Pretreatment with Glutamine Attenuates Anoxia/Reoxygenation Injury of Human Proximal Renal Tubular Epithelial Cells via Induction of Heme Oxygenase-1

<i>Background/Aims:</i> Glutamine showed potential cytoprotective activity probably due to induction of heme oxygenase-1 (HO-1). We thus investigated the effect of glutamine in vitro on anoxia/reoxygenation (A/R) injury of renal tubular epithelial cells. <i>Methods:</i> Human proximal renal tubular epithelial cells (HK-2) were subjected to A/R with or without glutamine, after which viability and apoptosis of the cells were determined by MTT assay and annexin V flow cytometry, respectively. Meanwhile, expression of HO-1, caspase-3, Bcl-2 and inducible nitric oxide synthetase (iNOS) was measured by reverse transcriptase polymerase chain reaction and Western blot. <i>Results:</i> A/R significantly induced apoptosis of HK-2 cells, which was inhibited by glutamine, during which HO-1 was upregulated significantly, but nullified by p38MAPK inhibitor. Caspase-3 and iNOS increased after A/R; however, glutamine inhibited this potential. Opposite results were observed for Bcl-2. <i>Conclusion:</i> Glutamine prevents A/R injury of HK-2 cells through induction of HO-1 via a p38MAPK-dependent pathway, which plays a key role in the cytoprotective effect of glutamine.