Interaction of leukotrienes with other mediators in pathological models and its regulation by drags.

1)中性粒细胞外渗：对仓鼠颊袋微循环的显微分析显示，局部应用白三烯B_4后，有五步外渗中性粒细胞。内皮细胞的粘附是由中性粒细胞的膜改变引起的，在LTB_4暴露后不到4.5秒就发生了粘附，并被CD18抗体抑制，表明粘附不是由新合成的蛋白引起的，而是由粘附分子的激活引起的，CD_<11>/CD_<18>。小动脉灌注LTB_4不诱导粘附，静脉灌注LTB_4不诱导粘附，且粘附被抗ICAM-1抗体抑制，说明ICAM-1不诱导组织形成，通常只存在于静脉内皮细胞中。2)乙醇诱导的胃粘膜损伤：30- 50%乙醇对大鼠胃粘膜下微循环的显微观察表明，这种损伤是由粘膜集合小静脉收缩、收缩和粘膜血流阻塞引起的。乙醇和外源性LTC_4作用于粘膜微血管收缩后，胃壁产生LTC_4。用抗5-脂氧合酶抗体对胃粘膜粘膜型肥大细胞进行选择性染色。暴露于乙醇后，胃腔内P物质和CGRP也增加。辣椒素预处理能抑制乙醇处理后收集小静脉的收缩，而旧的P物质拮抗剂spantide则不能。3)气道阻力：豚鼠静脉注射LTC_4和LTD_4，气道阻力增加，组织钾化肽分泌到呼吸道管腔，分泌量增加。LTC_4比LTD4更有效。血栓素（txa_2）和乙酰胆碱的释放依次诱导心肌细胞分泌钾likrein。缓激肽释放的缓激肽通过释放TXA_2和乙酰胆碱形成缓激肽分泌的正反馈回路。少

1) NEUTROPHIL EXTRAVASATION: Vital microscopic analyses in microcirculation of hamster cheek pouch revealed that after topical application of leukotriene (LT) B_4 extravasated neutrophils by five steps. Adhesion on endothelial cells was initiated by membrane changes of neutrophils, occurred less than 4.5 sec after exposure of LTB_4 and was inhibited by an antibody against CD18, indicating that adhesion was induced not by newly synthesized protein, but by activation of adhesion molecules, CD_<11>/CD_<18>. Intra-arteriolar infusion of LTB_4 did not induce the adhesion, intra-venular infusion did it and the adhesion was inhibited by an antibody against ICAM-1, indicating that ICAM-1 is not induced in the tissue, but normally present in only venular endothelial cells.2) ETHANOL-INDUCED GASTRIC MUCOSAL INJURY: Vital microscopic observation of the submucosal microcirculation of rat stomach after exposure of the gastric mucosa to 30-50 % ethanol revealed that this injury was induced by constr … More iction of the collecting venules of the mucosa and subsequent congestion of the mucosal blood flow. LTC_4 was generated in the gastric wall after ethanol and exogenous LTC_4 applied on the mucosal microvasculature constricted the collecting venules. The mucosal type mast cells in the gastric mucosa were selectively stained by an antibody against 5-lipoxygenase. Substance P and CGRP were also increased in the gastric lumen after exposure to ethanol. Constriction of the collecting venules after ethanol was inhibited by pretreatment with capsaicin, but not by spantide, an old Substance P antagonist.3) AIRWAY RESISTANCE: Intravenous injection of LTC_4 and LTD_4 to guinea pigs increased airway resistance and secreted tissue kallikrein into the lumen of the respiratory tract with increased secretion. LTC_4 was more potent than LTD4. The kallikrein secretion was induced by release of thromboxane (TX) A_2 and acetylcholine successively. Bradykinin released by kallikrein formed a positive feed back loop for secretion of kallikrein by release of TXA_2 and acetylcholine. Less