THE HORMONAL REGULATION OF ACTIVE ELECTROGENIC Na+-K+-TRANSPORT IN SKELETAL MUSCLE

1981 ◽  
pp. 209-220 ◽  
Author(s):  
T. Clausen
Keyword(s):  
Skeletal Muscle ◽  
Hormonal Regulation ◽  
K Transport

Hormonal regulation of core clock gene expression in skeletal muscle following acute aerobic exercise

2019 ◽  
Vol 508 (3) ◽  
pp. 871-876 ◽  
Author(s):  
Patrick G. Saracino ◽  
Michael L. Rossetti ◽  
Jennifer L. Steiner ◽  
Bradley S. Gordon
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Aerobic Exercise ◽  
Hormonal Regulation ◽  
Clock Gene ◽  
Clock Gene Expression ◽  
Core Clock Gene

Ion transport in circulatory and/or septic shock

1987 ◽  
Vol 252 (5) ◽  
pp. R809-R821 ◽  
Author(s):  
M. M. Sayeed
Keyword(s):  
Skeletal Muscle ◽  
Ion Transport ◽  
Hepatic Glucose Production ◽  
Endotoxic Shock ◽  
Extracellular Fluid ◽  
Glucose Production ◽  
Metabolic Energy ◽  
Primate Species ◽  
K Transport ◽  
Membrane Ion Transport

This review surveys investigations of membrane ion transport in animals in hemorrhagic, endotoxic, or bacteremic shock. The focus of the review is on ion transport studies in the skeletal muscle and liver. Skeletal muscle Na+-K+ transport alterations have been shown during the induction of shock via hemorrhage, endotoxin, or live Gram-negative bacteria in the rodent, canine, and primate species. These alterations include impairment of active cellular K+ accumulation, increased permeability to Na+ and Cl-, and membrane depolarization. The ion transport alterations in the skeletal muscle are compatible with movement of extracellular fluid into the intracellular compartment. Such fluid movements can potentially lead to decreases in circulating plasma volume and thus to circulatory deficits in shock. Studies in the liver of rats subjected to hemorrhagic or endotoxic shock indicated the failure of electrogenic Na+ pump. Although the hepatic cellular membrane permeability to Na+ relative to permeability to K+ appeared unaltered in hemorrhagic shock, endotoxic shock caused an increase in permeability to Na+. Hepatic cellular Ca+ regulation also appeared to be adversely affected during endotoxic shock. Alterations in hepatic Na+-K+ transport and Ca+ regulation could contribute to impairment in hepatic glucose production during shock. Although mechanisms of altered membrane ion transport during shock states remain unknown, such changes could occur prior to any substantial loss of cellular metabolic energy.

Effect of insulin on rat heart and skeletal muscle phenylalanyl-tRNA labeling and protein synthesis in vivo

1994 ◽  
Vol 267 (2) ◽  
pp. E337-E342 ◽  
Author(s):  
L. H. Young ◽  
W. Stirewalt ◽  
P. H. McNulty ◽  
J. H. Revkin ◽  
E. J. Barrett
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Hormonal Regulation ◽  
Specific Activity ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
In Vivo Measurement ◽  
Arterial Plasma ◽  
Kinetics Of

In vivo measurement of muscle protein synthesis and its hormonal regulation is limited by the difficulty of measuring aminoacyl-tRNA specific activity (SA). We assessed the kinetics of heart and skeletal muscle phenylalanyl-tRNA labeling during continuous infusion of L-[ring-2,6-3H]phenylalanine (Phe) to fasted anesthetized rats. We measured Phe SA in arterial and femoral venous plasma, the tissue acid-soluble pool and muscle protein hydrolysates after 5 min (n = 7), 30 min (n = 6), and 90 min (n = 7). We also assessed insulin's effect on labeling of the tRNA pool and muscle protein synthesis during a hyperinsulinemic clamp (2 mU.kg-1.min-1; n = 7). Labeling of tRNA in heart reached 59 +/- 5, 67 +/- 3, and 83 +/- 3% of arterial SA at 5, 30, and 90 min of saline infusion, respectively, but only 10 +/- 5, 34 +/- 2, and 48 +/- 2% in skeletal muscle at those times (P < 0.01 vs. heart). The tRNA SA was intermediate between SA in the acid-soluble pool and arterial plasma. Femoral venous SA was 32 +/- 2% lower (P < 0.001) than arterial SA. Skeletal muscle tRNA SA was also 29 +/- 3% lower (P < 0.001) than femoral venous SA. Insulin did not alter tRNA labeling and neither heart (9.8 +/- 1.1%/day for saline vs. 8.4 +/- 1.0%/day for insulin) nor skeletal muscle (6.7 +/- 1.5%/day vs. 4.2 +/- 0.4%/day) protein synthesis. Thus labeling of phenylalanyl-tRNA occurs more rapidly in heart than in skeletal muscle and is unaffected by insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Expression of the liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase mRNA in FAO-1 cells

1993 ◽  
Vol 293 (1) ◽  
pp. 173-179 ◽  
Author(s):  
C Espinet ◽  
A M Vargas ◽  
M R el-Maghrabi ◽  
A J Lange ◽  
S J Pilkis
Keyword(s):  
Skeletal Muscle ◽  
Cell Line ◽  
Rat Liver ◽  
Hormonal Regulation ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Bifunctional Enzyme ◽  
Dependent Manner ◽  
Rat Hepatoma Cell Line ◽  
Rat Hepatoma

The hormonal regulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene expression was studied in the rat hepatoma cell line FAO-1. Both 6-phosphofructo-2-kinase and fructose-2,6-bisphosphatase activities were detected in FAO-1 cells, at 68% of the levels found in rat liver. Northern blot analysis showed that FAO-1 cells, like rat liver, contained a predominant species of bifunctional enzyme mRNA, which is 2.2 kb in size. A sensitive RNAase protection assay revealed the presence in FAO-1 cells of an additional mRNA species, which is generated when transcription is initiated from the skeletal muscle promoter of the rat liver/skeletal muscle gene. The liver/skeletal muscle mRNA ratio in FAO-1 cells was 10:1, which is similar to that observed in rat liver. In contrast, in another rat hepatoma cell line, FTO-2B, only the skeletal muscle mRNA was detected. Insulin and dexamethasone induced the liver bifunctional enzyme mRNA in FAO-1 cells by 2-4-fold and 10-20-fold respectively in a concentration- and time-dependent manner, and their effects were antagonized by cyclic AMP. Transcription of the gene in FAO-1 cells, measured by nuclear run-on assays, was also enhanced by dexamethasone and insulin. It is concluded that the FAO-1 cell line is similar to liver with respect to both the preferential use of the liver promoter of the gene and its regulation by hormones, and is therefore an excellent model for the study of the hepatic expression of this gene.

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