MECHANISM OF 5-HYDROXYTRYPTAMINE RELEASE INDUCED BY BACTERIAL LIPOPOLYSACCHARIDE FROM BLOOD PLATELETS

Abstract

Morphological studies on the mechanism of 5-HT release induced by bacterial lipopolysaccharide (LPS) from rabbit platelet were studied and compared with those of reserpine, chlor-promazine, phospholipase A, n-decylamine and tyramine. In the fluorescence microscopic studies, LPS and reserpine caused a reduction in yellowish fluorescence of 5-HT without affecting morphological structure. In the electron microscopic studies, LPS and reserpine caused disappearance of osmiophilic granules and increase in number of vacuoles of platelets. Chlorpromazine, phospholipase A and n-decylamine induced some alteration of ultrastructure of platelet, the disruption of the limiting membrane and a leak of cytoplasmic material. Tyramine released 5-HT from platelet without showing any morphological alteration.