Is rhodamine 123 a photosensitizer?
Because of conflicting reports on the photoxicity of rhodamine 123 (Rh 123), we have undertaken a study of Rh 123 photosensitization in several in vitro systems. First, Rh 123 is not a photodynamic agent and does not react with singlet oxygen. Second, when bound to cytochrome c (Cyt c), Rh 123 photosensitizes ferro Cyt c but not ferri Cyt c degradation by an oxygen-independent process. When delivered to skin fibroblasts where it specifically stains mitochondria, Rh 123 photosensitizes membrane damage. These results are consistent with the hypothesis that Rh 123 is a phototoxic stain. The lack of photosensitivity of Rh 123-stained mitochondria in some cell lines might therefore be due to specific structural features.
Morlière
P
P
Laboratoire de Dermatologie, INSERM U312, Hôpital Henri Mondor, Creteil, France.
Santus
R
R
Bazin
M
M
Kohen
E
E
Carillet
V
V
Bon
F
F
Rainasse
J
J
Dubertret
L
L
D000818:Animals; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000528:radiation effects; D007425:Intracellular Membranes / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D008928:Mitochondria / Q000187:drug effects / Q000528:radiation effects; D010100:Oxygen / Q000737:chemistry; D010778:Photochemotherapy; D020112:Rhodamine 123; D012235:Rhodamines / Q000494:pharmacology*; D026082:Singlet Oxygen; D013050:Spectrometry, Fluorescence
D012235:Rhodamines; D026082:Singlet Oxygen; D020112:Rhodamine 123; D010100:Oxygen