Erythrocyte Catabolism by Macrophages In Vitro THE EFFECT OF HYDROCORTISONE ON ERYTHROPHAGOCYTOSIS AND ON THE INDUCTION OF HEME OXYGENASE

摘要: Abstract Phagocytosis of erythrocytes was studied in vitro an incubation system consisting rat peritoneal macrophages and antibody-coated 59Fe-labeled erythrocytes. The characterized terms the rate magnitude erythrophagocytosis, determined by interiorization 59Fe label. On 150 × 106 with 75 antibodycoated erythrocytes, erythrophagocytosis began within a few minutes essentially completed after 2 h when 50% offered red cells had been ingested macrophages. Heme oxygenase (HO) activity, which is very low native macrophages, increased 4- to 10- fold response erythrocytes; this enzyme stimulation occurred delay 3 relation erythrophagocytosis. Actinomycin D or puromycin prevented increase HO activity without affecting suggests that due substrate-mediated induction. Hydrocortisone (HC) (0.1 mg/ml medium) dissociated from induction, leaving former unimpaired but completely suppressing latter. suppressive effect HC on induction 5 mg glucose 0.02 U insulin/ml medium. In engaged also lowered removal medium reduced formation 14CO2 [1-14C]glucose. These results suggest hemoglobin requires intact transport metabolism glucose. Glucose utilization appears be impaired HC, restored additional insulin. findings plasma steroid concentrations pharmacological range could reduce bilirubin phagocytic vivo sequestration degradation This provides possible explanation for observation patients hepatogenous jaundice, steroids often lower serum level.