Contrast media induced apoptosis in renal tubular cells via the activation of p38 mitogen-activated protein kinase / 中华肾脏病杂志

ABSTRACT

Objective To investigate whether the effect of contrast media on renal tubular cell apoptosis is mediated via mitogen activated protein kinase(MAPK) activation. Methods NRK 52E cells were incubated in cell culture media[+1%fatel calf serum (FCS)] containing buffer (control) or increasing concentrations of diatrizoate or iohexol for various time periods. In separate experiments, NRK 52E cells were incubated with diatrizoate in the presence of 10 or 20 ?mol/L SB203580, an inhibitor of p38 MAPK, for 4 h. Cell membrane integrity was assessed by trypan blue exclusion experiment. Apoptosis was assessed by flow cytometric DNA analysis, FITC Annexin Ⅴbinding/PI staining and electron microscopy. MAPK activity and phosphorylation was evaluated by immunoprecipitation and Western blot analysis. Results Diatrizoate, a kind of hyperosmolal contrast media, induced apoptosis in cultured NRK 52E cells in an osmotic pressure and duration dependent manner. Iohexol, another kind of less hyperosmolal contrast media, could not induce NRK 52E cells apoptosis. In NRK 52E cells incubated with diatrizoate, the level of p38 MAPK phosphorylation and activity increased after 15 min, and remained elevated even at 1 h. In contrast, the level of total p38 protein was not changed in whole experimental period. SB203580 significantly inhibited apoptosis in NRK 52E cells incubated with diatrizoate. The level of p44/p42 MAPK phosphorylation was not changed in whole experimental period. Conclusions Contrast media induces apoptosis in cultured NRK 52E cells in an osmotic pressure and duration dependent manner, which is related to the hypertonicity of contrast media. Contrast media induces apoptosis in NRK 52E cells via activation of p38 MAPK.