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Full-Text Articles in Cardiovascular Diseases
Selective Effects Of Intrinsic A2aar Activity On Cardiac And Coronary Injuries With Lps Challenge, Melissa Reichelt, Kevin Ashton, S Mustafa, B Tang, Catherine Ledent, Xing Tan, John Headrick, R Morrison
Selective Effects Of Intrinsic A2aar Activity On Cardiac And Coronary Injuries With Lps Challenge, Melissa Reichelt, Kevin Ashton, S Mustafa, B Tang, Catherine Ledent, Xing Tan, John Headrick, R Morrison
Kevin Ashton
We assessed the impact of A2A adenosine receptor (A2AAR) knockout (KO) on LPS-triggered cardiovascular injuries, inflammation, gene expression and mortality. LPS precipitated cardiac injury, with 7-fold elevations in serum cardiac troponin I (cTnI) and 25–35% reductions in ventricular contractility. Coronary dysfunction was evident as a 20% reduction in reactive hyperaemic flows. A2AAR KO augmented cTnI release 3-fold without modifying ventricular dysfunction. Coronary effects of LPS and A2AAR KO were identical, and LPS no longer modified hyperaemia in A2AAR KO hearts. Effects of A2AAR activity were largely independent of shifts in acute phase reactants (CRP, haptoglobin) and circulating cytokines. Thus, up …
Cardiovascular Adenosine Receptors: Expression, Actions And Interactions, John Headrick, Kevin Ashton, Roselyn Rose'meyer, Jason Peart
Cardiovascular Adenosine Receptors: Expression, Actions And Interactions, John Headrick, Kevin Ashton, Roselyn Rose'meyer, Jason Peart
Kevin Ashton
Intra- and extracellular adenosine levels rise in response to physiological stimuli and with metabolic/energetic perturbations, inflammatory challenge and tissue injury. Extracellular adenosine engages members of the G-protein coupled adenosine receptor (AR) family to mediate generally beneficial acute and adaptive responses within all constituent cells of the heart. In this way the four AR sub-types—A1, A2A, A2B, and A3Rs—regulate myocardial contraction, heart rate and conduction, adrenergic control, coronary vascular tone, cardiac and vascular growth, inflammatory–vascular cell interactions, and cellular stress-resistance, injury and death. The AR sub-types exert both distinct and overlapping effects, and may interact in mediating these cardiovascular responses. The …