Acute changes in biliary excretion of reverse triiodothyronine in rats after insulin-induced hypoglycemia: effect of glucose, verapamil, cycloheximide and actinomycin D

1995 ◽  
Vol 132 (5) ◽  
pp. 618-621 ◽  
Author(s):  
Pavel Langer ◽  
Klaudia Gschwendtová
Keyword(s):  
Protein Synthesis ◽  
Metabolic Activity ◽  
Biliary Excretion ◽  
Actinomycin D ◽  
Slovak Academy ◽  
Similar Increase ◽  
Reverse Triiodothyronine ◽  
Acute Changes ◽  
Academy Of Sciences ◽  
Effect Of Glucose

Langer P, Gschwendtová K. Acute changes in biliary excretion of reverse triiodothyronine in rats after insulin-induced hypoglycemia: effect of glucose, verapamil, cycloheximide and actinomycin D. Eur J Endocrinol 1995;132:618–21. ISSN 0804–4643 Biliary excretion of reverse triiodothyronine (rT3) was estimated in rats during hypoglycemia induced by a 10-min infusion of 1 U of insulin (INS) and for the following 5 h. During that period an increase in biliary rT3 was found. This was seen also during the infusion of exogenous glucagon (10 μg in 1.2 ml of saline per 1 h for 5 h) given independently of INS. The infusion of glucose (1 g/kg per 50 min or 2 g/kg per 110 min) following INS infusion delayed the increase in rT3. The increase in rT3 was prevented by actinomycin D (1 mg/kg) when injected before (90 min), but not after (30 min) INS, and also by cycloheximide (2.5 mg/kg) injected immediately before INS. The same dose of cycloheximide also prevented a similar increase of rT3 during the infusion of exogenous glucagon. Verapamil (5 mg/ kg divided into five doses per 4 h) blunted the increase of rT3. These data indicate that following INS injection counter-regulatory hormones may be responsible for the increased production of rT3; this altered metabolic activity apparently is dependent on protein synthesis. Pavel Langer, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlárska 3, 833 06 Bratislava, Slovakia

scholarly journals The separate roles of glucose and insulin in the induction of glucokinase in hepatocytes isolated from neonatal rats

1981 ◽  
Vol 196 (2) ◽  
pp. 383-390 ◽  
Author(s):  
M J Wakelam ◽  
D G Walker
Keyword(s):  
Protein Synthesis ◽  
Cyclic Amp ◽  
Actinomycin D ◽  
Neonatal Rats ◽  
Dibutyryl Cyclic Amp ◽  
Subsequent Effect ◽  
Old Rats ◽  
Effect Of Glucose

1. The specificity of the effect of glucose on the induction of glucokinase activity that occurs when hepatocytes freshly isolated from 13-day-old rats are incubated in Medium 199 together with insulin [Wakelam & Walker (1980) FEBS Lett. 111, 115-119] was examined. A pattern that is different from other known effects of glucose is found, and metabolism of this compound is not necessarily to account for this particular effect. 2. The effects of a raised glucose concentration and of insulin on the induction can be separated. The hexose initiates the process in the absence of insulin in a manner that is sensitive to actinomycin D but not to cycloheximide. The subsequent effect of insulin is dependent on the prior effect of glucose or other positive analogue, does not require the presence of glucose and is inhibited by cycloheximide but not by actinomycin D. 3. Induction of glucokinase in vitro in hepatocytes from neonatal animals is inhibited by adrenaline, glucagon and dibutyryl cyclic AMP, but not by vasopressin or angiotensin II. The inhibition by cyclic AMP is on the stage requiring insulin and is comparatively specific, because total protein synthesis is not apparently diminished. 4. The implications of these results are discussed with reference to possible mechanisms of induction and to the situation in vivo.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Lipopolysaccharide-induced sensitization of adenylyl cyclase activity in murine macrophages

2006 ◽  
Vol 290 (1) ◽  
pp. C143-C151 ◽  
Author(s):  
Y. Osawa ◽  
H. T. Lee ◽  
C. A. Hirshman ◽  
D. Xu ◽  
C. W. Emala
Keyword(s):  
Protein Synthesis ◽  
Adenylyl Cyclase ◽  
Actinomycin D ◽  
Inhibitory Effect ◽  
Cytokine Release ◽  
Adenylyl Cyclase Activity ◽  
Phosphorylation State ◽  
Murine Macrophages ◽  
Dependent Pathway ◽  
New Protein

LPS is known to modulate macrophage responses during sepsis, including cytokine release, phagocytosis, and proliferation. Although agents that elevate cAMP reverse LPS-induced macrophage functions, whether LPS itself modulates cAMP and whether LPS-induced decreases in proliferation are modulated via a cAMP-dependent pathway are not known. Murine macrophages (RAW264.7 cells) were treated with LPS in the presence or absence of inhibitors of prostaglandin signaling, protein kinases, CaM, Giproteins, and NF-κB translocation or transcription/translation. LPS effects on CaMKII phosphorylation and the expression of relevant adenylyl cyclase (AC) isoforms were measured. LPS caused a significant dose (5–10,000 ng/ml)- and time (1–8 h)-dependent increase in forskolin-stimulated AC activity that was abrogated by pretreatment with SN50 (an NF-κB inhibitor), actinomycin D, or cycloheximide, indicating that the effect is mediated via NF-κB-dependent transcription and new protein synthesis. Furthermore, LPS decreased the phosphorylation state of CaMKII, and pretreatment with a CaM antagonist attenuated the LPS-induced sensitization of AC. LPS, cAMP, or PKA activation each independently decreased macrophage proliferation. However, inhibition of NF-κB had no effect on LPS-induced decreased proliferation, indicating that LPS-induced decreased macrophage proliferation can proceed via PKA-independent signaling pathways. Taken together, these findings indicate that LPS induces sensitization of AC activity by augmenting the stimulatory effect of CaM and attenuating the inhibitory effect of CaMKII on isoforms of AC that are CaMK sensitive.

