title: Bone marrow: its contribution to heme catabolism.
abstract: Heme oxygenase (HO) and biliverdin reductase (BR), the two NADPH-dependent enzymes involved in the degradation of hemoglobin and its derivatives, were measured in bone marrow aspirates from 5 hematologically normal persons, 4 patients with chronic leucemia (CL), 11 patients with acute leucemia (AL), 8 patients with refractory sideroblastic anemia (RA), 7 patients with iron-deficiency anemia (IA), 5 patients with hemolytic anemia (HA), and 7 patients with secondary anemia (SA) to determine the enzymatic capacity of the bone marrow in different hematologic disorders for heme catabolism. HO activity in the bone marrow of normal persons was 0.42 +/- 0.28 (SD) nmoles bilirubin/10 mg protein/min; in CL, 2.15 +/- 1.34; in AL, 0.39 +/- 0.25; in RA, 0.58 +/- 0.37; in IA, 0.41 +/- 0.28; in HA, 2.56 +/- 1.40; and in SA, 1.72 +/- 1.06. BR activity, respectively, was in normal persons 8.7 +/- 2.4 (SD) nmoles bilirubin/10 mg protein/min; in CL, 13.6 +/- 9.1; in AL, 3.8 +/- 3.1 in RA, 5.1 +/- 2.7; in IA, 5.5 +/- 3.7; in HA, 17.0 +/- 7.2; and in SA, 10.5 +/- 4.2. On the basis of these findings it seems evident that both oxygenase and biliverdin reductase activities of the bone marrow are capable of adaptive regulation. The physiologic role of bone marrow in heme catabolism seems to be of significant importance.
mesh_terms: D000740:Anemia / Q000201:enzymology*; D000743:Anemia, Hemolytic / Q000201:enzymology; D000747:Anemia, Hypochromic / Q000201:enzymology; D000756:Anemia, Sideroblastic / Q000201:enzymology; D001664:Biliverdine / Q000378:metabolism; D001853:Bone Marrow / Q000201:enzymology*; D006418:Heme / Q000378:metabolism*; D006801:Humans; D007938:Leukemia / Q000201:enzymology*; D007951:Leukemia, Myeloid / Q000201:enzymology; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism*
chemical_list: D006418:Heme; D010105:Oxygenases; D009247:NADH, NADPH Oxidoreductases; D001664:Biliverdine