title: Platelet 5-hydroxytryptamine release and aggregation promoted by cotton bracts tannin.
abstract: The effect of aqueous extracts of cotton bract (CBE) on platelet secretion and aggregation was examined by using washed bovine and human platelets. The CBE promoted the release of 75% to 90% of the 5-hydroxytryptamine (5-HT) stored in both human and bovine platelets in a dose-dependent manner. This release reaction occurred without the lysis of the platelets and was not inhibited by indomethacin, 2-deoxyglucose, or KCN. Fractionation of the CBE indicated that the platelet secretagogue present in the CBE was the condensed polyphenol, tannin. In addition to promoting the secretion of 5-HT, tannin also aggregated the platelets in a dose-dependent manner. We conclude that the secretion of platelet 5-HT and the aggregation of platelets by tannin could potentially contribute to the pulmonary symptoms associated with byssinosis.
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002095:Byssinosis / Q000378:metabolism; D002417:Cattle; D003847:Deoxyglucose / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D003368:Gossypium; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism*; D013634:Tannins / Q000494:pharmacology*
chemical_list: D013634:Tannins; D012701:Serotonin; D003847:Deoxyglucose; D007770:L-Lactate Dehydrogenase; D007213:Indomethacin