PLATELET 5-HYDROXYTRYPTAMINE RELEASE AND AGGREGATION PROMOTED BY COTTON BRACTS TANNIN

  • 1 January 1984
    • journal article
    • research article
    • Vol. 103  (1) , 152-160
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. Thus, the secretion of platelet 5-HT and the aggregation of platelets by tannin could potentially contribute to the pulmonary symptoms associated with byssinosis.