scholarly journals Effect of hypophysectomy on liver nuclear ribonucleic acid synthesis in aging rats

1979 ◽  
Vol 184 (3) ◽  
pp. 669-674 ◽  
Author(s):  
R Bolla ◽  
W D Denckla
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Hormone Replacement ◽  
Polymerase Activity ◽  
Sprague Dawley ◽  
Age Related ◽  
Nuclear Rna ◽  
Rna Polymerase Activity ◽  
Liver Nuclei ◽  
Intact Rats

Changes in RNA synthesis in liver nuclei were observed at different ages and after hypophysectomy and hormone replacement in female Sprague-Dawley rats. As determined by the incorporation of [3H]UMP into an acid-insoluble product, RNA synthesis decreased by about 75% in intact rats from 6 months to 24 months of age. This decline with age was not observed in liver nuclei from 24-month-old rats that had been hypophysectomized at 12 months and maintained on a minimal hormone-replacement therapy. Thyroid hormones and somatotropin (growth hormone) had an additive effect on RNA synthesis in liver nuclei from these hypophysectomized rats. The same hormones had no significant effect on intact, age-matched rats. With advancing age, nuclei of intact rats had an increase in the pool of free RNA polymerase and an apparent decrease in the enzyme activity bound to nuclear chromatin. There was no change in total enzyme with age. In hypophysectomized, hormone-treated rats, free RNA polymerase activity decreased and chromatin-bound activity increased. There was no difference in total nuclear RNA polymerase activity between operated or intact rats. However, the ratio of the bound to the free activity was different. These results suggest that the ability of RNA polymerase to bind to chromatin may be involved in the age-related decrease in liver nuclear RNA synthesis of intact rats.

scholarly journals Age-associated changes in initiation of ribonucleic acid synthesis in isolated rat liver nuclei

1980 ◽  
Vol 188 (1) ◽  
pp. 55-60 ◽  
Author(s):  
J K Miller ◽  
R Bolla ◽  
W D Denckla
Keyword(s):  
Rna Synthesis ◽  
Hormone Replacement ◽  
Age Groups ◽  
Acid Synthesis ◽  
Sprague Dawley ◽  
Age Related ◽  
Liver Nuclei ◽  
Old Rats ◽  
Insoluble Product ◽  
Intact Rats

Initiation of RNA synthesis was studied in an attempt to determine a possible molecular mechanism for age-related biochemical and physiological changes. Initiation of RNA synthesis was determined by incorporation of [gamma-32 P]ATP and of [gamma-32P]GTP into an acid-insoluble product by intact nuclei isolated from livers of Sprague-Dawley CD-strain rats of various ages. When the rats were grouped into young (0.75-9 months) and old (12-30 months) rats, a significant decrease (P less than or equal to 0.001) in incorporation of initiating nucleotides was observed. The rat population was divided into five age groups (0.75-3 months, 4-9 months, 12-18 months, 19-23 months and 30 months) for further analysis of the effect of age on the initiation of RNA synthesis. Analysis of data from these groups indicated a significant trend for an age-related decrease in RNA-synthesis initiation (correlation coefficient = 0.94). Long-term hypophysectomy coupled with minimal hormone-replacement therapy was shown to have a significant effect on the reversal of the age-related decrease in initiation of RNA synthesis. It was observed that initiation of RNA synthesis in nuclei from 19-month-old rats, hypophysectomized at 12 months of age, was closest to that in 3-month-old intact rats and was not significantly different from that in liver nuclei of 0.75-9-month-old intact rats.

scholarly journals RNA Polymerase Activity Assay on Biochips: Correlation between Template DNA Density and RNA Synthesis

2010 ◽  
Vol 31 (7) ◽  
pp. 2107-2109 ◽  
Author(s):  
Bok-Hui Lee ◽  
Hyun-Jung Seo ◽  
So-Hyun Kim ◽  
Woong Jung ◽  
Dong-Woon Kim ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Synthesis ◽  
Polymerase Activity ◽  
Activity Assay ◽  
Rna Polymerase Activity ◽  
Template Dna ◽  
Dna Density

scholarly journals COMPARISON AND CHARACTERIZATION OF NUCLEAR ISOLATION PROCEDURES AS APPLIED TO CHICK OVIDUCT

1973 ◽  
Vol 59 (3) ◽  
pp. 685-695 ◽  
Author(s):  
John T. Knowler ◽  
Harold L. Moses ◽  
Thomas C. Spelsberg
Keyword(s):  
Citric Acid ◽  
Rna Polymerase ◽  
Polymerase Activity ◽  
Isolation Procedure ◽  
High Yield ◽  
Rna Integrity ◽  
Nuclear Rna ◽  
Rna Polymerase Activity ◽  
Nuclear Isolation

A number of methods for the preparation of chick oviduct nuclei have been compared. Nuclei have been isolated in hypertonic sucrose and citric acid and the product has been characterized with respect to cleanliness, ultrastructure, RNA polymerase activity, RNA integrity, and chromatin composition. The study demonstrates that the choice of oviduct nuclear isolation procedure will depend markedly on the purpose for which the nuclei are required. Thus, nuclei prepared entirely in high-molarity sucrose retain the highest levels of RNA polymerase. Those prepared rapidly in the presence of citric acid retain nuclear RNA in an essentially undegraded state. Finally, a bulk preparation is described which, because of its adaptability and high yield of morphologically intact nuclei using large amounts of tissue, is ideal for use in preparing chromatin. Conditions are described by which isolated nuclei can be stored for up to 6 months and retain their morphology, chemical characteristics, and RNA polymerase activity.

Specificity and nature of the rapid steroid-stimulated increase in sertoli cell nuclear RNA polymerase activity

1982 ◽  
Vol 16 (5) ◽  
pp. 653-659 ◽  
Author(s):  
D.J. Lamb ◽  
J.R. Wagle ◽  
Y.H. Tsai ◽  
A.L. Lee ◽  
A. Steinbercer ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Sertoli Cell ◽  
Polymerase Activity ◽  
Nuclear Rna ◽  
Rna Polymerase Activity ◽  
Nuclear Rna Polymerase
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