Autoradiografski studij inkorporacije 3h-uridina u ljudskim stanicama u kulturi kada su tretirane puromicinom (puro i pan) prije ili poslije rendgenskog zračenja

Autor: Y, Skreb, L, Radesić, J, Racić
Jazyk: angličtina
Rok vydání: 1975
Předmět:
Zdroj: Arhiv za higijenu rada i toksikologiju
Volume 26
Issue 1
ISSN: 1848-6312
0004-1254
Popis: 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.
Cilj rada bio je proučavanje posljedica jednokratnog djelovanja puromicina na HeLa stanice u asinkronoj kulturi, prije ili poslije rendgenskog zračenja. Za zračenje stanica upotrijebili smo dozu od 300 rada. Koncentracija puromicina kojima su stanice bile izvrgnute tijekom 2 sata bile su za dihidroklorid puromicina (Puro) 50 µg/ml a za aminonukleozid puromicina (Pan) 10 µg/ml. Kao parametri za evaluaciju djelovanja nabrojenih agensa poslužili su nam preživljavanje stanica i sinteza RNA. Pored sposobnosti formiranja kolonija autoradiografskom smo metodom pratili sintezu RNA ugrađivanjem specifično obilježenog prekursora 3H-uridina. Radioaktivni tragovi su brojeni ne samo u cijelim stanicama svake skupine, nego posebno u nukleolima, nukleoplazmi i citoplazmi. Što se tiče preživljavanja, može se uočiti da agensi, aplicirani odvojeno, imaju različit učinak: rendgensko zračenje djeluje najjače, a Pan najslabije. U nukleolima svaki od postupaka uzrokuje sličan inhibitorni učinak na inkorporaciju 3H-uridina (50%). Dok Pura izaziva isti stupanj inhibicije (50%) u cijeloj stanici, Pan pospješuje inkorporaciju 3H-uridina u nukleoplazmi i citoplazrni ozračene stanice u takvoj mjeri da je sinteza RNA gotovo normalna. Iz dobivenih rezultata može se zaključiti da Pura apliciran prije ili poslije zračenja ne mijenja bitno preživljavanje stanica niti RNA sintezu. Pod istim uvjetima Pan povećava preživljavanje i RNA sintezu gotovo do normale (osim u nukleolima). Čini se da razlike između djelovanja Puro i Pan leže u diferencijalnom efektu na jednu od funkcija DNA, sto indirektno utječe na enzime potrebne za uključivanje reparatornih mehanizama.
Databáze: OpenAIRE
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