Pretreatment of endothelium.
Hematin and iron deuteroporphyrin IX pretreatment of endothelium provided cell protection against hematin/H2O2–mediated lysis. Human umbilical vein endothelial cells were pretreated with control medium (first bar) or 10 μmol/L of ferriporphyrins, consisting of hematin (second bar), heme arginate (third bar), iron deuteroporphyrin IX,2,4-bis-sulfonate (fourth bar), iron coproporphyrin III (fifth bar), iron deuteroporphyrin IX,2,4-bis-glycol (sixth bar), or iron deuteroporphyrin IX (seventh bar), for 60 minutes, and the culture media were then replaced with ferriporphyrin-free medium for 15 hours. Endothelial cell oxidant stress was then provided by exposure of the cells to hematin (5 μmol/L) for 60 minutes followed by H2O2 (100 μmol/L) for 2 hours. Results are the specific cytotoxicity (mean ± SE) of 3 experiments performed in duplicate.
