The differences in 12-hydroxyeicosatetraenoic acid and thromboxane B2 release from guinea pig platelets.
Anti-12(S)-hydroxyeicosatetraenoic acid (12-HETE)-antibody and anti-thromboxane B2 (TXB2)-antibody were generated and applied to the radioimmunoassay. The detection limit for 12-HETE was 16 pg. The cross-reactivities of anti-12-HETE-antibody were 4.6% for 15-HETE, 0.18% for 5-HETE and below 0.15% for leukotrienes and prostaglandins (PGs). 12-HETE and TXB2 released from guinea pig platelets were measured by radioimmunoassay. Platelet activating factor (PAF) at 10(-9) M induced the aggregation of platelets, the releases of immunoreactive-12-HETE (1.8 +/- 1.2 ng/10(8) platelets, mean +/- S.D.) and immunoreactive-TXB2 (18.5 +/- 17.3 ng/10(8) platelets). Collagen at 1 microgram/ml also evoked platelet aggregation, the releases of immunoreactive-12-HETE (2.7 +/- 1.1 ng/10(8) platelets) and immunoreactive-TXB2 (11.8 +/- 4.6 ng/10(8) platelets). By the stimulation with these compounds, TXB2 was produced in a greater amount than 12-HETE from guinea pig platelets. Although 10(-7) M and 10(-6) M U46619, a TXA2 mimetic, caused platelet aggregation, arachidonic acid metabolites were not released. These data suggest the presence of different mechanisms of platelet activation depending on each stimulus.
Mike
I
I
Pharmaceutical Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Shizuoka, Japan.
Ichikawa
Y
Y
Shimizu
T
T
Honda
Z I
ZI
Seyama
Y
Y
Ishii
A
A
D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000818:Animals; D000906:Antibodies / Q000276:immunology; D001792:Blood Platelets / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000494:pharmacology; D003429:Cross Reactions; D006168:Guinea Pigs; D006893:Hydroxyeicosatetraenoic Acids / Q000097:blood* / Q000276:immunology; D008297:Male; D010972:Platelet Activating Factor / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D011863:Radioimmunoassay; D013929:Thromboxane B2 / Q000097:blood* / Q000276:immunology
D000906:Antibodies; D006893:Hydroxyeicosatetraenoic Acids; D010972:Platelet Activating Factor; D011450:Prostaglandin Endoperoxides, Synthetic; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; D013929:Thromboxane B2; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D003094:Collagen