ヒト胎盤絨毛上皮の血小板凝集阻止機構

刷子縁膜の血小板凝集阻止活性の妊娠経過による変化

抄録

To investigate the platelet aggregation inhibiting mechanism of human placental chorioepith-elium, we compared the platelet aggregation inhibiting activity of human placental chorioepithelial brush border membrane vesicles (BBMV) and basal plasma membrane vesicles (BPMV) in early, mid and late gestation, and obtained the following results.
(1) Strong platelet aggregation inhibiting activity was found in BBMV of every stage of gestation. BBMV inhibited platelet aggregation induced by ADP (adenosine diphosphate) and arachidonic acid. In contrast, BPMV showed no detectable platelet aggregation inhibiting activity.
(2) We found no difference in the BBMV's inhibiting activity against ADP and arachidonic acid induced platelet aggregation in each stage of gestation.
(3) Quite high ADP degrading activity was present in BBMV of every stage of gestation. The platelet aggregation inducing activity of ADP was quickly lost when ADP was preincubated with BBMV. We found no difference in the BBMV's ADP degrading activity of each stage of gestation.
(4) Platelet thromboxane B₂ production was inhibited by BBMV of each stage of gestation. We found no difference in the BBMV's inhibiting activity against platelet thromboxane B₂ production in each gestational stage.
These results showed that chorioepithelial brush border and basal plasma membrane of the human placenta have markedly different properties with respect to platelet aggregation inhibiting activity. It was indicated that platelet aggregation within the intervillous space of placenta was controlled by the platelet aggregation inhibiting activity of chorioepithelial brush border membrane from early stage of gestation.
[Adv Obstet Gynecol 46 (6) 689-697, 1994 (H6.11)]