The role of adrenaline as a modulator of cardiac performance in two Antarctic fishes

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

“…Therefore, frequency effects on APD tend to offset AD effects in ventricular tissue, an interaction that was not resolved in the present study. In addition, AD reduced the length of myocardial contraction in Atlantic salmon Salmo salar L. 1758 (Vierimaa et al , 2006), but a chronotropic effect of AD was absent and an inotropic effect was small for sea bass Dicentrarchus labrax (L. 1758) (Farrell et al , 2007) and two icefish species Chaenocephalus aceratus (Lönnberg 1906) and Notothenia coriiceps Richardson 1844 (Skov et al , 2008). Thus, the wide diversity of cardiac adrenergic response among fishes suggests that it may be an important target for natural selection, especially with respect to temperature challenges.…”

“…AD has variable cardiac effects among fish species, but Skov et al (2008) previously suggested that AD can increase the strength of cardiac contraction without increasing the contraction duration. Here, this was not the case, with AD lengthening ventricular APD.…”

Cold-induced changes in stress hormone and steroidogenic transcript levels in cunner (Tautogolabrus adspersus), a fish capable of metabolic depression

“…This reduced adrenergic humoral response has largely been attributed to the pre-dominance of cholinergic over adrenergic control of the cardiovascular system (Davison et al, 1997;Egginton and Davison, 1998;Nilsson et al, 1996). However, recent research (Skov et al, 2009) shows that while adrenaline is not an important mediator of heart rate in Antarctic fishes, it significantly enhances myocardial contractile force. This data argues against the hypothesis that poststress catecholamine levels are low in cold-water adapted species because they are not important in cardiovascular regulation.…”

Adrenergic and adenosinergic regulation of the cardiovascular system in an Antarctic icefish: Insight into central and peripheral determinants of cardiac output

“…Nevertheless, in in situ perfused hearts, maximum adrenergic stimulation had little or no effect on maximum Q VS or fH in icefish (C. aceratus and Chionodraco rastrospinosus) (Egginton et al, submitted). Skov et al (2009) revealed a positive inotropic effect of adrenaline in C. aceratus, in isometric ventricular strip preparations, while atrial preparations were insensitive to adrenaline (Skov et al, 2009).…”

“…The role of catecholamines in the regulation of the cardiovascular system in notothenioids, including icefishes, has proven controversial (Egginton, 1997;Skov et al, 2009;Whiteley and Egginton, 1999), in part because plasma catecholamine levels are normally unchanged during the stress associated with exercise (Egginton, 1997), unlike the more typical teleostean response (Reid et al, 1998). Nevertheless, plasma catecholamines can increase under extreme conditions, such as following capture by trawling (Whiteley and Egginton, 1999).…”