Original scientific paper
Autoradiographic studies of 3h-uridine uptake by human cells in tissue culture treated with puromycin (puro and pan) and x-radiation
Yvette Škreb
; Institute for Medical Research and Occupational Health, Yugoslav Academy of Sciences and Arts, Zagreb, Yugoslavia
Ljerka Radešić
; Institute for Medical Research and Occupational Health, Yugoslav Academy of Sciences and Arts, Zagreb, Yugoslavia
Jadranka Račić
; Institute for Medical Research and Occupational Health, Yugoslav Academy of Sciences and Arts, Zagreb, Yugoslavia
Abstract
The effect of X rays, puromycin dihydrochloride (Puro) and puromycin aminonucleoside (Pan) was studied on HeLa cells growing asynchronously. In one group, the cells were submitted to a single treatment: they were irradiated with 300 rads X rays or incubated for 2 hours in a nutrient medium supplemented with Puro (50 µg/ml) or Pan (10 µg/ml). In the second group the irradiated cells were submitted to a post or pretreatment with Puro or Pan in the same conditions. To evaluate the effect, the survival and RNA synthesis were used as parameters. Besides examination of colony forming ability, autoradiographic experiments related to the 3H-uridine uptake were performed. Regarding the survival, it can be seen that when the agents are applied separately, they produce different effects, those of X rays being more drastic and of Pan less so. In post or pretreatment, Puro enhances the effect of X rays while Pan diminishes it. When applied separately or successively, the three agents produced a similar inhibition of 3H-uridine uptake in the nucleoli. In the nucleoplasm and the cytoplasm, the three agents applied separately produced the same kind of effect, the depression caused by Puro being slightly higher. In the case of double treatments, the inhibitory effect of Puro did not add to that of radiation which was only enhanced. Pan which also reduces the 8H-uridine uptake in the nucleoplasm and cytoplasm when applied alone, given after or before irradiation prevents to a large extent the X-ray inhibition so that the final labelling is very high. It can be concluded that applied before or after X irradiation Puro does not affect significantly the survival and RNA synthesis, Pan significantly improves both the survival and RNA synthesis (apart from the nucleoli) in the same conditions. This differential effect seems to be due to a particular effect on the synthesis of proteins especially those involved in the repair mechanisms.
Keywords
Hrčak ID:
167272
URI
Publication date:
19.6.1975.
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