ULTRASTRUCTURAL EVIDENCE FOR THE STIMULATION OF NUCLEAR RIBONUCLEIC ACID SYNTHESIS BY OESTRADIOL-17β IN THE VAGINAL EPITHELIUM OF THE OVARIECTOMIZED MOUSE

1970 ◽  
Vol 47 (2) ◽  
pp. 143-NP ◽  
Author(s):  
IRINA POLLARD
Keyword(s):  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Control Level ◽  
Staining Technique ◽  
Acid Synthesis ◽  
Vaginal Epithelium ◽  
Ovariectomized Mouse ◽  
Ultrastructural Evidence ◽  
Stimulation Of

SUMMARY The cytochemical nature of the ultrastructural nucleolar transformation previously observed in the vaginal epithelium of the ovariectomized mouse after local application of oestradiol-17β was investigated using a recently developed ultrastructural staining technique. Oestradiol treatment induced ribonucleic acid (RNA) synthesis, especially in the nucleolus but also in the nuclear chromatic region and ribosomes. Actinomycin D administered simultaneously with oestradiol reduced the oestrogen-induced nucleolar response to the control level. These findings are discussed with special reference to the mode of action of oestrogens.

Hormone-induced differentiation of antheridial branches in Achlya ambisexualis: dependence on ribonucleic acid synthesis

1974 ◽  
Vol 20 (7) ◽  
pp. 977-980 ◽  
Author(s):  
David K. Horowitz ◽  
Peter J. Russell
Keyword(s):  
Sexual Differentiation ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Steroid Hormone ◽  
Acid Synthesis ◽  
Aquatic Fungus ◽  
Induced Differentiation ◽  
Sexual Steroid ◽  
Achlya Ambisexualis

Sexual differentiation in male strains of the aquatic fungus Achlya ambisexualis Raper is induced by antheridiol, a sexual steroid hormone secreted by female strains. Antheridiol-induced initiation of the morphologically distinct antheridial branches in male Achlya is completely prevented when DNA-dependent RNA synthesis is inhibited by actinomycin D. In addition antheridial branch elongation is inhibited to a degree proportional to the concentration of actinomycin D added. Thus, evidence indicates that RNA synthesis is required for antheridiol-induced initiation of antheridial branching and that continued RNA synthesis is required for elongation of antheridial branches.

scholarly journals Decreased ribonucleic acid synthesis in isolated rat liver nuclei during starvation

1970 ◽  
Vol 120 (2) ◽  
pp. 381-384 ◽  
Author(s):  
D. Rickwood ◽  
H. G. Klemperer
Keyword(s):  
Rna Polymerase ◽  
Ammonium Sulphate ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Isolated Nuclei ◽  
Isolated Rat Liver ◽  
Liver Nuclei ◽  
Isolated Rat

1. Isolated nuclei from starved rats showed a lowered incorporation of [14C]UMP into RNA. 2. The Mg2+-dependent incorporation was decreased by 30% after 1 day of starvation, but incorporation in the presence of Mn2+ and ammonium sulphate decreased only after longer periods of starvation. 3. RNA synthesis by nuclei in the presence of excess of added RNA polymerase was unchanged after 1 day of starvation and was inhibited by 20% after 4 days. 4. The capacity of nuclei to bind actinomycin D was unchanged after 1 day and was decreased by 20% after 4 days of starvation.

GIBBERELLIN, AS A REGULATOR OF PROTEIN AND RIBONUCLEIC ACID SYNTHESIS DURING SENESCENCE IN LEAF CELLS OF TARAXACUM OFFICINALE

1966 ◽  
Vol 44 (6) ◽  
pp. 739-745 ◽  
Author(s):  
R. A. Fletcher ◽  
Daphne J. Osborne
Keyword(s):  
Leaf Senescence ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Taraxacum Officinale ◽  
Leaf Discs ◽  
Protein And Rna Synthesis ◽  
Chlorophyll Protein ◽  
Gibberellin Treatment

The addition of gibberellin A3 (GA) to leaf discs of Taraxacum officinale Weber retards their senescence and delays the decline in the levels of chlorophyll, protein, and RNA. Incorporation of 14C leucine and 14C adenine into protein and RNA respectively was increased by GA. This enhancement of protein and RNA synthesis did not occur if the discs were supplied with actinomycin D before treatment with gibberellin. If, however, actinomycin D was added after the gibberellin treatment then the stimulatory effect of the hormone was maintained. These results suggest that the retarding action of gibberellins on leaf senescence could be mediated through a regulation of RNA synthesis that is DNA dependent.

scholarly journals Ribonucleic acid synthesis in porphyric rat liver induced by 3,5-dicarbethoxy-1,4-dihydrocollidine

1973 ◽  
Vol 136 (1) ◽  
pp. 209-215 ◽  
Author(s):  
Hajime Nawata ◽  
Kenichi Kato
Keyword(s):  
Rat Liver ◽  
Liver Cell ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Rapid Decrease ◽  
Aminolaevulinic Acid ◽  
Induction Mechanism

