An Experimental Model for the Investigation of Purine Biosynthesis de novo in Rat Skeletal Muscle

1977 ◽  
Vol 5 (6) ◽  
pp. 1753-1755 ◽  
Author(s):  
T. GERARD SHEEHAN ◽  
BRENDAN M. BUCKLEY ◽  
ERIC R. TULLY
Keyword(s):  
Skeletal Muscle ◽  
Experimental Model ◽  
De Novo ◽  
Purine Biosynthesis ◽  
Rat Skeletal Muscle

scholarly journals Purine biosynthesis de novo in rat skeletal muscle

1983 ◽  
Vol 216 (3) ◽  
pp. 605-610 ◽  
Author(s):  
T G Sheehan ◽  
E R Tully
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
De Novo ◽  
Adenine Nucleotides ◽  
Extensor Digitorum ◽  
Purine Biosynthesis ◽  
Rat Skeletal Muscle ◽  
Purine Synthesis ◽  
Longus Muscle ◽  
Isolated Rat

Purine biosynthesis by the ‘de novo’ pathway was demonstrated in isolated rat extensor digitorum longus muscle with [1-14C]glycine, [3-14C]serine and sodium [14C]formate as nucleotide precursors. Evidence is presented which suggests that the source of glycine and serine for purine biosynthesis is extracellular rather than intracellular. The relative incorporation rates of the three precursors were formate greater than glycine greater than serine. Over 85% of the label from formate and glycine was recovered in the adenine nucleotides, principally ATP. Azaserine markedly inhibited purine biosynthesis from both formate and glycine. Cycloserine inhibited synthesis from serine, but not from formate. Adenine, hypoxanthine and adenosine markedly inhibited purine synthesis from sodium [14C]formate.

scholarly journals USP19 is a ubiquitin-specific protease regulated in rat skeletal muscle during catabolic states

2005 ◽  
Vol 288 (4) ◽  
pp. E693-E700 ◽  
Author(s):  
Lydie Combaret ◽  
Olasunkanmi A. J. Adegoke ◽  
Nathalie Bedard ◽  
Vickie Baracos ◽  
Didier Attaix ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
De Novo ◽  
Deubiquitinating Enzyme ◽  
Mrna Levels ◽  
Deubiquitinating Enzymes ◽  
Rat Skeletal Muscle ◽  
Ubiquitin System ◽  
Specific Protease ◽  
Ubiquitin Specific Protease

Ubiquitin-dependent proteolysis is activated in skeletal muscle atrophying in response to various catabolic stimuli. Previous studies have demonstrated activation of ubiquitin conjugation. Because ubiquitination can also be regulated by deubiquitinating enzymes, we used degenerate oligonucleotides derived from conserved sequences in the ubiquitin-specific protease (UBP) family of deubiquitinating enzymes in RT-PCR with skeletal muscle RNA to amplify putative deubiquitinating enzymes. We identified USP19, a 150-kDa deubiquitinating enzyme that is widely expressed in various tissues including skeletal muscle. Expression of USP19 mRNA increased by ∼30–200% in rat skeletal muscle atrophying in response to fasting, streptozotocin-induced diabetes, dexamethasone treatment, and cancer. Increased mRNA levels during fasting returned to normal with refeeding, but 1 day later than the normalization of rates of proteolysis and coincided instead with recovery of muscle mass. Indeed, in all catabolic treatments, USP19 mRNA was inversely correlated with muscle mass and provided an index of muscle mass that may be useful in many pathological conditions, using small human muscle biopsies. The increased expression of this deubiquitinating enzyme under conditions of increased proteolysis suggests that it may play a role in regeneration of free ubiquitin either coincident with or after proteasome-mediated degradation of substrates. USP19 may also be involved in posttranslational processing of polyubiquitin produced de novo in response to induction of the polyubiquitin genes seen under these conditions. Deubiquitinating enzymes thus appear involved in muscle wasting and implicate a widening web of regulation of genes in the ubiquitin system in this process.

scholarly journals Hyperinsulinemia does not cause de novo capillary recruitment in rat skeletal muscle

2019 ◽  
Vol 27 (2) ◽  
Author(s):  
Thorbjorn Akerstrom ◽  
Daniel Goldman ◽  
Franciska Nilsson ◽  
Stephanie L. Milkovich ◽  
Graham M. Fraser ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
De Novo ◽  
Rat Skeletal Muscle ◽  
Capillary Recruitment
Sign in / Sign up

Export Citation Format

Share Document