Moore J R, Turner B S, LaMont J T
Am J Physiol. 1984 Oct;247(4 Pt 1):G427-31. doi: 10.1152/ajpgi.1984.247.4.G427.
We studied the effects of hydrocortisone, an inhibitor of phospholipase A2, on the secretion of mucin and release of prostaglandins from guinea pig gallbladder explants. We measured mucin using [3H]glucosamine as a precursor and prostaglandins by radioimmunoassay of 6-keto-prostaglandin F1 alpha. Mucin secretion and prostaglandin release were studied under basal conditions and after arachidonate stimulation. Hydrocortisone sodium succinate reversibly inhibited basal secretion of mucin by 24% at 10(-5) M (P less than 0.05 compared with control) and 34% at 10(-4) M (P less than 0.01). Hydrocortisone, 10(-4) M, also reversibly inhibited arachidonate-stimulated secretion of mucin (P less than 0.01 compared with controls incubated with arachidonate alone). Release of prostaglandin F1 alpha was significantly inhibited by hydrocortisone under basal (P less than 0.01) and arachidonate-stimulated (P less than 0.01) conditions. The inhibitory effect of hydrocortisone was mediated by inhibition of hydrolysis of arachidonate from membrane phospholipids, suggesting that exogenous arachidonate is incorporated into membrane phospholipids prior to conversion to prostaglandins.
我们研究了磷脂酶A2抑制剂氢化可的松对豚鼠胆囊外植体粘蛋白分泌和前列腺素释放的影响。我们使用[3H]葡萄糖胺作为前体来测量粘蛋白，并通过对6-酮-前列腺素F1α进行放射免疫测定来检测前列腺素。在基础条件下以及花生四烯酸刺激后研究了粘蛋白分泌和前列腺素释放。氢化可的松琥珀酸钠在10^(-5)M时可逆地抑制基础粘蛋白分泌24%（与对照组相比P<0.05），在10^(-4)M时抑制34%（P<0.01）。10^(-4)M的氢化可的松也可逆地抑制花生四烯酸刺激的粘蛋白分泌（与单独用花生四烯酸孵育的对照组相比P<0.01）。在基础（P<0.01）和花生四烯酸刺激（P<0.01）条件下，氢化可的松显著抑制前列腺素F1α的释放。氢化可的松的抑制作用是通过抑制花生四烯酸从膜磷脂的水解介导的，这表明外源性花生四烯酸在转化为前列腺素之前被掺入膜磷脂中。
