HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/5/R1465    most recent 00282.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science 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 Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Sandblom, E. Articles by Farrell, A. P. Search for Related Content PubMed PubMed Citation Articles by Sandblom, E. Articles by Farrell, A. P.

COMPARATIVE AND EVOLUTIONARY PHYSIOLOGY

Central venous pressure and mean circulatory filling pressure in the dogfish Squalus acanthias: adrenergic control and role of the pericardium

¹Department of Zoology, Göteborg University, Gothenburg, Sweden; and ²Faculty of Agricultural Sciences and Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada

Submitted 26 April 2006 ; accepted in final form 22 June 2006

Subambient central venous pressure (P_ven) and modulation of venous return through cardiac suction (vis a fronte) characterizes the venous circulation in sharks. Venous capacitance was estimated in the dogfish Squalus acanthias by measuring the mean circulatory filling pressure (MCFP) during transient occlusion of cardiac outflow. We tested the hypothesis that venous return and cardiac preload can be altered additionally through adrenergic changes of venous capacitance. The experiments involved the surgical opening of the pericardium to place a perivascular occluder around the conus arteriosus. Another control group was identically instrumented, but lacked the occluder, and was subjected to the same pharmacological protocol to evaluate how pericardioectomy affected cardiovascular status. Routine P_ven was negative (–0.08 ± 0.02 kPa) in control fish but positive (0.09 ± 0.01 kPa) in the pericardioectomized group. Injections of 5 µg/kg body mass (M_b) of epinephrine and phenylephrine (100 µg/kg M_b) increased P_ven and MCFP, whereas isoproterenol (1 µg/kg M_b) decreased both variables. Thus, constriction and relaxation of the venous vasculature were mediated through the respective stimulation of - and -adrenergic receptors. -Adrenergic blockade with prazosin (1 mg/kg M_b) attenuated the responses to phenylephrine and decreased resting P_ven in pericardioectomized animals. Our results provide convincing evidence for adrenergic control of the venous vasculature in elasmobranchs, although the pericardium is clearly an important component in the modulation of venous function. Thus active changes in venous capacitance have previously been underestimated as an important means of modulating venous return and cardiac performance in this group.

elasmobranch; pulse pressure; venous capacitance

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]

				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]