STUDIES ON PLASMA FACTOR INVOLVED IN 5-HYDROXYTRYPTAMINE RELEASE FROM BLOOD PLATELETS BY BACTERIAL ENDOTOXIN
III. MECHANISM OF ACTION OF 5-HYDROXYTRYPTAMINE RELEASING FACTOR
1972 Volume 22 Issue 1 Pages 79-87
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1972 Volume 22 Issue 1 Pages 79-87
It has been well established that 5-hydroxytryptamine (5HT) release from blood platelets by bacterial endotoxin (lipopolysaccharide, LPS) requires the presence of plasma factor and calcium ion (1-4). Recently, separation and purification of plasma factor with 5HT releasing activity has been reported by Nomura and Takagi (5, 6). They estimated that this factor could be mainly prothrombin-like protein, however, the mechanism of 5HT release by this factor is unknown. Thrombin has been considered an enzyme with 5HT releasing activity from the blood platelets and mechanism of its action was studied by Gainter et al. (7), Pletscher et al. (8) and Markwardt et al. (9-11).
The purpose of the present experiment is to investigate the mechanism of action of 5HT releasing factor purified using a previous method (6), as well as making a comparison with thrombin.
