Phototoxicity Of Rhodamine Dyes

Shea, Christopher R.; Chen, Norah; Hasan, Tayyaba

doi:10.1117/12.960184

Cited by 13 publications

(18 citation statements)

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“…When the known (20,21,28) 1 O 2 generators TBRB and Rho 123 (10 M) were photoactivated, the fluorescence of both 1 O 2 detector molecules, 1,3-diphenylisobenzofuran (5 M) and 9,10-diphenylanthracene (5 M), was markedly quenched (data not shown). Very surprisingly, TMRM, for which 1 O 2 generation has not yet been quantified, was even more effective than Rho 123, presumably because of the small 1 O 2 quantum yield of the latter (20,28).…”

Section: Oxidation Of Nad(p)h Bymentioning

confidence: 99%

“…Very surprisingly, TMRM, for which 1 O 2 generation has not yet been quantified, was even more effective than Rho 123, presumably because of the small 1 O 2 quantum yield of the latter (20,28). Using TMRM, the fluorescence of 1,3-diphenylisobenzofuran was quenched more strongly (54.5 Ϯ 3.0%) than that of 9,10-diphenylanthracene (14.1 Ϯ 1.0%), in line with their rate constants for single electron transfer to 1 (29)).…”

Section: Oxidation Of Nad(p)h Bymentioning

confidence: 99%

“…This presumption is supported by the fact that after photoactivation of low concentrations of Rho 123 or TBRB, which had no significant effect on NAD(P)H redox state, almost no toxic effects became apparent within 60 min. The lack of a NAD(P)H oxidizing effect of both dyes under these conditions is likely to reflect either the low 1 O 2 quantum yield of Rho 123 (20,28) or the weak cellular uptake and predominantly cytosolic/lysosomal localization of TBRB. Although the photochemical effects observed here will inevitably differ with cell type, for instance high phototoxicity of Rho 123 and especially TBRB has been convincingly demonstrated for MGH-U1 bladder carcinoma cells (20,21), the data presented here should have implications for photochemotherapy.…”

Section: Mitochondrial Nad(p)h Depletion As a Decisive Trigger Of Apomentioning

confidence: 99%

“…The lack of a NAD(P)H oxidizing effect of both dyes under these conditions is likely to reflect either the low 1 O 2 quantum yield of Rho 123 (20,28) or the weak cellular uptake and predominantly cytosolic/lysosomal localization of TBRB. Although the photochemical effects observed here will inevitably differ with cell type, for instance high phototoxicity of Rho 123 and especially TBRB has been convincingly demonstrated for MGH-U1 bladder carcinoma cells (20,21), the data presented here should have implications for photochemotherapy. The effective generation of 1 O 2 in close proximity to the main pool of cellular NAD(P)H by using a photosensitizer with a high 1 O 2 quantum yield should improve the photochemotherapeutic potential of cancer treatment and diminish side effects because of the effective destruction of the antioxidative network of the targeted cells.…”

Section: Mitochondrial Nad(p)h Depletion As a Decisive Trigger Of Apomentioning

confidence: 99%

“…After establishing NAD(P)H baseline fluorescence (6 -10 min), the intracellular rhodamine derivatives were photoactivated for 1-60 s at the wavelengths cited above, and NAD(P)H fluorescence measurements were continued without delaying the interval for data collection. Rho 123 was excited at either 488 Ϯ 10 nm or 535 Ϯ 17.5 nm as the excitation maximum of this dye has been reported to shift from 507 (19) to 514.5 nm within cells (20,21). …”

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confidence: 99%

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NAD(P)H, a Primary Target of 1O2 in Mitochondria of Intact Cells

