Figure 2.

Extracellular regulated protein kinase-1 and -2 (ERK1/2) and p38 protein expression under hypoxic condition in NRK-52E cells. Rat kidney epithelial cells (NRK-52E) were exposed to hypoxia at 1% O₂ for 24 to 72 h. (A) Representative Western blots of ERK1/2 and p38 protein. (B) Relative quantitation of phosphorylated ERK1/2 (P-ERK1/2)/total ERK1/2 (T-ERK1/2). (C) Relative quantitation of phosphorylated p38 (P-p38)/total p38 (T-p38). β-actin was detected as an internal standard. At least 3 independent experiments were carried out in all groups. All the blots were normalized to β-actin, which was presented as 100% control. H, hypoxia; C, normoxic control. *P < 0.05. **P < 0.01. ***P < 0.001. Note that hypoxia at 1% O₂ for 24 to 72 h significantly increased the expression of phosphorylated ERK1/2 and p38 but did not induce any appreciable changes in total ERK1/2 and p38 protein in NRK-52E cells.