Biomaterial Database

DNA damage in intact cells induced by bacterial metabolites of chloramphenicol. 1988

M Isildar, and J J Jimenez, and G K Arimura, and A A Yunis

Department of Medicine, University of Miami School of Medicine, FL 33101.

Four chloramphenicol (CAP) metabolites known to be produced by intestinal bacteria were examined with respect to their capacity to induce DNA damage in intact cells. The induction of DNA single-strand breaks in Raji cells, activated human lymphocytes, and human marrow cells was assayed by the alkaline elution technique. One of the four compounds tested, dehydro-CAP, was capable of inducing DNA single-strand breaks in all three cell systems at concentrations of 10(-4) M. This effect is comparable to that observed previously with nitroso-CAP, the nitroreduction intermediate of CAP. The nitroreduction of dehydro-CAP by human bone marrow cell homogenate was detected by the production of the corresponding amino derivative amounting to 5.6 X 10(-5) M from 2 X 10(-3) M substrate under aerobic conditions. In sharp contrast, nitroreduction of CAP by bone marrow could not be demonstrated. The genotoxicity of dehydro-CAP, its relative stability compared to the nitroso-CAP, and its nitroreducibility by bone marrow suggest that this bacterial metabolite of CAP may play a key role as a mediator of aplastic anemia in the predisposed host.

UI	MeSH Term	Description	Entries
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D009247	NADH, NADPH Oxidoreductases	A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.	Oxidoreductases, NADH, NADPH,NADPH Oxidoreductases NADH,Oxidoreductases NADH, NADPH
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D001853	Bone Marrow	The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.	Marrow,Red Marrow,Yellow Marrow,Marrow, Bone,Marrow, Red,Marrow, Yellow
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002701	Chloramphenicol	An antibiotic first isolated from cultures of Streptomyces venequelae in 1947 but now produced synthetically. It has a relatively simple structure and was the first broad-spectrum antibiotic to be discovered. It acts by interfering with bacterial protein synthesis and is mainly bacteriostatic. (From Martindale, The Extra Pharmacopoeia, 29th ed, p106)	Cloranfenicol,Kloramfenikol,Levomycetin,Amphenicol,Amphenicols,Chlornitromycin,Chlorocid,Chloromycetin,Detreomycin,Ophthochlor,Syntomycin
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004755	Enterobacteriaceae	A family of gram-negative, facultatively anaerobic, rod-shaped bacteria that do not form endospores. Its organisms are distributed worldwide with some being saprophytes and others being plant and animal parasites. Many species are of considerable economic importance due to their pathogenic effects on agriculture and livestock.	Coliform Bacilli,Enterobacteria,Ewingella,Leclercia,Paracolobactrum,Sodalis
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man