scholarly journals Metabolic rate and rates of protein turnover in food-deprived cuttlefish, Sepia officinalis (Linnaeus 1758)

2016 ◽  
Vol 310 (11) ◽  
pp. R1160-R1168 ◽  
Author(s):  
Simon G. Lamarre ◽  
Tyson J. MacCormack ◽  
Antonio V. Sykes ◽  
Jennifer R. Hall ◽  
Ben Speers-Roesch ◽  
...  

To determine the metabolic response to food deprivation, cuttlefish ( Sepia officinalis) juveniles were either fed, fasted (3 to 5 days food deprivation), or starved (12 days food deprivation). Fasting resulted in a decrease in triglyceride levels in the digestive gland, and after 12 days, these lipid reserves were essentially depleted. Oxygen consumption was decreased to 53% and NH4 excretion to 36% of the fed group following 3–5 days of food deprivation. Oxygen consumption remained low in the starved group, but NH4 excretion returned to the level recorded for fed animals during starvation. The fractional rate of protein synthesis of fasting animals decreased to 25% in both mantle and gill compared with fed animals and remained low in the mantle with the onset of starvation. In gill, however, protein synthesis rate increased to a level that was 45% of the fed group during starvation. In mantle, starvation led to an increase in cathepsin A-, B-, H-, and L-like enzyme activity and a 2.3-fold increase in polyubiquitin mRNA that suggested an increase in ubiquitin-proteasome activity. In gill, there was a transient increase in the polyubiquitin transcript levels in the transition from fed through fasted to the starved state and cathepsin A-, B-, H-, and L-like activity was lower in starved compared with fed animals. The response in gill appears more complex, as they better maintain rates of protein synthesis and show no evidence of enhanced protein breakdown through recognized catabolic processes.

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 1196-1196
Author(s):  
Nathalie Atallah ◽  
Claire Gaudichon ◽  
Audrey Boulier ◽  
Alain Baniel ◽  
Dalila Azzout-Marniche ◽  
...  

Abstract Objectives Age and adiposity can impact the digestibility of dietary proteins and the metabolic response to their ingestion. The objective was to evaluate the effects of age and adiposity on casein digestibility and protein synthesis in tissues and organs. Methods Wistar rats of 1 month (n = 15) and 10 months (n = 15) at their arrival were fed ad libitum with a standard diet or High Fat diet to obtain rats of normal and high adiposity levels. Four groups were constituted (n = 7/8): 2 months/normal adiposity, 2 months/high adiposity, 11 months/normal adiposity and 11 months/high adiposity. At the end of the dietary intervention, they were fed the standard diet for 1 week before the test meal. The rats consumed a 4g meal containing 15N-labeled casein (Prodiet® 85B). Six hours after meal ingestion, the rats were euthanized. Intravenous injection of a massive dose of 13C-valine prior to euthanasia was used to determine protein synthesis rate in liver, kidneys, skin and muscle. Body composition was evaluated and digestive contents were collected to measure casein digestibility. Results No weight difference between rats of the same age was observed. However, a significant difference in adiposity was noted, with a surge in body fat of 3% in young rats and 7% in older rats. Digestibility increased with a higher adiposity level (P = 0.04). In young rats, it was 94.1 ± 1.1% in lean rats and 95.2 ± 1.7% in fat rats. In older rats, it was 94.5 ± 2.2% and 95.8 ± 0.7%, in lean and fat rats respectively. Significant effects of age (P < 0.01) and adiposity (P < 0.01) were observed in the muscle fractional synthesis rate (FSR), with age decreasing it and adiposity increasing it. In young rats, FSR was 10.1 ± 2.1%/day and 12.0 ± 3.0%/day in lean and fat rats, respectively, these values being 6.2 ± 1.5%/day and 10.6 ± 2.0%/day in older rats. In the skin, younger rats exhibited a higher FSR (P < 0.01) as it was 11.1 ± 2.6%/day and 12.6 ± 3.7%/day in lean and fat rats respectively, and 8.3 ± 2.3%/day and 8.2 ± 2.7%/day in older rats. No differences were found for the liver and kidneys. Conclusions Protein synthesis in muscle decreased with age while adiposity increased it. This is consistent with an improvement in ribosomal activity at an intermediate state of obesity. The surge in casein digestibility with higher adiposity, although moderate, could have contributed to the improvement in muscle anabolism response. Funding Sources Ingredia.


