QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online December 10, 2003
Journal of Experimental Biology 207, 195-201 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.00742

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Altimiras, J. Articles by Axelsson, M. Search for Related Content PubMed PubMed Citation Articles by Altimiras, J. Articles by Axelsson, M. Social Bookmarking                         What's this?

Intrinsic autoregulation of cardiac output in rainbow trout (Oncorhynchus mykiss) at different heart rates

Jordi Altimiras^* and Michael Axelsson

Department of Zoology, University of Göteborg, Box 463, S-405 30 Göteborg, Sweden

^* Author for correspondence at present address: Department of Biology, IFM, Linköpings Universitet, SE-58183 Linköping, Sweden (e-mail: jordi{at}ifm.liu.se)

Accepted 3 October 2003

Intrinsic regulation of the heart in teleosts is partly driven by central venous pressure, which exerts a modulatory role on stroke volume according to the well-known Frank-Starling mechanism. Although this mechanism is well understood from heart perfusion studies, less is known about how this mechanism operates in vivo, where heart rate varies markedly. We used zatebradine, a bradycardic agent, to attain resting heart rates in surgically instrumented animals. A dose of zatebradine of 2.79±0.47 mg l^-1 decreased heart rate by half, from 44.4±4.19 beats min^-1 to 22.1±1.9 beats min^-1. Zatebradine had no significant effect on the peripheral vasculature and no inotropic effects, so was a suitable pharmacological agent with which to manipulate heart rate. When heart rate halved, cardiac output dropped to 87.5±4.6% of the control value, due to the concomitant increase in stroke volume to 165±13%. In vivo recordings of venous pressure at varying heart rates indicated that the partial compensation in cardiac output was possible through an increase in pressure in the sinus venosus, from -0.06±0.04 kPa at a control heart rate of 58.3±3.5 beats min^-1 (N=10) to 0.07±0.05 kPa after injection of zatebradine (4 mg kg^-1). The operation of the so-called time-dependent autoregulatory mechanism was further demonstrated in perfused hearts. The positive pressures recorded in the sinus venosus at low heart rates coincident with non-invasive measurements in trout suggest that atrial filling in trout is more dependent on the build-up of pressure in the venous circulation (vis-à-tergo filling) than a suction mechanism during ventricular contraction (vis-à-fronte filling).

Key words: venous pressure, heart rate, Frank-Starling mechanism, zatebradine, rainbow trout, fish, Oncorhynchus mykiss

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

Related articles in JEB:

TROUT HEARTS DON'T ALWAYS SUCK

Kathryn Phillips
JEB 2004 207: 189-190. [Full Text]  

This article has been cited by other articles:

				E. Sandblom, G. K. Cox, S. F. Perry, and A. P. Farrell The role of venous capacitance, circulating catecholamines, and heart rate in the hemodynamic response to increased temperature and hypoxia in the dogfish Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2009; 296(5): R1547 - R1556. [Abstract] [Full Text] [PDF]

				T. D. Clark, E. Sandblom, G. K. Cox, S. G. Hinch, and A. P. Farrell Circulatory limits to oxygen supply during an acute temperature increase in the Chinook salmon (Oncorhynchus tshawytscha) Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2008; 295(5): R1631 - R1639. [Abstract] [Full Text] [PDF]

				E. Sandblom and M. Axelsson Venous hemodynamic responses to acute temperature increase in the rainbow trout (Oncorhynchus mykiss) Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2007; 292(6): R2292 - R2298. [Abstract] [Full Text] [PDF]

				E. Sandblom, M. Axelsson, and A. P. Farrell Central venous pressure and mean circulatory filling pressure in the dogfish Squalus acanthias: adrenergic control and role of the pericardium Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2006; 291(5): R1465 - R1473. [Abstract] [Full Text] [PDF]

				M. Skals, N. Skovgaard, E. W. Taylor, C. A. C. Leite, A. S. Abe, and T. Wang Cardiovascular changes under normoxic and hypoxic conditions in the air-breathing teleost Synbranchus marmoratus: importance of the venous system J. Exp. Biol., October 15, 2006; 209(20): 4167 - 4173. [Abstract] [Full Text] [PDF]

				E. Sandblom and M. Axelsson Adrenergic control of venous capacitance during moderate hypoxia in the rainbow trout (Oncorhynchus mykiss): role of neural and circulating catecholamines Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2006; 291(3): R711 - R718. [Abstract] [Full Text] [PDF]

				E. Sandblom, A. P. Farrell, J. Altimiras, M. Axelsson, and G. Claireaux Cardiac preload and venous return in swimming sea bass (Dicentrarchus labrax L.) J. Exp. Biol., May 15, 2005; 208(10): 1927 - 1935. [Abstract] [Full Text] [PDF]

				E. Sandblom and M. Axelsson Baroreflex mediated control of heart rate and vascular capacitance in trout J. Exp. Biol., March 1, 2005; 208(5): 821 - 829. [Abstract] [Full Text] [PDF]

				K. Phillips TROUT HEARTS DON'T ALWAYS SUCK J. Exp. Biol., January 15, 2004; 207(2): 189 - 190. [Full Text] [PDF]