3.10. Effects on Intracellular Endothelin-1

The effect of the synthesized peptide (APKIEEV) on intracellular endothelin-1 (ET-1) was demonstrated using the same procedure described by Zheng et al. [5]. Briefly, EA.hy926 cells were cultured in DMEM at 37 °C for 24 h in a humidified atmosphere with 5% CO₂. The DMEM contains streptomycin (100 μg/mL), fetal bovine serum (100 μg/mL) and non-essential amino acid (10 mg/mL). The cells were transferred into 96-well plates and cultured in DMEM at 37 °C for 24 h, and then subjected to treatment of the synthesized peptide with different concentrations (0.5, 1.0 and 1.5 mg/mL) for 48 h; while, captopril (1 mg/mL) was used as the comparison. The growth medium in each well was collected and the ET-1 content was determined using an ET-1 Elisa kit.