Adrenergic and adenosinergic regulation of the cardiovascular system in the Antarctic icefish Chaenocephalus aceratus
Data DOI:
https://doi.org/10.15784/601409
Cite as
O'Brien, K., Axelsson, M., Egginton, S., Farrell, A., & Joyce, M. (2020) "Adrenergic and adenosinergic regulation of the cardiovascular system in the Antarctic icefish Chaenocephalus aceratus" U.S. Antarctic Program (USAP) Data Center. doi: https://doi.org/10.15784/601409.
AMD - DIF Record(s)
USAP-1341602_1
Abstract
Icefishes characteristically lack the oxygen-binding protein haemoglobin and therefore are especially reliant on cardiovascular regulation to augment oxygen transport when oxygen demand increases, such as during activity and warming. Using both in vivo and in vitro experiments, we evaluated the roles for adrenaline and adenosine, two well-established cardio- and vasoactive molecules, in regulating the cardiovascular system of the blackfin icefish, Chaenocephalus aceratus. Despite increasing cardiac contractility (increasing twitch force and contraction kinetics in isometric myocardial strip preparations) and accelerating heart rate (ƒH), adrenaline (5 nmol kg-1 bolus intra-arterial injection) did not significantly increase cardiac output (Q̇) in vivo because it elicited a large decrease in vascular conductance (Gsys). In contrast, and despite preliminary data suggesting a direct negative inotropic effect of adenosine on isolated atria and little effect on isolated ventricle strips, adenosine (500 nmol kg-1) generated a large increase in Q̇ by increasing Gsys, a change reminiscent of that previously reported during both acute warming and invoked activity. Our data thus illustrate how Q̇ in C. aceratus may be much more dependent on peripheral control of vasomotor tone than direct regulation of the heart.
Creator(s):
O'Brien, Kristin;
Joyce, Michael;
Axelsson, Michael;
Farrell, Anthony;
Egginton, Stuart
Date Created:
2020-12-18
Repository:
USAP-DC (current)
Temporal Extent(s)
Start: 2014-09-01 - End: 2019-08-31
Award(s)
Version:
1
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This dataset has been downloaded 2 times since March 2017 (based on unique date-IP combinations)