Plasma adenosine levels increase in women with normal pregnancies.
OBJECTIVE
The aim of this study was to investigate plasma adenosine levels during normal pregnancy and to evaluate the possible roles of platelet activation and 5'-nucleotidase as causes of changes in adenosine levels.


METHODS
We measured plasma adenosine levels, the platelet activation markers beta-thromboglobulin and platelet factor 4, and 5'-nucleotidase activity, which catalyzes dephosphorylation from adenosine monophosphate to adenosine, in 34 nonpregnant women and 34 women with normal pregnancies in the third trimester.


RESULTS
The mean plasma adenosine level in pregnant women was 0.59 +/- 0.08 micromol/L (mean +/- SEM), which was significantly higher than that found in nonpregnant women (0.18 +/- 0.04 micromol/L; P <.01). In pregnant women plasma beta-thromboglobulin levels, platelet factor 4 levels, and 5'-nucleotidase activity were significantly higher than in nonpregnant women (P <.05).


CONCLUSIONS
The increase of plasma adenosine may be attributed at least in part to platelet activation and an increase of 5'-nucleotidase activity during normal pregnancy. This increase may be an endogenous compensatory mechanism that diminishes platelet activation and maintains vessel integrity during normal pregnancy.
Yoneyama
Y
Y
Department of Obstetrics and Gynecology, Nippon Medical School, Japan.
Suzuki
S
S
Sawa
R
R
Otsubo
Y
Y
Power
G G
GG
Araki
T
T
D015720:5'-Nucleotidase / Q000097:blood; D000241:Adenosine / Q000097:blood*; D000328:Adult; D005260:Female; D006801:Humans; D010978:Platelet Factor 4 / Q000032:analysis; D011247:Pregnancy / Q000097:blood*; D012016:Reference Values; D001620:beta-Thromboglobulin / Q000032:analysis
D001620:beta-Thromboglobulin; D010978:Platelet Factor 4; D015720:5'-Nucleotidase; D000241:Adenosine