抄録
In our series of study on DIC, we found coincidentally that plasma prekallikrein determined chromogenic tripeptide substrate (S-2302) changed with close relation to labor and sexual cycle. In order to confirm the possible role of prekallikrein in the reproduction physiology, the animal experiment was performed. The results obtained were as follows:
(1) Plasma prekallikrein was increased during pregnancy with advance of gestational ages, and reached maximum (180.9±32.6%) at the end of pregnancy. It decreased abruptly with start of labor, and free kallikrein was demonstrated in the circulating blood during labor. In pregnant rats (Wister descent rats), onset of labor was significantly prolonged (520.7±1.3 hours 564.0±0 hours) by FOY (a synthetic broad specturm serine protease inhibitor, 2mg daily intraperitoneal administration, n=4) as compared with saline control group. It can be therefore concluded that prekallikrein may relate to the labor mechanism.
(2) In women (n=5) with normal ovulation cycle, a significant transient fall of plasma prekallikrein was observed 72 hours before ovulation. The same event was also observed 21 hours before ovulation in the experimentally induced ovulation by PMS-HCG in rats. The experimental ovulation was suppressed by aprotinin.
