EFFECTS OF ADRENOCHROME AND EPINEPHRINE ON HUMAN ARTERIAL ENDOTHELIAL-CELLS IN-VITRO

The effects of adrenochrome and epinephrine were investigated in cultu red human umbilical arterial endothelial cells. The cells were exposed to either adrenochrome or epinephrine at levels of 50 and 200 mu M, r espectively, up to 24 hrs. At 3, 5, 7 and 24 hrs of the designed harve sting time, [H-3]thymidine incorporation, protein content, [H-3]choles terol uptake, prostacyclin production and lipid peroxidation were meas ured. We found that adrenochrome at a level of 200 mu M inhibited [H-3 ]thymidine incorporation, decreased protein content, stimulated [H-3]c holesterol uptake, and decreased prostacyclin production after 3, 5, 2 4 and 5 hrs of exposure, respectively, compared with control. It took 24 hrs however for epinephrine at a level of 200 mu M to inhibit [H-3] thymidine incorporation and prostacyclin production. When the concentr ation was reduced to 50 mu M, only adrenochrome inhibited [H-3]thymidi ne incorporation after 24 hrs of treatment. Both adrenochrome and epin ephrine had no effect on lipid peroxidation. We suggest that atherogen ic changes found in severe hypertension may be due to abnormal high co ncentration of epinephrine, especially oxidized epinephrine, on endoth elial cell functions, such as DNA synthesis, cholesterol uptake and pr ostacyclin production.