Cattell V, Cook H T, Smith J, Salmon J A, Moncada S
Nephrol Dial Transplant. 1987;2(3):154-7.
The production of the lipoxygenase metabolite of arachidonic acid, leukotriene B4 (LTB4) by normal rat glomeruli has been studied. Isolated glomeruli from saline-perfused rat kidneys were incubated in Kreb's buffer for 15 min at 37 degrees C. The concentrations of LTB4 and other eicosanoids in cell-free supernatants were determined by direct radioimmunoassays (RIA). Mean basal syntheses of eicosanoids were: thromboxane B2 (TXB2) 0.77 +/- 0.13, prostaglandin (PG) E2 0.40 +/- 0.05, 6-keto-PGF1 alpha 0.38 +/- 0.06 ng/mg glomerular protein (mean +/- SEM n = 8). In these assays immunoreactive LTB4 synthesis was 0.12 +/- 0.02 ng/mg. In samples incubated with BW755C, 50 micrograms/ml, an inhibitor of arachidonate metabolism via both the cyclo-oxygenase and lipoxygenase pathways, there was more than 80% inhibition of the synthesis of TXB2, PGE2 and 6-keto-PGF1 alpha. However, immunoreactive LTB4 was only reduced by 44%, suggesting the presence of other materials which cross-react in the RIA. The presence of authentic LTB4 in the supernatants was confirmed after extraction and high-pressure liquid chromatography (HPLC). This material represented 25% of the original material detected by RIA. Although the physiological role of LTB4 in the normal state is unknown, its chemotactic activity may be of great significance during glomerular inflammation.
已对正常大鼠肾小球中花生四烯酸的脂氧合酶代谢产物白三烯B4（LTB4）的生成进行了研究。将来自经盐水灌注的大鼠肾脏的分离肾小球在37℃的Krebs缓冲液中孵育15分钟。通过直接放射免疫测定法（RIA）测定无细胞上清液中LTB4和其他类花生酸的浓度。类花生酸的平均基础合成量为：血栓素B2（TXB2）0.77±0.13、前列腺素（PG）E2 0.40±0.05、6-酮-PGF1α 0.38±0.06 ng/mg肾小球蛋白（平均值±标准误，n = 8）。在这些测定中，免疫反应性LTB4的合成量为0.12±0.02 ng/mg。在用BW755C（50μg/ml，一种通过环氧化酶和脂氧合酶途径抑制花生四烯酸代谢的抑制剂）孵育的样品中，TXB2、PGE2和6-酮-PGF1α的合成受到了超过80%的抑制。然而，免疫反应性LTB4仅减少了44%，这表明存在其他在RIA中发生交叉反应的物质。经提取和高压液相色谱法（HPLC）后，确认了上清液中存在真实的LTB4。该物质占RIA检测到的原始物质的25%。虽然LTB4在正常状态下的生理作用尚不清楚，但其趋化活性在肾小球炎症期间可能具有重要意义。
