Methotrexate as a photosensitiser.
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.
Pascu
Mihail Lucian
ML
National Institute for Lasers, Plasma and Radiation Physics, Laser Department, P. O. Box MG-36, Bucharest - Magurele, Romania. mpascu@cost.esf.org
Staicu
Angela
A
Voicu
Letitia
L
Brezeanu
Mihail
M
Carstocea
Benone
B
Pascu
Ruxandra
R
Gazdaru
Doina
D
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
D017319:Photosensitizing Agents; D008727:Methotrexate