt)^–1 (heterogeneity of 3.47 ml min^–1 (g dry wt)^–1) innervated, 7.48 ml min^–1 (g dry wt)^–1 (heterogeneity of 3.62 ml min^–1 (g dry wt)^–1) denervated (n.s.). Significant linear relations were found between MBF and of individual samples within the innervated and denervated regions. The slopes of these relations were not significantly different, but the adjusted mean was significantly higher in the denervated regions (+1.92 ml min^–1 (g dry wt)^–1, an increase of 38% of the mean MBF at the pooled mean , P = 0.028, ANCOVA). The ratio (in ml µmol^–1) was significantly higher, being 0.296 ± 0.167 ml µmol^–1 in the denervated region compared with the innervated region, 0.216 ± 0.126 ml µmol^–1, P = 0.0182, Mann–Whitney U test. These results indicate that sympathetic tone under chloralose anaesthesia imposes a moderate vasoconstrictive effect in the myocardium that is not detected by comparison of the mean blood flow or resistance.

(Received 15 November 2006; accepted after revision 9 February 2007; first published online 15 February 2007)
Corresponding author J. H. G. M. van Beek: Departments of Chemistry and Molecular Cell Physiology, Vrije Universiteit, Amsterdam, The Netherlands. Email: mimnoble{at}abdn.ac.uk