Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spleen cell suspensions from AKR and CD-1 mice contain peroxidase activity as determined by guaiacol oxidation. This activity is found predominately in the 20,000 x g pellet fraction of spleen cell homogenates. In the presence of H(2)O(2) and chloride ion at acidic pH, splenic peroxidase mediates the oxidation of d- or l-alanine to CO(2), NH(3), and acetaldehyde. The same reaction mixture without added amino acid can kill both gram-positive and gram-negative bacteria. The conditions for both reactions are similar. Both have an absolute requirement for H(2)O(2) and chloride ion, neither is active at neutral or alkaline pH, and both are inhibited by the sulfonic amino acid taurine. In these aspects, splenic peroxidase is qualitatively similar in its activity to myeloperoxidase (MPO) from polymorphonuclear leukocytes. It is quantitatively different from MPO in that the latter is more potent on a per guaiacol unit basis with respect to both amino acid oxidation and bactericidal activity. Still another quantitative difference is that splenic peroxidase requires 0.1 m NaCl for activity, whereas MPO functions with as little as 0.005 m NaCl. Splenic peroxidase and MPO both appear to differ qualitatively from horseradish peroxidase in that the latter enzyme does not mediate amino acid oxidation.
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PMID:Mouse splenic peroxidase and its role in bactericidal activity. 463 63

The effects of alcohol on bone marrow are not well understood. We measured the influence of ethanol and its metabolite, acetaldehyde, on the in vitro proliferation of hematopoietic progenitor cells from mice and human beings. Colony formation by both early and late erythroid progenitor cells was suppressed by concentrations of ethanol (0.05 to 0.2 per cent) that are easily achieved in vivo. The corresponding suppressing concentration of acetaldehyde was 0.001 per cent. In contrast, suppression of granulocyte/macrophage progenitor cells required 3.0 per cent ethanol or 0.03 per cent acetaldehyde. Spleen colony formation by pluripotent stem cells was resistant to concentrations of ethanol and acetaldehyde that suppressed in vitro colony formation of committed myeloid and erythroid progenitor cells by 50 per cent. The suppression of both myeloid and erythroid colony formation was partially reversed by supplementing the cultures with folinic acid or pyridoxine. These data provide an explanation for the preferential suppression of erythropoiesis observed clinically in ethanol abuse. They also suggest that acetaldehyde has a role in ethanol-mediated bone-marrow suppression.
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PMID:Suppression of hematopoietic-progenitor-cell proliferation by ethanol and acetaldehyde. 711 Feb 59