Hemoglobin uptake by rat hepatocytes and its breakdown within lysosomes.
The peroxidatic activity of hemoglobin permitted visualization of its uptake by rat hepatocytes by means of the Graham-Karnovsky 3,3'-diaminobenzidine (DAB) procedure. Lysosomes were visualized by their acid phosphatase, beta-glucuronidase, and glucosaminidase activities. When large doses of rat, cow, or human hemoglobin are intravenously injected, or when hemoglobinemia is induced by injection of distilled water, DAB-positive hemoglobin is engulfed by pinocytosis. Pinocytotic vacuoles become digestive vacuoles ("phagolysosomes") by fusion with lysosomes of the dense body type that have moved from their pericanalicular position. By 16-24 hr after even massive amounts of hemoglobin (400 mg/100 g), the protein is barely demonstrable in hepatocytes. At the lowest doses of injected hemoglobin (15 mg/100 g body weight), DAB-positive vacuoles are demonstrable only in the Kupffer cells.
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D002417:Cattle; D005964:Glucosyltransferases / Q000378:metabolism; D005966:Glucuronidase / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D006486:Hemosiderosis / Q000473:pathology; D006801:Humans; D007275:Injections, Intravenous; D008099:Liver / Q000378:metabolism*; D008107:Liver Diseases / Q000473:pathology; D008247:Lysosomes / Q000201:enzymology / Q000378:metabolism*; D008854:Microscopy, Electron; D010544:Peroxidases; D010873:Pinocytosis; D051381:Rats; D013997:Time Factors
D006454:Hemoglobins; D010544:Peroxidases; D005964:Glucosyltransferases; D000135:Acid Phosphatase; D005966:Glucuronidase