Heavey D J, Ernst P B, Stevens R L, Befus A D, Bienenstock J, Austen K F
Department of Medicine, Harvard Medical School, Boston, MA 02115.
J Immunol. 1988 Mar 15;140(6):1953-7.
Mucosal mast cells (MMC) were isolated from the intestine of Nippostrongylus brasiliensis-infected rats and then activated with Ag or with anti-IgE in order to assess their metabolism of arachidonic acid to leukotriene (LT) C4, LTB4, and prostaglandin D2 (PGD2). After challenge of MMC preparations of 19 +/- 1% purity with five worm equivalents of N. brasiliensis Ag, the net formation of immunoreactive equivalents of LTC4, LTB4, and PGD2 was 58 +/- 8.3, 22 +/- 4.5, and 22 +/- 3.4 ng/10(6) mast cells, respectively (mean +/- SE, n = 7). When MMC preparations of 56 +/- 9% purity were activated by Ag, the net generation of immunoreactive equivalents of LTC4, LTB4, and PGD2/10(6) MMC was 107 +/- 15, 17 +/- 5.4, and 35 +/- 18 ng, respectively. These data indicate that the three eicosanoids originated from the MMC rather than from a contaminating cell. Analysis by reverse phase HPLC of the C-6 sulfidopeptide leukotrienes present in the supernatants of the activated MMC preparations of lower purity revealed LTC4, LTD4, and LTE4. In a higher purity MMC preparation only LTC4 was present, suggesting that other cell types in the mucosa are able to metabolize LTC4 to LTD4 and LTE4. The release of histamine and the generation of eicosanoids from intestinal MMC and from peritoneal cavity-derived connective tissue-type mast cells (CTMC) isolated from the same N. brasiliensis-infected rats were compared. When challenged with anti-IgE, these MMC released 165 +/- 41 ng of histamine/10(6) mast cells, and generated 29 +/- 3.6, 12 +/- 4.2, and 4.7 +/- 1.0 ng (mean +/- SE, n = 3) of immunoreactive equivalents of LTC4, LTB4, and PGD2/10(6) mast cells, respectively. In contrast, CTMC isolated from the same animals and activated with the same dose of anti-IgE released approximately 35 times more histamine (5700 +/- 650 ng/10(6) CTMC), generated 7.5 +/- 2.3 ng of PGD2/10(6) mast cells, and failed to release LTC4 or LTB4. These studies establish, that upon immunologic activation, rat MMC and CTMC differ in their quantitative release of histamine and in their metabolism of arachidonic acid to LTC4 and LTB4.
从感染巴西日圆线虫的大鼠肠道中分离出黏膜肥大细胞（MMC），然后用抗原或抗IgE激活，以评估其将花生四烯酸代谢为白三烯（LT）C4、LTB4和前列腺素D2（PGD2）的情况。用相当于五条虫的巴西日圆线虫抗原刺激纯度为19±1%的MMC制剂后，LTC4、LTB4和PGD2免疫反应性当量的净生成量分别为58±8.3、22±4.5和22±3.4 ng/10⁶个肥大细胞（平均值±标准误，n = 7）。当用抗原激活纯度为56±9%的MMC制剂时，LTC4、LTB4和PGD2/10⁶个MMC的免疫反应性当量的净生成量分别为107±15、17±5.4和35±18 ng。这些数据表明，这三种类二十烷酸源自MMC而非污染细胞。通过反相高效液相色谱法分析低纯度激活MMC制剂上清液中存在的C-6硫醚肽白三烯，发现了LTC4、LTD4和LTE4。在更高纯度的MMC制剂中仅存在LTC4，这表明黏膜中的其他细胞类型能够将LTC4代谢为LTD4和LTE4。比较了从同一感染巴西日圆线虫的大鼠中分离出的肠道MMC和腹腔来源的结缔组织型肥大细胞（CTMC）中组胺的释放以及类二十烷酸的生成情况。用抗IgE刺激时，这些MMC释放出165±41 ng组胺/10⁶个肥大细胞，并分别生成29±3.6、12±4.2和4.7±1.0 ng（平均值±标准误，n = 3）的LTC4、LTB4和PGD2免疫反应性当量/10⁶个肥大细胞。相比之下，从同一动物分离并用相同剂量抗IgE激活的CTMC释放的组胺大约多35倍（5700±650 ng/10⁶个CTMC），生成7.5±2.3 ng PGD2/10⁶个肥大细胞，且未释放LTC4或LTB4。这些研究表明，在免疫激活后，大鼠MMC和CTMC在组胺的定量释放以及花生四烯酸代谢为LTC4和LTB4方面存在差异。
