The effect of adrenaline on the temperature dependency of cardiac action potentials in pink salmon <i>Oncorhynchus gorbuscha</i>

Ballesta, Salvador Fontenla; Hanson, Linda M.; Farrell, Anthony P.

doi:10.1111/j.1095-8649.2011.03187.x

Cited by 7 publications

(7 citation statements)

References 36 publications

(42 reference statements)

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“…For example, acute cooling increases the duration of the ventricular action potential [e.g. rainbow trout ( Shiels et al, 2000 ); bluefin tuna ( Galli et al, 2009 ); pink salmon ( Oncorhynchus gorbuscha ) ( Ballesta et al, 2012 )]. This allows more time for Ca 2+ influx during the action potential plateau, possibly on the I Ca window current (see Vornanen, 1998 ), which occurs when L-type Ca 2+ channels that have inactivated reopen during the action potential plateau.…”

Section: Acute Temperature Change and Cardiac Functionmentioning

confidence: 99%

Temperature-induced cardiac remodeling in fish

Keen

Klaiman

Shiels

et al. 2016

Journal of Experimental Biology

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Thermal acclimation causes the heart of some fish species to undergo significant remodelling. This includes changes in electrical activity, energy utilization and structural properties at the gross and molecular level of organization. The purpose of this Review is to summarize the current state of knowledge of temperature-induced structural remodelling in the fish ventricle across different levels of biological organization, and to examine how such changes result in the modification of the functional properties of the heart. The structural remodelling response is thought to be responsible for changes in cardiac stiffness, the Ca2+ sensitivity of force generation and the rate of force generation by the heart. Such changes to both active and passive properties help to compensate for the loss of cardiac function caused by a decrease in physiological temperature. Hence, temperature-induced cardiac remodelling is common in fish that remain active following seasonal decreases in temperature. This Review is organized around the ventricular phases of the cardiac cycle – specifically diastolic filling, isovolumic pressure generation and ejection – so that the consequences of remodelling can be fully described. We also compare the thermal acclimation-associated modifications of the fish ventricle with those seen in the mammalian ventricle in response to cardiac pathologies and exercise. Finally, we consider how the plasticity of the fish heart may be relevant to survival in a climate change context, where seasonal temperature changes could become more extreme and variable.

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Section: Acute Temperature Change and Cardiac Functionmentioning

confidence: 99%

Temperature-induced cardiac remodeling in fish

Keen

Klaiman

Shiels

et al. 2016

Journal of Experimental Biology

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“…Although considerable differences exist in the shape and duration of cardiac APs between fish species, in all cardiac compartments the AP duration (APD) decreases as temperature acutely increases (Vornanen et al, 2002a(Vornanen et al, ,b, 2014Galli et al, 2009;Haverinen and Vornanen, 2009;Ballesta et al, 2012;Shiels et al, 2015). This indicates that inward I Ca and outward K + currents (I K1 , I Kr, I Ks ) are affected differently by temperature at the AP plateau.…”

Section: Acute Temperature Effects On Fish Cardiac Aps and Ion Currentsmentioning

confidence: 99%

“…T wave A wave of an ECG that is generated by ventricular repolarization. (Talo and Tirri, 1991;Vornanen, 1996;Molina et al, 2007;Haverinen and Vornanen, 2009;Galli et al, 2009;Ballesta et al, 2012). This rapid voltage change is produced by the opening of Na + channels, which generate the inward Na + current (I Na ).…”

Section: Threshold Potentialmentioning

confidence: 99%

The temperature dependence of electrical excitability in fish hearts

Vornanen

2016

Journal of Experimental Biology

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Environmental temperature has pervasive effects on the rate of life processes in ectothermic animals. Animal performance is affected by temperature, but there are finite thermal limits for vital body functions, including contraction of the heart. This Review discusses the electrical excitation that initiates and controls the rate and rhythm of fish cardiac contraction and is therefore a central factor in the temperature-dependent modulation of fish cardiac function. The control of cardiac electrical excitability should be sensitive enough to respond to temperature changes but simultaneously robust enough to protect against cardiac arrhythmia; therefore, the thermal resilience and plasticity of electrical excitation are physiological qualities that may affect the ability of fishes to adjust to climate change. Acute changes in temperature alter the frequency of the heartbeat and the duration of atrial and ventricular action potentials (APs). Prolonged exposure to new thermal conditions induces compensatory changes in ion channel expression and function, which usually partially alleviate the direct effects of temperature on cardiac APs and heart rate. The most heat-sensitive molecular components contributing to the electrical excitation of the fish heart seem to be Na + channels, which may set the upper thermal limit for the cardiac excitability by compromising the initiation of the cardiac AP at high temperatures. In cardiac and other excitable cells, the different temperature dependencies of the outward K + current and inward Na + current may compromise electrical excitability at temperature extremes, a hypothesis termed the temperature-dependent depression of electrical excitation.

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“…Lastly, temperature was returned to 148C and recovery was assessed. Experiments were performed in either the absence or presence of a high but physiological dose of AD (500 nM [20,38]). Confocal Ca 2þ imaging and electrophysiological measurements were conducted on separate myocytes, but each underwent the same protocol.…”

Section: (C) Experimental Protocolsmentioning

confidence: 99%

“…The activity of key ion channels and ion pumps involved in excitation-contraction coupling are also modified by AD [17,37] through the b-adrenergic receptor cascade and associated downstream signalling and phosphorylation events. Indeed, AD acting through cAMP-PKA-dependent phosphorylation of proteins has been shown to alter AP duration (APD) in fish heart [38] and to increase D[Ca 2þ ] i through augmentation of both I Ca and SERCA function [39]. Thus, acute temperature change and adrenergic stimulation affect the rate and strength of myocyte contraction and relaxation, which culminates in changes in cardiac output.…”

Section: Introductionmentioning

confidence: 99%

Cardiac function in an endothermic fish: cellular mechanisms for overcoming acute thermal challenges during diving

2015

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Understanding the physiology of vertebrate thermal tolerance is critical for predicting how animals respond to climate change. Pacific bluefin tuna experience a wide range of ambient sea temperatures and occupy the largest geographical niche of all tunas. Their capacity to endure thermal challenge is due in part to enhanced expression and activity of key proteins involved in cardiac excitation-contraction coupling, which improve cardiomyocyte function and whole animal performance during temperature change. To define the cellular mechanisms that enable bluefin tuna hearts to function during acute temperature change, we investigated the performance of freshly isolated ventricular myocytes using confocal microscopy and electrophysiology. We demonstrate that acute cooling and warming (between 8 and 288C) modulates the excitability of the cardiomyocyte by altering the action potential (AP) duration and the amplitude and kinetics of the cellular Ca 2þ transient. We then explored the interactions between temperature, adrenergic stimulation and contraction frequency, and show that when these stressors are combined in a physiologically relevant way, they alter AP characteristics to stabilize excitation-contraction coupling across an acute 208C temperature range. This allows the tuna heart to maintain consistent contraction and relaxation cycles during acute thermal challenges. We hypothesize that this cardiac capacity plays a key role in the bluefin tunas' niche expansion across a broad thermal and geographical range.

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The effect of adrenaline on the temperature dependency of cardiac action potentials in pink salmon Oncorhynchus gorbuscha

Cited by 7 publications

References 36 publications

Temperature-induced cardiac remodeling in fish

Temperature-induced cardiac remodeling in fish

The temperature dependence of electrical excitability in fish hearts

Cardiac function in an endothermic fish: cellular mechanisms for overcoming acute thermal challenges during diving

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