To clarify the role of platelets in the pathogenesis of bronchial asthma, the production of 12-hydroxyeicosatetraenoic acid(12HETE) from platelets of asthmatics was examined by high performance liquid chromatography(HPLC). The effect of platelets on lymphocyte function was also studied by lymphocyte blastogenesis. The results were as follows : 1) The production of 12HETE from platelets of asthmatics were significantly higher than that of normal subjects(p<0.01). 2) Blastogenesis of lymphocytes was significantly suppressed by addition of platelets(p<0.05). 3) Blastogenesis of lymphocytes was significantly suppressed by addition of more than 12.5ng/ml of 12HETE, 10ng/ml of transforming growth factorβ(TGE-β) or 50ng/ml of serotonin.
These results suggest that platelets play an important role in the pathogenesis of asthmatic responses mediated by activated lymphocytes.