Petrat

Pindiur

Kirsch

et al. 2003

Journal of Biological Chemistry

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Direct reaction of NAD(P)H with oxidants like singlet oxygen ( 1 O 2 ) has not yet been demonstrated in biological systems. We therefore chose different rhodamine derivatives (tetramethylrhodamine methyl ester, TMRM; 2,4,5,7-tetrabromorhodamine 123 bromide; and rhodamine 123; Rho 123) to selectively generate singlet oxygen within the NAD(P)H-rich mitochondrial matrix of cultured hepatocytes. In a cell-free system, photoactivation of all of these dyes led to the formation of 1 O 2 , which readily oxidized NAD(P)H to NAD(P)؉ . In hepatocytes loaded with the various dyes only TMRM and Rho 123 proved suited to generating 1 O 2 within the mitochondrial matrix space. Photoactivation of the intracellular dyes (TMRM for 5-10 s, Rho 123 for 60 s) led to a significant (29.6 ؎ 8.2 and 30.2 ؎ 5.2%) and rapid decrease in mitochondrial NAD(P)H fluorescence followed by a slow reincrease. Prolonged photoactivation (>15 s) of TMRMloaded cells resulted in even stronger NAD(P)H oxidation, the rapid onset of mitochondrial permeability transition, and apoptotic cell death. These results demonstrate that NAD(P)H is the primary target for 1 O 2 in hepatocyte mitochondria. Thus NAD(P)H may operate directly as an intracellular antioxidant, as long as it is regenerated. At cell-injurious concentrations of the oxidant, however, NAD(P)H depletion may be the event that triggers cell death.Pyridine nucleotides, i.e. NAD(H) and NADP(H), play a central role in metabolism; they are the most important coenzymes acting as hydride (hydrogen anion) donors of various cellular dehydrogenases (e.g. glutathione reductase), functioning as reducing/oxidizing equivalents in essential reactions such as energy supply (aerobic or anaerobic) and photosynthesis, and are required for DNA repair.The ability of an organism to counteract reactive oxygen species (ROS) 1 or reactive nitrogen species depends on its antioxidative capabilities, which involves destroying of both prooxidants (e.g. ROOH, H 2 O 2 , ONOOH) and oxidants (e.g. radicals and reactive intermediates like singlet oxygen, 1 O 2 ). Whereas pro-oxidants are typically degraded by enzymes (e.g. catalase, glutathione peroxidase, and superoxide dismutase), oxidants are scavenged by relatively small biomolecules (e.g. ascorbic acid, glutathione, and ␣-tocopherol); these are termed directly operating antioxidants. In this context, NAD(P)H is crucial to maintaining the cellular redox state and/or antioxidative capacity, because of its essential role as a coenzyme in the enzymatic re-reduction of directly operating antioxidants (1, 2). Consequently, NAD(P)H deficiencies are linked with an increased sensitivity to oxidative stress (2, 3).The capability of NAD(P)H to additionally act as a directly operating antioxidant, i.e. to donate only one electron, was sharply underestimated by various biochemical researchers, a fact that is probably because of the observation that a biochemical standard one-electron oxidant, [Fe(CN) The H 2 O 2 -consuming enzymes catalase and glutathione peroxidase (GPx) strongly limi...

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Section: Oxidation Of Nad(p)h Bymentioning

confidence: 99%

Section: Oxidation Of Nad(p)h Bymentioning

confidence: 99%

Section: Mitochondrial Nad(p)h Depletion As a Decisive Trigger Of Apomentioning

confidence: 99%

Section: Mitochondrial Nad(p)h Depletion As a Decisive Trigger Of Apomentioning

confidence: 99%

mentioning

confidence: 99%

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NAD(P)H, a Primary Target of 1O2 in Mitochondria of Intact Cells

Petrat

Pindiur

Kirsch

et al. 2003

Journal of Biological Chemistry

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Dynamic aspects of rhodamine dye photosensitization in vitro with an argon‐ion Laser

Shea¹,

Chen²,

Hasan³

1989

Lasers Surg Med

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Phototoxicity in cultured human bladder carcinoma cells treated by 514.5-nm argon-ion laser irradiation plus rhodamine-123 (R123) or tetrabromo-R123 (TBR) was assessed counting total cell number and percent viability at 1, 24, 48, 72, and 96 h after irradiation. TBR was markedly more efficient than R123 at causing both reversible and persistent phototoxic cytostasis. Furthermore, TBR photosensitization caused net cytocidal effects at 0.5 J/cm2, which were not seen with R123 photosensitization at up to 40 J/cm2. The reduced phototoxic efficiency of R123 as compared to TBR appears, in part, to reflect the presence of a fraction of cells refractory to R123 photosensitization.

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Photodynamie activity on human larynx epidermoid carcinoma cell line, HEp-2

Ganesan

Masitamani

1994

Med Oncol

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Phototoxicity Of Rhodamine Dyes

Cited by 13 publications

References 0 publications

NAD(P)H, a Primary Target of 1O2 in Mitochondria of Intact Cells

NAD(P)H, a Primary Target of 1O2 in Mitochondria of Intact Cells

Dynamic aspects of rhodamine dye photosensitization in vitro with an argon‐ion Laser

Photodynamie activity on human larynx epidermoid carcinoma cell line, HEp-2

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