Adenosine and adenosine receptor-mediated action in coronary microcirculation

Abstract

Adenosine is an ubiquitous extracellular signaling molecule and plays a fundamental role in the regulation of coronary microcirculation through activation of adenosine receptors (ARs). Adenosine is regulated by various enzymes and nucleoside transporters for its balance between intra- and extracellular compartments. Adenosine-mediated coronary microvascular tone and reactive hyperemia are through receptors mainly involving A2AR activation on both endothelial and smooth muscle cells, but also involving interaction among other ARs. Activation of ARs further stimulates downstream targets of H2O2, KATP, KV and KCa2+ channels leading to coronary vasodilation. An altered adenosine-ARs signaling in coronary microcirculation has been observed in several cardiovascular diseases including hypertension, diabetes, atherosclerosis and ischemic heart disease. Adenosine as a metabolite and its receptors have been studied for its both therapeutic and diagnostic abilities. The present review summarizes important aspects of adenosine metabolism and AR-mediated actions in the coronary microcirculation.

Correlation Between Retinopathy and Coronary Microcirculation Dysfunction in Patients with Type 2 Diabetes Mellitus

“…19,20 Meanwhile coronary microcirculation is more sensitive to adenosine, which can make coronary microvascular dilation, but the increase of lymphocyte cells could make adenosine expression attenuation, which could generate the dysfunction of coronary microvascular dilation, aggravating CMD. 21,22 Our study reproduced Chen's results and found that the NLR values of patients in DR with A/V nicking group were lower than that in other retinopathy groups (Figure 3.A), and the lymphocyte values were higher than that in other retinopathy groups (Figure 3.B). However, only a small number of patients agreed for further detection of blood samples, and there were few reports on the pathogenesis of eye symptoms of DR with A/V nicking, so we still do not know whether there are differences in blood ketone bodies, fatty acids and other indicators and the role of immune response in patients with DR with A/V nicking.…”

Purinergic interplay between erythrocytes and platelets in diabetes-associated vascular dysfunction

“…ADP can activate P2Y 13 receptors in RBCs to affect cAMP levels leading to inhibition of ATP release [ 24 ]. In addition to vasodilation mediated by adenosine acting on adenosine receptors, adenosine is taken up by RBCs via equilibrative nucleoside transporter 1 (ENT1) for subsequent metabolism [ 1 , 5 , 26 ] (Fig. 1 ).…”

“…Both purinergic P1 and P2 receptors are ubiquitously expressed in endothelial cells and smooth muscle cells in the vasculature [2]. It is increasingly clear that altered vascular purinergic signaling mediated by various nucleotides (e.g., ATP and ADP) and nucleoside (adenosine) significantly contributes to diabetes-associated vascular complications [2][3][4][5].…”

Purinergic Signaling in Oral Tissues

“…However, in the early 1970s, the pioneering studies carried out by Geoffrey Burnstock [ 4 ] pointed out the activity of these compounds as signal molecules. Since then, the influence of purines at extracellular level has been extensively elucidated on a wide variety of physiological and pathological processes in major organ systems including the central and peripheral nervous systems, gastrointestinal, cardiovascular, respiratory, renal, and immune systems [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. However, the role of the purine system in the oral cavity is still not fully elucidated.…”