title: Methotrexate as a photosensitiser.
abstract: The absorption, excitation and emission spectra of methotrexate (MTX) solutions in natural saline water and sodium hydroxide at 10(-4)-10(-5) MpH=8.4 were measured, while they were exposed to coherent and uncoherent visible and near ultraviolet (UV) light. Xe and Hg lamp and also a nitrogen pulsed laser radiation were used. The absorption spectra exhibited spectral bands between 225 nm and 450 nm. The 200 nm - 500 nm excitation spectra were measured with emission centred on 470 nm; fluorescence excitation was observed at 340 nm and 370 nm; emission fluorescence was detected between 400 nm and 600 nm, showing a maximum at 470 nm. Spectra modifications, non-linearly depending on exposure time (varying from 3 min to 180 min), indicated the photodissociation of MTX to the fluorescent compound 2,4 diamino-formylpteridine. In a preliminary in vivo experiment, rapid destruction of neovascularisation was observed in the MTX-impregnated conjunctive of the rabbit eye exposed to uncoherent UV and visible light.
authors.affiliation: National Institute for Lasers, Plasma and Radiation Physics, Laser Department, P. O. Box MG-36, Bucharest - Magurele, Romania. mpascu@cost.esf.org
authors.forename: Mihail Lucian
authors.initials: ML
authors.lastname: Pascu
authors.forename: Angela
authors.initials: A
authors.lastname: Staicu
authors.forename: Letitia
authors.initials: L
authors.lastname: Voicu
authors.forename: Mihail
authors.initials: M
authors.lastname: Brezeanu
authors.forename: Benone
authors.initials: B
authors.lastname: Carstocea
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Pascu
authors.forename: Doina
authors.initials: D
authors.lastname: Gazdaru
mesh_terms: D000818:Animals; D005123:Eye / Q000098:blood supply; D008727:Methotrexate / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000528:radiation effects; D010777:Photochemistry; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: D017319:Photosensitizing Agents; D008727:Methotrexate