Effects of adrenochrome and epinephrine on human arterial endothelial cells in vitro

Abstract

The effects of adrenochrome and epinephrine were investigated in cultured human umbilical arterial endothelial cells. The cells were exposed to either adrenochrome or epinephrine at levels of 50 and 200 microM, respectively, up to 24 hrs. At 3, 5, 7 and 24 hrs of the designed harvesting time, [3H]thymidine incorporation, protein content, [3H]cholesterol uptake, prostacyclin production and lipid peroxidation were measured. We found that adrenochrome at a level of 200 microM inhibited [3H]thymidine incorporation, decreased protein content, stimulated [3H]cholesterol uptake, and decreased prostacyclin production after 3, 5, 24 and 5 hrs of exposure, respectively, compared with control. It took 24 hrs however for epinephrine at a level of 200 microM to inhibit [3H]thymidine incorporation and prostacyclin production. When the concentration was reduced to 50 microM, only adrenochrome inhibited [3H]thymidine incorporation after 24 hrs of treatment. Both adrenochrome and epinephrine had no effect on lipid peroxidation. We suggest that atherogenic changes found in severe hypertension may be due to abnormal high concentration of epinephrine, especially oxidized epinephrine, on endothelial cell functions, such as DNA synthesis, cholesterol uptake and prostacyclin production.