Sirois P, Roy S, Borgeat P, Picard S, Vallerand P
Prostaglandins Leukot Med. 1982 Feb;8(2):157-70. doi: 10.1016/s0262-1746(82)80008-5.
The mechanism of action of LTB4 has been investigated on the guinea-pig lung parenchymal strip. Mepacrine (20 microgram/ml), an inhibitor of phospholipase A2, abolished the action of LTB4 on parenchymal strips. Eicosatetraynoic acid (10 microgram/ml) and BW755C (40 microgram/ml) which are inhibitors of cyclooxygenase and lipoxygenase pathways, produced a marked inhibition of the lung strip contraction to LTB4. Similarly, aspirin (30 micrograms/ml) and flufenamate (1 microgram/ml) showed a strong inhibition of the contraction of parenchymal strips to LTB4; these results suggested that cyclooxygenase products mediate the action of LTB4. The response to LTB4 was unaffected by 15-hydroperoxyeicosatatraenoic acid (15-HPETE; 1 microgram/ml) while L8027 (25 ng/ml) reduced the contraction by 50%, suggesting that thromboxane A2 rather than prostacyclin was involved. Since parenchymal strips do not appear to be very sensitive to PGF2 alpha, PGE2 and the endoperoxides, and since effluents from LTB4-treated lungs produced contractions of lung strip and rabbit aorta which were reduced after 5 min. at 25 degrees, thromboxane A2 was postulated to mediate the lung effect of LTB4. The release of thromboxane B2 (TxB2) from lungs stimulated with LTB4 was confirmed by gas-chromatography-mass spectrometric (GC-MS) analyses.
已在豚鼠肺实质条上研究了白三烯B4（LTB4）的作用机制。磷脂酶A2抑制剂米帕林（20微克/毫升）可消除LTB4对实质条的作用。环氧化酶和脂氧合酶途径的抑制剂二十碳四烯炔酸（10微克/毫升）和BW755C（40微克/毫升）对肺条对LTB4的收缩产生明显抑制作用。同样，阿司匹林（30微克/毫升）和氟灭酸（1微克/毫升）对实质条对LTB4的收缩表现出强烈抑制作用；这些结果表明环氧化酶产物介导LTB4的作用。15-氢过氧二十碳四烯酸（15-HPETE；1微克/毫升）对LTB4的反应无影响，而L8027（25纳克/毫升）使收缩减少50%，这表明参与其中的是血栓素A2而非前列环素。由于实质条似乎对前列腺素F2α、前列腺素E2和内过氧化物不太敏感，且由于LTB4处理的肺的流出物可使肺条和兔主动脉收缩，在25℃下5分钟后收缩减弱，因此推测血栓素A2介导LTB4的肺效应。通过气相色谱-质谱（GC-MS）分析证实了LTB4刺激的肺中血栓素B2（TxB2）的释放。
