Plasma adenosine changes during cardiac surgery

Development and application of a LC–MS/MS method to quantify basal adenosine concentration in human plasma from patients undergoing on-pump CABG surgery

“…Due to adenosine's ultrafast turnover in human blood [2], stopping solution was often immediately added into blood sample at collection [3,[30][31][32]. However, even with stopping solution to trap adenosine instantly, Becker et al still could not detect any change of adenosine in coronary sinus or arterial blood (n = 11) after CABG surgery [32].…”

“…Increased plasma adenosine levels in mixed venous blood have also been observed during CABG-CPB surgery [30]. The inverse proportional relationship between oxygen supply and adenosine production [3] might be one of the reasons accounting for the increased coronary C2 and C3 plasma samples were obtained from the coronary sinus 10 min before aorta clamping and 5 min after aorta declamping respectively.…”

“…In the same paper, the half-life of radiolabeled adenosine was about 1.5 s and this fast kinetics has made stopping solution a popular choice when adenosine release needs to be instantly captured to prevent elimination. However, there are three limitations to studying kinetic changes of adenosine: (1) researchers have used variety of cocktails [3,[30][31][32] to inhibit either red blood cell uptake or deaminase degradation of adenosine so that the results are difficult to compare; (2) the ultrafast kinetic change of adenosine makes sampling and timing extremely challenging [30][31][32]; (3) the presence of a short adenosine spike after ischemia condition might not be pharmacologically meaningful. In contrast, determination of the sustained elevation or depression of adenosine basal level by sensitive LC-MS/MS methods may provide consistent results and meaningful insights regarding adenosine steady state, regulation and sustained action on heart.…”