Biomaterial Database

The mechanism of bilirubin-photosensitized DNA strand breakage in human cells exposed to phototherapy light. 1983

B S Rosenstein, and J M Ducore, and S W Cummings

Exposure of normal human fibroblasts to visible light (420-490 nm) in the presence of exogenously added 1-100 micrograms/ml bilirubin enhanced the level of DNA strand breakage compared with cells irradiated in the absence of added bilirubin. Treatment of cells in the dark with an irradiated bilirubin solution also induced DNA strand breaks. However, strand breakage was not detected in cells treated with an irradiated bilirubin solution that had been incubated with catalase (H2O2: H2O2 oxidoreductase EC 1.11.1.6). Examination of irradiated bilirubin solutions demonstrated the presence of hydrogen peroxide although, apparently, not at concentrations sufficient to account for the level of DNA strand breakage detected. Hence, irradiation of bilirubin results in the generation of hydrogen peroxide and possibly other peroxides that can cause DNA damage.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010545	Peroxides	A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)	Peroxide
D010789	Phototherapy	Treatment of disease by exposure to light, especially by variously concentrated light rays or specific wavelengths.	Blue Light Therapy,Blue-light Therapy,Light Therapy,Photoradiation Therapy,Red Light Phototherapy,Therapy, Photoradiation,Blue Light Therapies,Blue-light Therapies,Light Phototherapies, Red,Light Phototherapy, Red,Light Therapies,Light Therapies, Blue,Light Therapy, Blue,Photoradiation Therapies,Phototherapies,Phototherapies, Red Light,Phototherapy, Red Light,Red Light Phototherapies,Therapies, Blue Light,Therapies, Blue-light,Therapies, Light,Therapies, Photoradiation,Therapy, Blue Light,Therapy, Blue-light,Therapy, Light
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001663	Bilirubin	A bile pigment that is a degradation product of HEME.	Bilirubin IX alpha,Bilirubin, (15E)-Isomer,Bilirubin, (4E)-Isomer,Bilirubin, (4E,15E)-Isomer,Bilirubin, Calcium Salt,Bilirubin, Disodium Salt,Bilirubin, Monosodium Salt,Calcium Bilirubinate,Hematoidin,delta-Bilirubin,Bilirubinate, Calcium,Calcium Salt Bilirubin,Disodium Salt Bilirubin,Monosodium Salt Bilirubin,Salt Bilirubin, Calcium,delta Bilirubin