scholarly journals Increased synthesis of low-molecular-weight nuclear ribonucleic acids of rat liver after γ irradiation and hepatectomy

1975 ◽  
Vol 146 (2) ◽  
pp. 357-360 ◽  
Author(s):  
A Fónagy ◽  
E J Hidvégi
Keyword(s):  
Molecular Weight ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Orotic Acid ◽  
Low Molecular Weight ◽  
Polyacrylamide Gels ◽  
Γ Irradiation ◽  
Ribonucleic Acids

Incorporation of [3H]orotic acid into low-molecular-weight nRNA of rat liver, fractionated on polyacrylamide gels, increased 6-12h after partial hepatectomy and 6h after γ-irridation at 2000 R. The incorporation of orotic acid was particularly increased into the 4.5S, 5S and approx. 10S nRNA fractions. If the irradiation was given after 6h of regeneration and RNA was isolated from the nucleus 12h after hepatectomy then the incorporation of orotic acid into these low-molecular-weight nRNA components was greater than after hepatectomy or irradiation alone.

scholarly journals Effects of γ-irradiation on biosynthesis of different types of ribonucleic acids in normal and regenerating rat liver

1975 ◽  
Vol 146 (1) ◽  
pp. 41-51 ◽  
Author(s):  
G G Markov ◽  
G N Dessev ◽  
G C Russev ◽  
R G Tsanev
Keyword(s):  
Partial Hepatectomy ◽  
Rat Liver ◽  
Cellular Response ◽  
Specific Radioactivity ◽  
Regenerating Liver ◽  
Γ Irradiation ◽  
Ribonucleic Acids ◽  
New Genes ◽  
Regenerating Rat Liver ◽  
Different Types

1. The effect of γ-irradiation (4000rd) on the synthesis of ribosomal (pre-rRNA) and heterogeneous nuclear RNA (pre-mRNA) in normal and in regenerating rat liver was studied by using 40 min labelling with [6(-14)C]orotic acid. 2. Partial hepatectomy caused a sharp transient increase in the specific radioactivity of the endogenous low-molecular-weight RNA precursors in the livers of both normal and irradiated rats. Irradiation of intact animals did not affect the pool. 3. Irradiation enhanced the synthesis of pre-rRNA for at least 12h. The synthesis of pre-mRNA was also enhanced, but only in the first 3h after irradiation. 4. Partial hepatectomy strongly stimulated the synthesis of both pre-rRNA and pre-mRNA. 5. The synthesis of pre-rRNA was enhanced also in regenerating liver of animals irradiated before or after the operation. The conclusion can be drawn that the early increase in the synthesis of ribosomal RNA is a non-specific cellular response to different injuring factors. 6. The only case where irradiation caused an early inhibition of RNA synthesis was that of pre-mRNA in regenerating liver. This supports the hypothesis that ionizing radiation does not suppress the transcription per se but affects the mechanisms of activation of new genes (cellular programming).

Biosynthesis of the Low Molecular Weight Carrier Protein for Insulin-Like Growth Factors in Rat Liver and Fibroblasts*

Endocrinology ◽  
1987 ◽  
Vol 121 (3) ◽  
pp. 1041-1050 ◽  
Author(s):  
JOYCE A. ROMANUS ◽  
YVONNE W.-H. YANG ◽  
S. PETER NISSLEY ◽  
MATTHEW M. RECHLER
Keyword(s):  
Molecular Weight ◽  
Growth Factors ◽  
Rat Liver ◽  
Low Molecular Weight ◽  
Carrier Protein ◽  
Insulin Like Growth Factors
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