[The role of vitamin E during pregnancy--anti-platelet aggregation activity of alpha-tocopherol].
To clarify the role of vitamin E (alpha-tocopherol) during pregnancy, we mainly investigated the relation between platelet function and vitamin E and obtained the following results. 1. The concentration of vitamin E (alpha-tocopherol) in plasma and platelet increased gradually during pregnancy. The concentration of vitamin E in plasma was 6.65 micrograms/ml in non pregnant women and 15.5 micrograms/ml in full term pregnant women. And the concentration of vitamin E in platelet was 99 micrograms/g protein in non pregnant women and 244 micrograms/g protein in full term pregnant women. 2. Vitamin E (alpha-tocopherol) inhibited platelet aggregation induced by ADP (adenosine diphosphate) and PAF(platelet activating factor). At a concentration of 500 micrograms/ml vitamin E almost completely inhibited platelet aggregation induced by ADP and PAF. 3. There exists a strong platelet aggregation inhibiting activity in human placental brush border membrane vesicles. At a protein concentration of 20 micrograms/ml the brush border membrane vesicles almost completely inhibited platelet aggregation induced by ADP and PAF. 4. With the co-existence of the brush border membrane vesicles, the platelet aggregation inhibiting activity of vitamin E (alpha-tocopherol) increased prominently. These results indicate that vitamin E plays an important role in the regulation of platelet function and might contribute to the maintenance of placental microcirculation by inhibiting platelet aggregation.
Akada
S
S
Department of Obstetrics and Gynecology, Nara Medical University.
Iioka
H
H
Moriyama
I
I
Hisanaga
H
H
Morimoto
K
K
Ichijo
M
M
D000244:Adenosine Diphosphate / Q000037:antagonists & inhibitors; D002824:Chorionic Villi / Q000098:blood supply; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011247:Pregnancy / Q000097:blood*; D014810:Vitamin E / Q000097:blood / Q000502:physiology*
D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D014810:Vitamin E; D000244:Adenosine Diphosphate