[Electron microscopic studies of the effect of x-rays and L-3,4-dihydroxyphenylalanine (L-Dopa)--alone and in combination-- on Harding-Passey melanoma cells in monolayer cell culture].
Monolayer cultures of Harding-Passey melanoma cells in exponential growth phase were exposed to 8 or 16 Gy by X-ray treatment. The 8 Gy treated cells revealed little ultrastructural changes, while the 16 Gy exposed cells showed increased damage as segregates, swollen mitochondria and vacuoles. Sole treatment with L-3,4-dihydroxyphenylalanine (2 x 10(-4) M L-Dopa) resulted in insignificant electronmicroscopically tangible cell alterations. Combined treatment--starting with 8 Gy irradiation followed by a six-day incubation in the presence of 2 x 10(-4) M L-Dopa--revealed more pronounced cell damage with final cell disintegration; the cytoplasm contained an increased number of vacuoles and segregates, a strongly decreased endoplasmic reticulum as well as swollen mitochondria and less pinocytosis vesicles; the cell surface showed less microvilli. Melanin containing organelles increased after the combination treatment. The growth inhibitory and cell destructive influence of L-Dopa on X-ray pretreated melanogenic melanoma cells was explained with the formation of cytotoxic oxidation products of L-Dopa.
Proske
H
H
Klinik für Strahlentherapie, Philipps-Universität Marburg/Lahn.
Schachtschabel
D O
DO
Plamper
G
G
Paul
N
N
Pfab
R
R
D000818:Animals; D007980:Levodopa / Q000494:pharmacology*; D008546:Melanoma, Experimental / Q000473:pathology*; D051379:Mice; D008854:Microscopy, Electron; D014407:Tumor Cells, Cultured / Q000187:drug effects* / Q000528:radiation effects* / Q000648:ultrastructure
D007980:Levodopa
Elektronenmikroskopische Untersuchungen zur Wirkung von Röntgenstrahlen und L-3,4-Dihydroxyphenylalanin (L-Dopa)--allein und inKombination--auf Harding-Passey-Melanomzellen in Monolayerzellkultur.