Figure 5. Hydrogen peroxide treatment of NLC cells causes a down-regulation in expression of Ca²⁺ extrusion system (NCX-1, PMCA-1, and PMCA-4) expression. NLC cells obtained from 3 donors (N1, N2, and N3) were treated with 200 µM H₂0₂ for 1 h, RNA isolated and gene expression of NCX-1, PMCA-1, and PMCA-4 was analyzed by quantitative PCR. Control (C) NLC cells were included for expressional comparison and assigned the arbitrary value of 1. Introduction of H₂O₂ significantly reduced expression of Ca²⁺ extrusions systems (NCX-1, PMCA-1, and PMCA-4) in some cell lines. Although, not all of the reductions are statistically significant; most approach significance and exhibit a downward trend. Results are representative of 3 individual experiments and significant results are denoted by * (p<0.05).