吲哚美辛改变培养的兔非色素睫状上皮中钠钾ATP酶对蛋白激酶C激活的反应。

Indomethacin alters the Na,K-ATPase response to protein kinase C activation in cultured rabbit nonpigmented ciliary epithelium.

作者信息

Delamere N A, Parkerson J, Hou Y

机构信息

Department of Ophthalmology and Visual Sciences, University of Louisville, Kentucky 40292, USA.

出版信息

Invest Ophthalmol Vis Sci. 1997 Apr;38(5):866-75.

PMID:9112982

Abstract

PURPOSE

To test whether prostaglandin E2 (PGE2) is generated by cultured nonpigmented ciliary epithelial (NPE) cells treated with the phorbol ester, phorbol dibutyrate (PDBu), an activator of protein kinase C. In addition, the authors tested whether indomethacin, a cyclooxygenase inhibitor, influences the stimulation of active sodium-potassium transport observed in PDBu-treated cells.

METHODS

A cell line derived from rabbit NPE was used in this study. PGE2 was measured by an enzyme-linked immunosorbent assay technique. Ouabain-sensitive potassium (86Rb) uptake was measured as an index of active sodium-potassium (Na, K-ATPase-mediated) transport. Ouabain-sensitive ATP hydrolysis (Na,K-ATPase activity) also was measured. Cell sodium and potassium content was determined by atomic absorption spectrophotometry.

RESULTS

Marked PGE2 generation was observed in PDBu-treated cells. Indomethacin abolished the PGE2 response. Ouabain-sensitive potassium (86Rb) uptake was stimulated approximately 40% in cells exposed to PDBu, but a stimulation of > 100% was observed in cells exposed to PDBu in the presence of indomethacin. Added alone, indomethacin did not alter ouabain-sensitive potassium (86Rb) uptake. Neither nordihydroguaiaretic acid (a lipoxygenase inhibitor) nor ethoxyresorufin (a cytochrome P450 inhibitor) altered the 86Rb uptake response to PDBu. Sodium and cyclic adenosine monophosphate content was unchanged in cells treated with PDBu + indomethacin.

CONCLUSIONS

In PDBu-treated cells, there may be generation of cyclooxygenase metabolites of arachidonic acid that inhibit Na, K-ATPase activity, suppressing the stimulatory effect of PDBu on active sodium-potassium transport. Based on the observation that PGE2 can inhibit Na, K-ATPase activity and also inhibit ouabain-sensitive potassium (86Rb) uptake, the authors suggest PGE2 may influence the Na,K-ATPase response to the activation of protein kinase C in NPE cells.

摘要

目的

检测用佛波酯（佛波醇二丁酸酯，PDBu）处理培养的无色素睫状上皮（NPE）细胞时是否会生成前列腺素E2（PGE2），PDBu是一种蛋白激酶C激活剂。此外，作者还检测了环氧化酶抑制剂吲哚美辛是否会影响在PDBu处理的细胞中观察到的活性钠钾转运刺激。

方法

本研究使用了源自兔NPE的细胞系。通过酶联免疫吸附测定技术测量PGE2。测量哇巴因敏感的钾（86Rb）摄取作为活性钠钾（由Na，K - ATP酶介导）转运的指标。还测量了哇巴因敏感的ATP水解（Na，K - ATP酶活性）。通过原子吸收分光光度法测定细胞钠和钾含量。

结果

在PDBu处理的细胞中观察到显著的PGE2生成。吲哚美辛消除了PGE2反应。在暴露于PDBu的细胞中，哇巴因敏感的钾（86Rb）摄取增加了约40%，但在吲哚美辛存在下暴露于PDBu的细胞中观察到增加超过100%。单独添加吲哚美辛不会改变哇巴因敏感的钾（86Rb）摄取。去甲二氢愈创木酸（一种脂氧合酶抑制剂）和乙氧基试卤灵（一种细胞色素P450抑制剂）均未改变对PDBu的86Rb摄取反应。用PDBu + 吲哚美辛处理的细胞中钠和环磷酸腺苷含量未改变。

结论

在PDBu处理的细胞中，可能会生成花生四烯酸的环氧化酶代谢产物，其抑制Na，K - ATP酶活性，抑制PDBu对活性钠钾转运的刺激作用。基于PGE2可抑制Na，K - ATP酶活性且还可抑制哇巴因敏感的钾（86Rb）摄取这一观察结果，作者认为PGE2可能影响NPE细胞中Na，K - ATP酶对蛋白激酶C激活的反应。