Effect of actinomycin D on RNA and protein synthesis in regions of developing frog embryos

1970 ◽  
Vol 26 (7) ◽  
pp. 778-779 ◽  
Author(s):  
R. A. Flickinger
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
Rna And Protein Synthesis

Regulation of K+ Influx in Barley Roots: Evidence for Direct Control by Internal K+

1977 ◽  
Vol 4 (2) ◽  
pp. 313 ◽  
Author(s):  
ADM Glass
Keyword(s):  
Protein Synthesis ◽  
Cell Division ◽  
Actinomycin D ◽  
Direct Control ◽  
Pretreatment Period ◽  
Rna And Protein Synthesis ◽  
Lag Period ◽  
Limited Protein ◽  
K Concentration ◽  
Gamma Irradiated

Values for plasmalemma influx of K+ into excised barley roots, from solutions containing 0.05 mM KCl plus 0.5 mM CaSO4, were reduced by 50-60% following a 6-h pretreatment period in 50 mM KCl plus 0.05 mM CaSO4 solution. This reduction of influx, associated with increased internal K+ concentration, was independent of DNA, RNA and protein synthesis during the pretreatment period as indicated by its insensitivity to the presence of 5-fluorodeoxyuridine, actinomycin D, cycloheximide, p-fluorophenylalanine or anisomycin in the pretreatment solutions. Roots of plantlets grown from gamma-irradiated barley seeds, which were incapable of under-going cell division and capable of only limited protein synthesis, were nevertheless able to reduce K+ influx values in response to increased internal K+ concentration. The measurement of K+ influx from 0.05 mM KCl solutions following pretreatment periods as short as 15 min in 50 mM KCl gave no evidence of any lag period in the development of reduced influx associated with increased internal K+ status. The above experiments are discussed in terms of a model for the regulation of K+ influx which ascribes a direct 'allosteric' role to internal K+ in controlling influx.

scholarly journals Analysis of the survival of mature human eosinophils: interleukin-5 prevents apoptosis in mature human eosinophils

Blood ◽  
1991 ◽  
Vol 78 (10) ◽  
pp. 2542-2547 ◽  
Author(s):  
Y Yamaguchi ◽  
T Suda ◽  
S Ohta ◽  
K Tominaga ◽  
Y Miura ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dna Fragmentation ◽  
Culture System ◽  
Actinomycin D ◽  
Agar Gel ◽  
Interleukin 5 ◽  
Liquid Culture System ◽  
Rna And Protein Synthesis ◽  
Agar Gel Electrophoresis

Abstract We and other groups have previously shown that interleukin-5 (IL-5) maintained the viability of mature eosinophils in an in vitro liquid culture system. Mature eosinophils did not proliferate but their survival was maintained in the presence of IL-5. Using this culture system, we investigated the mechanism of IL-5-mediated survival. In the absence of human IL-5 (hIL-5) mature eosinophils succumbed after 4 days, while in the presence of hIL-5 they survived up to 10 days. When DNA extracts of cultured eosinophils were analyzed on an agar gel electrophoresis, marked DNA fragmentation was observed in the absence of hIL-5, while no significant DNA fragmentation was observed in the culture with hIL-5 for 48 hours. The DNA fragmentation appeared as early as 6 to 12 hours after hIL-5 deprivation. Concomitantly, IL-5 stimulated total RNA and protein synthesis, but did not induce DNA synthesis in mature eosinophils. Because cycloheximide or actinomycin D impeded the protection of apoptosis by hIL-5, some new RNA and protein synthesis appeared to be required in this phenomena. These findings indicate that IL-5 maintains survival of mature eosinophils with induction of new RNA and protein synthesis, thus leading to the inhibition of apoptosis.

PRIMING EFFECT OF LUTEINIZING HORMONE RELEASING FACTOR: IN-VITRO AND IN-VIVO EVIDENCE CONSISTENT WITH ITS DEPENDENCE UPON PROTEIN AND RNA SYNTHESIS

1976 ◽  
Vol 69 (3) ◽  
pp. 373-379 ◽  
Author(s):  
A. J. M. C. PICKERING ◽  
G. FINK
Keyword(s):  
Protein Synthesis ◽  
Priming Effect ◽  
Actinomycin D ◽  
Protein S ◽  
In Vivo Studies ◽  
Protein And Rna Synthesis ◽  
Rna And Protein Synthesis ◽  
Secretory Apparatus

