Επίδρση της Ν.Ν.- Διμεθυλο - Νιτρωδοαμίνη στο μεταβολισμό του RNA σε ΜΥΕΣ C57BL

ADMINISTRATION OF A SINGLE DOSE OF THE HEPATOCARCINOGEN DIMETHYL-N- NITROSAMINETO MALE C57B1 MICE CAUSES AN INHIBITION OF HN-RNA SYNTHESIS. THE EXTENT OF THE INHIBITION DEPENDS ON THE DOSE ADIMINISTERED: THUS 4 HOURS AFTER THE ADMINISTRATION OF A DOSE OF 40MG/KG DIMETHYLNITROSAMINE, THE INHIBITION OF HNRNA SYNTHESIS REACHED 80%. IN CONTRAST, THE SAME DOSE CAUSED ONLY A 30% INHIBITION OF NUCLEOLAR RNA SYNTHESIS. THE MECHANISM OF THE INHIBITION OF HN-RNA SYNTHESIS WAS EXAMINED IN DETAIL. IN VIVO AND IN VITRO TRANSCRIPTION STUDIES INDICATED THAT IT WAS NOT DUE TO A DECREASE IN THE ACTIVITIES OF RNA POLYMERASES I AND IIOR AN ALTERATION IN THEIR BINDING TO CHROMATIN, BUT TO A REDUCED ACTIVITY OF CHROMATIN AS A TEMPLATE FOR TRANSCRIPTION. FURTHERMORE, THE DISAPPEARANCE OF HN-RNA FROM THE NUCLEUS IS NOT SIGNIFICANTLY AFFECTED BY THE NITROSAMINE. IN VITRO TRANSCRIPTION OF RNA ISOLATED FROM THE LIVERS OF CARCINOGEN TREATED ANIMALS DOES NOT APPEAR TO BE ALTERED RELATIVE TO CONTROL. CONSEQUENTLY IT IS CONCLUDED THAT THE INHIBITION OF HN-RNA SYNTHESIS IS DUE TO A FUNCTIONAL DAMAGE OF CHROMATIN. IN DETAIL THE MECHANISM OF THE INHIBITION OF NUCLEOLAR RNA SYNTHESIS WAS NOT EXAMINED. IT IS POSSIBLE THAT IT MAY BE RELATED TO THE INHIBITION OFPROTEIN SYNTHESIS WHICH DIMETHYLNITROSAMINE IS KNOWN TO CAUSE. APART FROM THEINHIBITION IN THE SYNTHESIS OF NUCLEOLAR RNA, THE APPEARANCE IN THE CYTOPLASMOF ITS MATURE PRODUCTS (RRNA) WAS FOUND TO BE EXTENSIVELY INHIBITED BY THE NITROSAMINE.

Grantor dc:publisher

National and Kapodistrian University of Athens

Year dc:date

1981

Authors dc:creator

• Garyfallidis, Stavros
• Γαρυφαλλίδης, Σταύρος

• RNA πολυμεράση
• RNA Σύνθεση
• Βιοχημεία
• Διμεθυλονιτροζοαμίνη
• Επίδραση καρκινογόνων
• Dimethynitrozamine
• Effect of carcinogens
• RNA Polymerase
• RNA Synthesis
• Φυσικές Επιστήμες
• Βιολογία
• Natural Sciences
• Biological Sciences

Language dc:language

gre

Identifier

10.12681/eadd/0266

OAI identifier oai:identifier

oai:10442/0266