title: Adenosinergic regulation of the cardiovascular system in the red-eared slider Trachemys scripta.
abstract: Few studies have investigated adenosinergic regulation of the cardiovascular system in reptiles. The haemodynamic effect of a bolus intra-arterial adenosine injection (2.5 μM kg⁻¹) was investigated in nine anaesthetised red-eared sliders (Trachemys scripta). Adenosine caused a transient bradycardia, which was accompanied by systemic vasodilatation as evidenced by an increase in systemic flow and a decrease in systemic pressure. Meanwhile, pulmonary flow fell significantly. Both the bradycardia and increase in systemic conductance were significantly attenuated by theophylline (4 mg kg⁻¹), demonstrating an involvement of P₁ receptors. These results suggest that adenosine is likely to play a significant role in reptile cardiovascular physiology. In turtles specifically, adenosinergic regulation may be particularly relevant during periods of apnoea.
authors.affiliation: Zoophysiology, Department of Biosciences, Aarhus University, DK-8000 Aarhus C, Denmark. Electronic address: wimjoyce92@gmail.com.
authors.forename: William
authors.initials: W
authors.lastname: Joyce
authors.affiliation: Zoophysiology, Department of Biosciences, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Tobias
authors.initials: T
authors.lastname: Wang
mesh_terms: D000241:Adenosine / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001919:Bradycardia / Q000139:chemically induced / Q000517:prevention & control / Q000662:veterinary; D002319:Cardiovascular System / Q000187:drug effects / Q000378:metabolism*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D011652:Pulmonary Circulation / Q000187:drug effects; D058915:Purinergic P1 Receptor Antagonists / Q000494:pharmacology; D018047:Receptors, Purinergic P1 / Q000737:chemistry / Q000378:metabolism*; D030162:Reptilian Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013806:Theophylline / Q000494:pharmacology; D014426:Turtles / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology
chemical_list: D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; D030162:Reptilian Proteins; D014665:Vasodilator Agents; D013806:Theophylline; D000241:Adenosine
keywords: Adenosine; Cardiovascular; Reptile; Turtle