Dartois E, Bouton M M
Biochem Biophys Res Commun. 1986 Jul 16;138(1):323-9. doi: 10.1016/0006-291x(86)90283-4.
In pituitary cells in primary culture, ACTH and PGE2 secretions can be simultaneously stimulated by TPA, in the presence of Ca2+. However, whilst PGE2 secretion is under an absolute requirement for Ca2+, ACTH secretion is not. Both secretions are inhibited by dexamethasone but to various extents: PGE2 release is abolished in the presence of dexamethasone whilst only 35% of the TPA-induced ACTH release is sensitive to dexamethasone. Similar inhibitory effects are observed with mepacrine, a PLA2-inhibitor, suggesting that PLA2-activation could be related to these secretory process. Since PLA2-inhibition by dexamethasone is claimed to be mediated via lipocortin, these results suggest that a lipocortin-like protein is present in pituitary cells and could be involved in the TPA-induced secretions of PGE2 and ACTH.
在原代培养的垂体细胞中，在有Ca2+存在的情况下，佛波酯（TPA）可同时刺激促肾上腺皮质激素（ACTH）和前列腺素E2（PGE2）的分泌。然而，虽然PGE2的分泌绝对需要Ca2+，但ACTH的分泌则不然。两种分泌均受到地塞米松的抑制，但程度不同：在地塞米松存在的情况下，PGE2的释放被消除，而TPA诱导的ACTH释放只有35%对地塞米松敏感。用磷脂酶A2（PLA2）抑制剂米帕林也观察到类似的抑制作用，这表明PLA2的激活可能与这些分泌过程有关。由于地塞米松对PLA2的抑制作用据称是通过脂皮质素介导的，这些结果表明垂体细胞中存在一种脂皮质素样蛋白，并且可能参与TPA诱导的PGE2和ACTH的分泌。
