Regenerative anemia

Reitter GS, Martland HS. 1926. Leucopenic anemia of the regenerative type due to exposure to radium and mesothorium Report of a case. Am J Roentgenol 16 161-166. 

Experimental data in animals and studies of human cases of benzene intoxication indicate a link between the decrease in bone marrow cellularity and the development of leukemia. Many cases of benzene-induced leukemia appear to have been preceded by aplastic anemia (Toft et al. 1982). The compensatory response (regenerative hyperplasia) observed in the bone marrow, thymus, and spleen of exposed animals may play a role in the carcinogenic response (Rozen and Snyder 1985 Snyder 1987 Snyder and Koscis 1975 Snyder etal. 1984). 

Enalapril-induced anemia has been reported in hemodialysis patients and in kidney transplant recipients. The anemia is usually normocytic, normochromic, and non-regenerative. Deficient bone-marrow eiythropoiesis has occasionally been described. The anemia is reversible after withdrawal. Although the hypothesized mechanism of a reduction in erythropoietin blood concentrations by enalapril is controversial, in a prospective controlled study enalapril increased recombinant human erythropoietin requirements to maintain hemoglobin concentrations (5). 

DAAB is a respiratory tract, skin, and eye irritant. DAAB yields benzene and aniline as metabolites. The proposed metabolic pathway for DAAB is that it is cleaved reductively by liver enzymes or gut flora to form aniline, benzene, and nitrogen. DAAB metabolism also results in the formation of a reactive phenyl radical, which could account for an additional risk of toxicity or carcinogenicity. The erythrocyte and lymphoid systems are major targets of DAAB toxicity. Induction of lymphoid atrophy of the thymus and other lymphoid tissues were observed, as well as methemoglobin formation, accompanying anemia, increased spleen weights, and regenerative hematopoiesis. 

Both male and female dogs ingesting 1,3-dichloropropene (15 mg kg day ) for either 13 weeks or 1 year exhibited primarily regenerative hypochromic, microcytic anemia. Chronic exposure via the oral route has also caused neoplastic and preneoplastic lesions of the stomach in rats. Hyperplasia and hyperkeratosis of the forestomach and urinary bladder hyperplasia were reported in mice exposed to one formulation of 1,3-dichloropropene (Telone Ilb) for 2 years through inhalation. 

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