SUMMARY The aim of this study was to determine whether the priming effect of LH-RF depends upon RNA and protein synthesis. In in-vivo studies saline, actinomycin D, or cycloheximide was administered i.p. 3·5–4 h before the first i.v. injection of synthetic LH-RF into pro-oestrous rats anaesthetized with sodium pentobarbitone at 13.30 h. The LH-response to the second injection of LH-RF (given 60 min after the first) was markedly reduced by the inhibitors, but the response to the first injection was not significantly affected. Studies with cycloheximide given i.v. showed that the inhibition of protein synthesis up to the second injection of LH-RF reduced the magnitude of the priming effect, the reduction being greatest when the inhibitor was administered up to 30 min after the first LH-RF injection. Pituitary incubation studies showed that the priming effect could also be elicited in vitro and that it could be significantly reduced by actinomycin D, cycloheximide and puromycin. As in vivo, the inhibitors had relatively little effect on the LH-response to the first exposure to LH-RF. The protein synthesized after an injection of LH-RF may be new LH, and/or a protein(s) concerned with 'activation' of the receptor or release components of the LH-secretory apparatus.

Rapid effects of insulin on uridine metabolism in mammary gland explants

1975 ◽  
Vol 228 (5) ◽  
pp. 1531-1534 ◽  
Author(s):  
JA Rillema
Keyword(s):  
Protein Synthesis ◽  
Mammary Gland ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Complete Suppression ◽  
Metabolic Fate ◽  
Inhibit Protein Synthesis ◽  
Uridine Uptake ◽  
Rna And Protein Synthesis ◽  
Stimulation Of

A study was made of the early actions of insulin on uridine metabolism in mammary glang explants. A stimulation of both labeled uridine uptake and its incorporation into RNA was demonstrated as early as 15 min after addition of insulin to medium bathing the tissue; these effects persisted for several hours. The metabolic fate of [3-H] uridine to UMP, UDP, and UTP was observed, whereas insulin had no effect on the quantity of 3-H present as uridine or uracil in these tissues. Further studies were performed in which insulin was also shown to have a rapid stimulatory effect on the incorporation of [32-P] phosphate into RNA; however, the uptake of the labeled phosphate was not affected by insulin. Experiments were also carried out to determine whether the effects of insulin on labeled uridine uptake require ongoing RNA and protein synthesis and whether uridine incorporation depends on concomitant protein synthesis. Incubation of explants with antibiotics which inhibit protein synthesis resulted in the complete suppression of the effects of insulin on labeled uridine uptake and its incorporation into RNA. In contrast, the effect of insulin on labeled uridine uptake does not appear to require ongoing RNA synthesis, since this effect persisted when RNA synthesis was significantly reduced by the presence of actinomycin D.

scholarly journals Analysis of the survival of mature human eosinophils: interleukin-5 prevents apoptosis in mature human eosinophils

Blood ◽  
1991 ◽  
Vol 78 (10) ◽  
pp. 2542-2547 ◽  
Author(s):  
Y Yamaguchi ◽  
T Suda ◽  
S Ohta ◽  
K Tominaga ◽  
Y Miura ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dna Fragmentation ◽  
Culture System ◽  
Actinomycin D ◽  
Agar Gel ◽  
Interleukin 5 ◽  
Liquid Culture System ◽  
Rna And Protein Synthesis ◽  
Agar Gel Electrophoresis

We and other groups have previously shown that interleukin-5 (IL-5) maintained the viability of mature eosinophils in an in vitro liquid culture system. Mature eosinophils did not proliferate but their survival was maintained in the presence of IL-5. Using this culture system, we investigated the mechanism of IL-5-mediated survival. In the absence of human IL-5 (hIL-5) mature eosinophils succumbed after 4 days, while in the presence of hIL-5 they survived up to 10 days. When DNA extracts of cultured eosinophils were analyzed on an agar gel electrophoresis, marked DNA fragmentation was observed in the absence of hIL-5, while no significant DNA fragmentation was observed in the culture with hIL-5 for 48 hours. The DNA fragmentation appeared as early as 6 to 12 hours after hIL-5 deprivation. Concomitantly, IL-5 stimulated total RNA and protein synthesis, but did not induce DNA synthesis in mature eosinophils. Because cycloheximide or actinomycin D impeded the protection of apoptosis by hIL-5, some new RNA and protein synthesis appeared to be required in this phenomena. These findings indicate that IL-5 maintains survival of mature eosinophils with induction of new RNA and protein synthesis, thus leading to the inhibition of apoptosis.

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