Department of Chemical and Materials Engineering, Chinese Culture University, Shih-Lin, Taipei 11114, Taiwan, Republic of China.
Toxicol Sci. 2010 Dec;118(2):411-9. doi: 10.1093/toxsci/kfq274. Epub 2010 Sep 13.
Alkylphenol ethoxylate, consisting of ∼80% nonylphenol ethoxylate (NPEO), is a major group of nonionic surfactant. The primary degradation product of NPEO, nonylphenol (NP), interferes with reproduction, induces cell death in gonads, and leads to changes in other reproductive parameters. With such apparent stress, NP is believed to induce stress response mechanism, i.e., adrenal cortical hormone. However, the effects and action mechanisms of NP on rat adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of NP on corticosterone release. ZFR cells were incubated with NP in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3',5'-adenosine monophosphate (8-Br-cAMP), forskolin (FSK), 25-hydroxyl cholesterol (25-OH-cholesterol), pregnenolone, progesterone, or deoxycorticosterone at 37°C for 1 h. The concentrations of corticosterone or pregnenolone in the spent media were measured by radioimmunoassay. The expressions of steroidogenic acute regulatory (StAR) protein, cytochrome P450 side-chain cleavage (P450scc) protein, and 11β-hydroxylase in the cells were measured by Western blot. The data demonstrated that (1) NP stimulated corticosterone release induced by ACTH, 8-Br-cAMP, FSK, 25-OH-cholesterol, pregnenolone, progesterone, or deoxycorticosterone; (2) NP significantly increased pregnenolone release in the control, 25-OH-cholesterol, trilostane, and 25-OH-cholesterol + trilostane groups; (3) NP-stimulated corticosterone release was estrogen receptor dependent, but mediated by nitric oxide and p38 mitogen-activated protein kinase pathway independent; and (4) NP did not affect StAR, 11β-hydroxylase, or P450scc protein expression. These results suggest that NP acts directly on rat ZFR cells to stimulate corticosterone release and that the stimulation mechanism of NP mediates through post-cAMP corticosterone manufacture enzymes, i.e., P450scc and 11β-hydroxylase.
烷基酚聚氧乙烯醚，主要由 80%的壬基酚聚氧乙烯醚（NPEO）组成，是一类主要的非离子表面活性剂。NPEO 的主要降解产物壬基酚（NP）会干扰生殖功能，导致性腺细胞死亡，并导致其他生殖参数发生变化。由于存在这种明显的应激，NP 被认为会诱导应激反应机制，即肾上腺皮质激素。然而，NP 对大鼠肾上腺束状带网状带（ZFR）细胞的作用和作用机制尚不清楚。本研究探讨了 NP 对皮质酮释放的影响。将 ZFR 细胞与 NP 一起孵育，在存在或不存在促肾上腺皮质激素（ACTH）、8-溴环磷酸腺苷（8-Br-cAMP）、佛司可林（FSK）、25-羟胆固醇（25-OH-cholesterol）、孕烯醇酮、孕酮或脱氧皮质酮的情况下，在 37°C 下孵育 1 小时。用过的培养基中的皮质酮或孕烯醇酮的浓度通过放射免疫法测定。用 Western blot 法测定细胞中类固醇急性调节蛋白（StAR）蛋白、细胞色素 P450 侧链裂解酶（P450scc）蛋白和 11β-羟化酶的表达。数据表明：（1）NP 刺激了 ACTH、8-Br-cAMP、FSK、25-OH-cholesterol、孕烯醇酮、孕酮或脱氧皮质酮诱导的皮质酮释放；（2）NP 显著增加了对照、25-OH-cholesterol、曲洛司坦和 25-OH-cholesterol+曲洛司坦组的孕烯醇酮释放；（3）NP 刺激的皮质酮释放依赖于雌激素受体，但通过独立的一氧化氮和 p38 丝裂原活化蛋白激酶途径介导；（4）NP 不影响 StAR、11β-羟化酶或 P450scc 蛋白表达。这些结果表明，NP 直接作用于大鼠 ZFR 细胞，刺激皮质酮释放，而 NP 的刺激机制通过 cAMP 后皮质酮制造酶，即 P450scc 和 11β-羟化酶介导。
