EFFECTS OF X RAYS ON THE RIBONUCLEIC ACID OF HELA CELLS

Journal Article · Fri Nov 01 04:00:00 EST 1963 · Arch. Intern. Physiol. Biochim.

OSTI ID:4024704

Boudnitskaya, E V; Brunfaut, M; Errera, M

Hela cells were irradiated before or after incubation in the presence of cytidine-/sup 3/H and studied autoradiographically. The radioactivity was found in the RNA (80%) and DNA (20%). lf previously labeled (during 10 or 60 min or 24 hr) cells are irradiated and fixed, in the case of 10-min incubation 100 r decreases nucleolusradioactivity by 20 to 25%, 300 r causes a loss of 40% of activity in the nucleolus and 30% in the rest of the nucleus, and 900 r cause a loss of 60% in the nucleolus and 50% in the remainder of the nucleus. Increasing the incubation time decreases the loss of activity on irradiation; those varieties of RNA which are labeled easily are the most radiosensitive. If the incorporation of cytidine in 10 minutes into irradiated cells is studied, 100 r decreases incorporation in the nucleus (including the nucleolus) by 40%, 300 r by 70%, 900 r by the same amount. Prolonged (1- or 4-hr) incubation causes the decrease to be 25 and 35% for 300- and 900-r doses. For a relatively short period after irradiation, biosynthesis of RNA is retarded. In studies of nuclear RNA radioactivity transfer to cytoplasmic RNA, cells were labeled for 1 hr, then immediately irradiated and incubated in a nonradioactive medium for 4 hr before being fixed. After 100 r, cytoplasmic activity was decreased by 10%; after 300 r, by 40%; after 900 r, by 70%. The greatest part of cytoplasmic RNA is constituted by the ribosomes, and this observation indicates an inhibition of the renewed formation of these. (BBB)

• Research Organization: Universite, Brussels
• NSA Number: NSA-18-019599
• OSTI ID: 4024704
• Journal Information: Arch. Intern. Physiol. Biochim., Journal Name: Arch. Intern. Physiol. Biochim. Vol. Vol: 71
• Country of Publication: Country unknown/Code not available
• Language: French

Related Subjects

ANIMAL CELLS
BIOCHEMISTRY
BIOLOGY AND MEDICINE
CELL NUCLEI
DNA
HELA CELLS
IRRADIATION
LABELLED COMPOUNDS
MEASURED VALUES
METABOLISM
NUCLEIC ACIDS
NUMERICALS
ORGANIC NITROGEN COMPOUNDS
RADIATION DOSES
RADIATION EFFECTS
RADIOACTIVITY
RADIOAUTOGRAPHY
RADIOSENSITIVITY
RIBONUCLEIC ACID
TRITIUM
VARIATIONS
X RADIATION