Open AccessTwo Distinct Effects of 125-Hydroxyeicosatetraenoic Acid on Platelet Aggregation by Zooxanthellatoxin-A and Ionomycin
Author(s) -
MunChual Rho,
Norimichi Nakahata,
Yasushi Ohizumi
Publication year - 1998
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.76.117
Subject(s) - ionomycin , arachidonic acid , chemistry , thromboxane b2 , platelet , ionophore , pharmacology , metabolite , medicine , endocrinology , biochemistry , intracellular , enzyme , membrane
The marine toxin zooxanthellatoxin-A (ZT-A) and the Ca2+ ionophore ionomycin caused aggregation in rabbit platelets. While ZT-A-induced platelet aggregation was inhibited by indomethacin, ionomycin-induced aggregation was potentiated by the drug. In contrast, both ZT-A- and ionomycin-induced accumulations of thromboxane B2 (TXB2), a stable metabolite of thromboxane A2 (TXA2), were completely inhibited by indomethacin. 12S-Hydroxyeicosatetraenoic acid (12-HETE), which could be accumulated in the presence of indomethacin, inhibited ZT-A-induced aggregation, but it potentiated the ionomycin-induced one. These results suggest that the different effects of indomethacin may be attributed to the distinct effects of 12-HETE on ZT-A- and ionomycin-induced platelet aggregations.