高渗应激对TRH诱导的GH4C1大鼠垂体细胞中Na+/H+交换激活的启动效应。

Priming effect of hyperosmotic stress on TRH-induced activation of Na+/H+ exchange in GH4C1 rat pituitary cells.

作者信息

Törnquist K, Stewen P

机构信息

Endocrine Research Laboratory, University of Helsinki, Finland.

出版信息

Biochem Biophys Res Commun. 1990 Oct 30;172(2):913-8. doi: 10.1016/0006-291x(90)90762-c.

DOI:10.1016/0006-291x(90)90762-c

PMID:2173584

Abstract

The effect of mild hyperosmotic stress on cytosolic pH (pHi) alone, and in combination with thyrotropin-releasing hormone (TRH) or the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA) was investigated in GH4C1 cells at resting pHi. Hyperosmotic stress induced by addition of 50 mM choline was without an effect on pHi. In cells stimulated with either TRH or TPA after choline, pHi increased 0.15 +/- 0.05 and 0.14 +/- 0.03 pH units, respectively (mean +/- SD). A similar response was obtained if TRH or TPA was added prior to choline. The effect was abolished by replacing extracellular Na+ with choline+, and by pretreatment of the cells with amiloride, indicating that the change in pHi probably was dependent on activation of Na+/H+ exchange. The results thus indicate that, in GH4C1 cells, hyperosmotic stress in combination with TRH or TPA can activate Na+/H+ exchange at resting pHi levels.

摘要

在静息胞质pH（pHi）条件下，研究了轻度高渗应激单独作用以及与促甲状腺激素释放激素（TRH）或佛波酯12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯（TPA）联合作用对GH4C1细胞的影响。添加50 mM胆碱诱导的高渗应激对pHi无影响。在胆碱处理后用TRH或TPA刺激的细胞中，pHi分别升高0.15±0.05和0.14±0.03 pH单位（平均值±标准差）。如果在胆碱之前添加TRH或TPA，也会得到类似的反应。用胆碱 + 替代细胞外Na + 以及用氨氯吡咪预处理细胞可消除该效应，这表明pHi的变化可能依赖于Na + /H + 交换的激活。因此，结果表明，在GH4C1细胞中，高渗应激与TRH或TPA联合作用可在静息pHi水平激活Na + /H + 交换。