Ahlquist D A, Madson T H, Romero J C, Dozois R R, Malagelada J R
Am J Physiol. 1983 Feb;244(2):G131-7. doi: 10.1152/ajpgi.1983.244.2.G131.
The metabolism of [14C]arachidonic acid in whole homogenates of gastric corpus mucosa in the guinea pig was characterized. Identity of labeled products was validated by comigration against standards in multiple chromatographic systems and by selective synthesis inhibition. At near-physiological conditions, homogenates converted arachidonic acid to the cyclooxygenase products prostaglandins F2, E2, and D2, 6-keto-prostaglandin F1 alpha, and thromboxane B2 (in descending order of magnitude) and to a lipoxygenase product cochromatographing with 12-hydroxyeicosatetraenoic acid. However, dramatic qualitative and quantitative changes in this product profile were noted with relatively small changes in incubation temperature, substrate concentration, and especially pH. Whole homogenates generated more prostaglandin and in different proportions than did the microsomal fraction from an equal mass of mucosa. No catabolism of prostaglandin products was observed in whole homogenates. Tissue preparation and storage also influenced prostaglandin synthesis activity. These in vitro observations may have important implications for future studies of prostaglandin generation in small gastric mucosal biopsies.
对豚鼠胃体黏膜全匀浆中[14C]花生四烯酸的代谢进行了表征。通过在多个色谱系统中与标准品共迁移以及选择性合成抑制来验证标记产物的同一性。在接近生理条件下，匀浆将花生四烯酸转化为环氧化酶产物前列腺素F2、E2和D2、6-酮-前列腺素F1α以及血栓素B2（按含量递减顺序），并转化为与12-羟基二十碳四烯酸共色谱的脂氧合酶产物。然而，随着孵育温度、底物浓度尤其是pH值的相对较小变化，该产物谱出现了显著的定性和定量变化。与等量黏膜的微粒体部分相比，全匀浆产生的前列腺素更多且比例不同。在全匀浆中未观察到前列腺素产物的分解代谢。组织制备和储存也影响前列腺素合成活性。这些体外观察结果可能对未来小胃黏膜活检中前列腺素生成的研究具有重要意义。