Effects of Actinomycin D on RNA Transcription, Protein Synthesis, and Nuclear Structure

1970 ◽  
pp. 491-515 ◽  
Author(s):  
Harold Koenig ◽  
Chung Y. Lu ◽  
Stanley Jacobson ◽  
Panna Sanghavi ◽  
Rajinder Nayyar
Keyword(s):  
Protein Synthesis ◽  
Nuclear Structure ◽  
Actinomycin D ◽  
Rna Transcription

Effects of glucose, pyruvate, lactate, and amino acids on muscle protein synthesis

1982 ◽  
Vol 242 (3) ◽  
pp. E184-E192 ◽  
Author(s):  
M. P. Hedden ◽  
M. G. Buse
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Creatine Phosphate ◽  
Serum Amino Acids ◽  
14Co2 Production ◽  
Beta Hydroxybutyrate ◽  
Free Media ◽  
Effect Of Glucose

Protein synthesis was measured in rat diaphragms incubated with serum amino acids + 0.35 mM L-[2,6-3H]tyrosine and different energy-yielding substrates. Muscles incubated with 5.5 mM glucose (with or without actinomycin D) synthesized more protein than those incubated with 11 mM pyruvate or 11 mM lactate. Tissue ATP decreased during incubation with lactate, but pyruvate maintained ATP, ADP, and creatine phosphate as well as glucose. Glucose 6-phosphate decreased in muscles incubated in glucose-free media. 14CO2 production from substrates was [1-14C]pyruvate greater than [1-14C]lactate greater than [3,4-14C]glucose. Intracellular lactate/pyruvate was measured to assess cytoplasmic free NADH/NAD+; the effect of different media on these ratios was lactate greater than glucose = lactate + pyruvate greater than pyruvate + glucose greater than pyruvate. Lactate + pyruvate (8.8 + 2.2 mM) supported protein synthesis better than pyruvate and as well as glucose. Adding glucose to pyruvate accelerated protein synthesis and increased NADH/NAD+. Iodoacetate (0.1 mM) inhibited glycolytic NAD reduction and abolished the stimulatory effect of glucose on protein synthesis in the presence of pyruvate. Supplementation of pyruvate media with 1 mM leucine or isoleucine stimulated protein synthesis, but beta-hydroxybutyrate, malate, alpha-ketoisocaproate, and all other amino acids were ineffective. The cytoplasmic redox potential may act as a translational modulator of protein synthesis in skeletal muscle.

scholarly journals Poly(A) tail shortening is the translation-dependent step in c-myc mRNA degradation.

1990 ◽  
Vol 10 (12) ◽  
pp. 6132-6140 ◽  
Author(s):  
I A Laird-Offringa ◽  
C L de Wit ◽  
P Elfferich ◽  
A J van der Eb
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
Degradation Pathway ◽  
Mrna Degradation ◽  
The Body ◽  
Second Step ◽  
Protein Synthesis Inhibitors ◽  
Rapid Degradation ◽  
Translation Block ◽  
Insight Into

The highly unstable c-myc mRNA has been shown to be stabilized in cells treated with protein synthesis inhibitors. We have studied this phenomenon in an effort to gain more insight into the degradation pathway of this mRNA. Our results indicate that the stabilization of c-myc mRNA in the absence of translation can be fully explained by the inhibition of translation-dependent poly(A) tail shortening. This view is based on the following observations. First, the normally rapid shortening of the c-myc poly(A) tail was slowed down by a translation block. Second, c-myc messengers which carry a short poly(A) tail, as a result of prolonged actinomycin D or 3'-deoxyadenosine treatment, were not stabilized by the inhibition of translation. We propose that c-myc mRNA degradation proceeds in at least two steps. The first step is the shortening of long poly(A) tails. This step requires ongoing translation and thus is responsible for the delay in mRNA degradation observed in the presence of protein synthesis inhibitors. The second step involves rapid degradation of the body of the mRNA, possibly preceded by the removal of the short remainder of the poly(A) tail. This last step is independent of translation.

Cytoplasmic regulation of translation during Ilyanassa embryogenesis

Development ◽  
1989 ◽  
Vol 106 (2) ◽  
pp. 263-269
Author(s):  
Collier JR
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
Specific Gene ◽  
Early Cleavage ◽  
Polar Lobe ◽  
Nuclear Activity ◽  
Two Dimensional Electrophoresis ◽  
Regulation Of Translation ◽  
Maternal Mrnas ◽  
Dimensional Electrophoresis

Two-dimensional electrophoresis of labeled proteins and hybridization of mRNAs with specific gene probes was demonstrate changes in protein synthesis, and the of actin maternal mRNAs during the early development isolated polar lobe was used as a nucleus-free egg the regulation of translation. It was shown that actin present in the unfertilized egg and are therefore are inactive during early cleavage, and are translated lobeless, actinomycin D-treated blastulae and in that have been aged for 24h. Thus, the activation of controlled by cytoplasmic factors that function cleavage and nuclear activity. I suggest that the cytoplasmic clock determines when maternal mRNAs are that this clock is made and set running during protein synthesis that occurred during early cleavage also involve the diminution of some early cleavage suggested that this diminution is controlled by localized in the blastomeres of the lobeless egg but polar lobe.

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