STUDIES ON PLASMA FACTOR INVOLVED IN 5-HYDROXYTRYPTAMINE RELEASE FROM BLOOD PLATELETS BY BACTERIAL ENDOTOXIN
II. PURIFICATION OF 5-HYDROXYTRYPTAMINE RELEASING FACTOR FROM RABBIT PLASMA
1972 Volume 22 Issue 1 Pages 71-77
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1972 Volume 22 Issue 1 Pages 71-77
Previous studies have demonstrated that 5-hydroxytryptamine (5HT) released from blood platelets by bacterial endotoxin (lipopolysaccharide; LPS) requires the presence of calcium ion and plasma factor and that heparin inhibits its release (1-5). Recently, Nomura and Takagi (6) have separated the 5HT releasing factor from rabbit plasma by gel filtration on a Sephadex G-150 column. They have suggested that the plasma factor with 5HT releasing activity is a protein with a molecular wt. of approx. 110, 000 and that 5HT release induced by LPS could be mediated through antagonism by LPS to the inhibitory effect of heparin on the 5HT releasing plasma factor, and also that activity of the 5HT releasing factor in plasma could be regulated by heparin and the anti-5HT releasing factor existing in the albumin fraction.
The present report describes studies on the further purification of the 5HT releasing factor in rabbit plasma and its properties.