1. Administration of 3,5-dicarbethoxy-1,4-dihydrocollidine to rats caused a marked increase in the activity of δ-aminolaevulinic acid synthetase as well as a slight net increase in RNA in the livers. 2. 3,5-Dicarbethoxy-1,4-dihydrocollidine primarily stimulated the synthesis of RNA in the nucleus of the liver cell. 3. The decrease in RNA synthesis after administration of this drug resulted in a rapid decrease in the activity of this induced enzyme. This was also confirmed by treatment with actinomycin D. 4. From kinetic experiments on synthesis of RNA and δ-aminolaevulinic acid synthetase in vivo the induction mechanism of this enzyme was discussed.

scholarly journals Biosynthesis of growth hormone in the rat anterior pituitary gland. Stimulation of biosynthesis in vitro by insulin

1973 ◽  
Vol 134 (4) ◽  
pp. 1103-1113 ◽  
Author(s):  
A. Betteridge ◽  
M. Wallis
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Rna Synthesis ◽  
Glucose Utilization ◽  
Actinomycin D ◽  
Hormone Synthesis ◽  
Pituitary Glands ◽  
Hormone Biosynthesis ◽  
Stimulation Of

The effect of insulin on the incorporation of radioactive leucine into growth hormone was investigated by using rat anterior pituitary glands incubated in vitro. A 50% stimulation over control values was observed at insulin concentrations above 2μm (280munits/ml). The effect was specific for growth hormone biosynthesis, over the range 1–5μm-insulin (140–700munits/ml). Lower more physiological concentrations had no significant effect in this system. Above 10μm (1.4 units/ml) total protein synthesis was also increased. The stimulation of growth hormone synthesis could be partially blocked by the addition of actinomycin D, suggesting that RNA synthesis was involved. Insulin was found to stimulate the rate of glucose utilization in a similar way to growth hormone synthesis. 2-Deoxyglucose and phloridzin, which both prevented insulin from stimulating glucose utilization, also prevented the effect of insulin on growth hormone synthesis. If glucose was replaced by fructose in the medium, the effect of insulin on growth hormone synthesis was decreased. We conclude that the rate of utilization of glucose may be an important step in mediating the effect of insulin on growth hormone synthesis.

Activité génétique au cours de l'embryogenèse de l'Oligochète Eisenia fœtida (autoradiographie à l'uracile-3H et traitement à l'actinomycine D)

Development ◽  
1976 ◽  
Vol 35 (2) ◽  
pp. 403-424
Author(s):  
Par J. Devriès
Keyword(s):  
Ribonucleic Acid ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Eisenia Foetida ◽  
Messenger Rnas ◽  
Blastula Stage ◽  
Stages Of Development ◽  
Interphase Nuclei ◽  
Nuclear Membranes

Embryos of Eisenia fœtida (Spiralia) have been cultivated with [3H]uracil precursor of RNA at different stages of development from egg to gastrula. The results show that ribonucleic acid synthesis detected by autoradiography begins precociously. During segmentation messenger RNAs are produced by interphase nuclei and liberated in cytoplasm cyclically at mitosis. After the blastula stage rRNAs (nucleoli), which can migrate through the nuclear membranes, predominate. The blastomeres, which contain polar plasm and also mesoderm, already known for its controlling part in embryogenesis after gastrulation, are the seats of the increasingly important ribonucleic acid synthesis. These genetic transcriptions, which are inhibited by actinomycin D, are implicated in the determination of the blastomeres and postblastular differentiation. Only the messages required for the segmentation divisions pre-exist in the undivided egg.

STUDIES ON THE MECHANISM OF ACTION OF ANGIOTENSIN ON FLUID TRANSPORT BY THE MUCOSA OF RAT DISTAL COLON

1972 ◽  
Vol 54 (3) ◽  
pp. 483-492 ◽  
Author(s):  
N. T. DAVIES ◽  
K. A. MUNDAY ◽  
B. J. PARSONS
Keyword(s):  
Protein Synthesis ◽  
Cyclic Amp ◽  
Rna Synthesis ◽  
Fluid Transport ◽  
Actinomycin D ◽  
Distal Colon ◽  
Rat Colon ◽  
Colon Mucosa ◽  
Rat Distal Colon ◽  
Stimulation Of

SUMMARY A study was made of the effects of cyclic AMP, theophylline, cycloheximide, puromycin and actinomycin D on the stimulation by angiotensin of fluid transport by sacs of rat colon mucosa. Cyclic AMP and theophylline, added together or separately, had no effect on fluid transport by colon sacs, suggesting that the stimulation of fluid transport after the application of angiotensin is not mediated through cyclic AMP. Cycloheximide and puromycin (used at concentrations which block colon protein synthesis by 50–90%) had no effect on fluid transport by control colon sacs, but completely blocked the stimulatory response of the colon to angiotensin. In contrast, actinomycin D (at a concentration which significantly inhibits RNA synthesis) did not affect fluid transport in control or angiotensin-stimulated colon sacs. The results are discussed in relation to the possibility that protein synthesis, at the stage of translation, is involved in the action of angiotensin on fluid transport by the colon.

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