An ADPase-like substance in placental extracts.
The inhibitory effect of human placenta on ADP-induced platelet aggregation was examined. Placental extracts were purified by chromatography and gel filtration. The eluted fractions were subjected to affinity chromatography with Bestatin AH-Sepharose to obtain a more purified substance. A substance markedly inhibited platelet aggregation induced by ADP, and also exhibited high placental leucine aminopeptidase (P-LAP) activity. Preincubation of sample with ADP abolished the platelet aggregatory effect. Thin-layer chromatography (TLC) analysis revealed that the substance hydrolyzed ADP to AMP. The potent anti-platelet aggregating activity of placental extracts appears to be due to ADPase-like action. This action may be one of the controlling factors of hemostasis in fetoplacental circulation.
Matsumoto
T
T
Department of Obstetrics and Gynecology, National Tsu Hospital, Mie, Japan.
Sugiyama
Y
Y
Deguchi
K
K
Okano
K
K
D000244:Adenosine Diphosphate / Q000502:physiology*; D000469:Alkaline Phosphatase / Q000494:pharmacology; D001081:Apyrase / Q000494:pharmacology*; D001798:Blood Proteins / Q000494:pharmacology; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D066298:In Vitro Techniques; D007931:Leucyl Aminopeptidase / Q000494:pharmacology; D009113:Muramidase / Q000494:pharmacology; D010924:Placental Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors
D001798:Blood Proteins; D010924:Placental Extracts; D010975:Platelet Aggregation Inhibitors; C031220:urokinase inhibitor; D000244:Adenosine Diphosphate; D000469:Alkaline Phosphatase; D009113:Muramidase; D007931:Leucyl Aminopeptidase; D014568:Urokinase-Type Plasminogen Activator; D001081:Apyrase