Ferguson M K, Tzeng E
Department of Surgery, University of Chicago Medical Center, Illinois 60637.
J Surg Res. 1991 Dec;51(6):500-5. doi: 10.1016/0022-4804(91)90172-i.
Recent investigations have identified a class of outwardly rectifying potassium channels activated directly by arachidonic acid (AA) and select other fatty acids (FA) that inhibit smooth muscle contractions. We hypothesized that lymphatic smooth muscle contains similar fatty acid activated channels. Fresh porcine tracheobronchial lymphatic vessel rings were mounted in organ baths and connected to force-velocity transducers. Contractile responses were measured following exposure to histamine alone, with AA, and following AA washout, demonstrating a 40-55% inhibition of histamine-induced contractility by AA. Despite addition of indomethacin and nordihydroguaiaretic acid to inhibit formation of active AA metabolites, AA still attenuated contractility by 24-31%. Myristic acid and linoelaidic acid, FA's that are not substrates for cyclooxygenase or 5-lipoxygenase, inhibited histamine-induced contractility by 19 and 15%, respectively. The effects of AA and the other FA's were eliminated by exposure to a high potassium solution. The data support the existence of AA-activated hyperpolarizing potassium channels in lymphatic smooth muscle. Arachidonic acid, in addition to its metabolites, may play a direct role in regulating lymphatic smooth muscle tone.
最近的研究发现了一类由花生四烯酸（AA）直接激活的外向整流钾通道，并选择了其他抑制平滑肌收缩的脂肪酸（FA）。我们假设淋巴管平滑肌含有类似的脂肪酸激活通道。将新鲜猪气管支气管淋巴管环安装在器官浴中，并连接到力-速度换能器。在单独暴露于组胺、与AA一起以及AA洗脱后测量收缩反应，结果表明AA对组胺诱导的收缩性有40-55%的抑制作用。尽管添加了吲哚美辛和去甲二氢愈创木酸以抑制活性AA代谢产物的形成，但AA仍使收缩性减弱了24-31%。肉豆蔻酸和反式亚油酸，这两种不是环氧化酶或5-脂氧合酶底物的脂肪酸，分别抑制组胺诱导的收缩性19%和15%。暴露于高钾溶液可消除AA和其他FA的作用。这些数据支持淋巴管平滑肌中存在AA激活的超极化钾通道。花生四烯酸除了其代谢产物外，可能在调节淋巴管平滑肌张力中起直接作用。
