Nucleotide ecto-enzyme metabolic pattern and spatial distribution in calcific aortic valve disease; its relation to pathological changes and clinical presentation

Background Extracellular nucleotide metabolism contributes to chronic inflammation, cell differentiation, and tissue mineralization by controlling nucleotide and adenosine concentrations and hence its purinergic effects. This study investigated location-specific changes of extracellular nucleotide metabolism in aortic valves of patients with calcific aortic valve disease (CAVD). Individual ecto-enzymes and adenosine receptors involved were analyzed together with correlation with CAVD severity and risk factors. Results Nucleotide and adenosine degradation rates were adversely modified on the aortic surface of stenotic valve as compared to ventricular side, including decreased ATP removal (1.25 ± 0.35 vs. 2.24 ± 0.61 nmol/min/cm 2 ) and adenosine production (1.32 ± 0.12 vs. 2.49 ± 0.28 nmol/min/cm 2 ) as well as increased adenosine deamination (1.28 ± 0.31 vs. 0.67 ± 0.11 nmol/min/cm 2 ). The rates of nucleotide to adenosine conversions were lower, while adenosine deamination was higher on the aortic sides of stenotic vs. non-stenotic valve. There were no differences in extracellular nucleotide metabolism between aortic and ventricular sides of non-stenotic valves. Furthermore, nucleotide degradation rates, measured on aortic side in CAVD ( n = 62), negatively correlated with echocardiographic and biochemical parameters of disease severity (aortic jet velocity vs. ATP hydrolysis: r = − 0.30, p