Cardiac influence of the {beta}3-adrenoceptor in the goldfish (Carassius auratus): a protective role under hypoxia? [RESEARCH ARTICLE]

Serena Leo, Alfonsina Gattuso, Rosa Mazza, Mariacristina Filice, Maria Carmela Cerra, and Sandra Imbrogno The goldfish (Carassius auratus) exhibits a remarkable capacity to survive and remain active under prolonged and severe hypoxia, representing a well-suited model to study cardiac function when oxygen availability represents a limiting factor. Under hypoxia, the goldfish heart increases its performance, this representing a putative component of hypoxia tolerance; however, underlying mechanisms have not been yet elucidated. We aimed to investigate the role of β3-ARs in the mechanisms which modulate the goldfish heart performance, also in relation to oxygen levels. By western blotting analysis, we found that the goldfish heart expresses β3-ARs, and this expression increases under hypoxia. Effects of β3-ARs stimulation were analysed by using an ex vivo working heart preparation. Under normoxia, the β3-ARs selective agonist BRL37344 (10–12-10–7M) elicited a concentration-dependent increase of contractility abolished by the specific β3-AR antagonist (SR59230A; 10–8M), but not by α/β1/β2-ARs inhibitors (phentolamine, nadolol, and ICI118,551; 10–7M). Under acute hypoxia, BRL37344 did not affect the goldfish heart performance. However, SR59230A, but not phentolamine, nadolol, and ICI118,551, abolished the time-dependent enhancement of contractility which characterizes the hypoxic goldfish heart. Under both normoxia a...

Source: Journal of Experimental Biology - September 15, 2019 Category: Biology Authors: Leo, S., Gattuso, A., Mazza, R., Filice, M., Cerra, M. C., Imbrogno, S. Tags: RESEARCH ARTICLE Source Type: research