Changes in plasma adenosine concentrations during normal pregnancy

The aim of this study was to measure changes in plasma adenosine concentration [ADO] during a normal pregnancy and to evaluate the possible role of platelets and red blood cells (RBC) as causes of changes in plasma [ADO]. We measured the plasma [ADO] in normal pregnant women (n = 11) during the first, second and third trimesters. The mean plasma [ADO] in the third trimester was 0.41 +/- 0.08 microM (means +/- SEM), significantly higher than in the first and second trimesters (p < 0.05). In pregnant women, platelet and RBC counts, hematocrit and hemoglobin concentration decreased slightly throughout the pregnancy. The elevation in the plasma [ADO] correlated inversely with the platelet count (r = -0.43, p < 0.05). These results suggest that an increase in the plasma [ADO] in the third trimester may be attributed to the enhanced adenosine release from activated platelets.