Erythrocyte Catabolism by Macrophages In Vitro THE EFFECT OF HYDROCORTISONE ON ERYTHROPHAGOCYTOSIS AND ON THE INDUCTION OF HEME OXYGENASE
AUTOR(ES)
Gemsa, Diethard
RESUMO
Phagocytosis of erythrocytes was studied in vitro in an incubation system consisting of rat peritoneal macrophages and antibody-coated 59Fe-labeled erythrocytes. The system was characterized in terms of the rate and magnitude of erythrophagocytosis, determined by the interiorization of the 59Fe label. On incubation of 150 × 106 macrophages with 75 × 106 antibodycoated erythrocytes, erythrophagocytosis began within a few minutes and was essentially completed after 2 h when 50% of the offered red cells had been ingested by the macrophages. Heme oxygenase (HO) activity, which is very low in native macrophages, increased 4- to 10- fold in response to the ingested erythrocytes; this enzyme stimulation occurred with a delay of 3 h in relation to erythrophagocytosis. Actinomycin D or puromycin prevented the increase of HO activity without affecting erythrophagocytosis, which suggests that the enzyme stimulation was due to substrate-mediated enzyme induction.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=302328Documentos Relacionados
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