1981 ◽  
Vol 51 (1) ◽  
pp. 73-77 ◽  
Author(s):  
K. R. Tucker ◽  
M. J. Seider ◽  
F. W. Booth

Fractional rates of protein synthesis in rats were determined by the constant-infusion technique. Rates of protein synthesis in the gastrocnemius muscle were significantly reduced from control values throughout a 7-day period of hindlimb immobilization and 1) significantly increased to control values during the first 6 h following the 7-day period of hindlimb immobilization; 2) remained at control values for the next 2 days; and 3) then significantly increased to about twice control values on the 4th day following immobilization. Exercise of sufficient duration and/or intensity affected a further increase in the protein synthesis rate during recovery from atrophy. For example, running on a motor-driven treadmill 1 h daily for 3 days after ending limb immobilization resulted in a significant increase in the fractional rate of protein synthesis in the gastrocnemius muscle on the 2nd day following immobilization. Also, weight lifting for 200 s on the 2nd day of protein synthesis in the gastrocnemius muscle. Thus increased usage of atrophied muscle was followed by an increased rate of protein synthesis.


1990 ◽  
Vol 258 (1) ◽  
pp. H207-H211 ◽  
Author(s):  
R. B. Biggs ◽  
F. W. Booth

The purpose of these experiments was to determine whether mixed protein synthesis rates in hearts of Fischer 344 rats were decreased from maturity to senescence. When compared with 12-mo-old rat hearts, hearts from 23- to 25-mo-old rats had 13% lower concentrations of noncollagen protein, 9% less non-collagen protein per heart, 10% higher ratio of heart wet weight-to-body weight, and no difference in the basal rate of mixed protein synthesis, when expressed as fractional rate per day. Despite the 9% decrease in total noncollagen protein in 23- to 25-mo-old rat hearts, the derived value for milligrams protein synthesized per day was not different between age groups. When triiodothyronine was given for 3 days to mature and senescent rats, fractional rates of mixed protein synthesis were increased by similar percents (57–70%) in hearts from these two age groups. Basal and triiodothyronine-stimulated RNA concentrations in hearts of 12-mo-old and 23- to 25-mo-old rats were not different. These observations showed no decrease in either the basal or the maximal thyroid-stimulated rates of mixed protein synthesis in the hearts between mature and senescent rats. Thus an aging-programmed downregulation of mixed protein synthesis rates within cardiac muscle did not occur in the senescent Fischer 344 rat heart in this study.


1987 ◽  
Vol 247 (3) ◽  
pp. 525-530 ◽  
Author(s):  
C S Harmon ◽  
J H Park

The rate of epidermal protein synthesis in vivo was determined in the hairless mouse by a method in which a large dose of [3H]phenylalanine (150 mumol/100 g body wt.) is administered via the tail vein. The epidermal free phenylalanine specific radioactivity rapidly rose to a plateau value which by 10 min approached that of plasma, after which it declined. This dose of phenylalanine did not of itself alter protein synthesis rates, since incorporation of co-injected tracer doses of [3H]lysine and [14C]threonine was unaffected. The fractional rate of protein synthesis obtained for epidermis was 61.6%/day, whereas values for liver and gastrocnemius muscle in the same group of mice were 44%/day and 4.8%/day respectively. When expressed on the basis of RNA content, the value for epidermis (18.6 mg of protein/day per mg of RNA) was approx. 3-fold higher than those for liver and gastrocnemius muscle. Topical administration of 0.1% triamcinolone acetonide increased the epidermal fractional protein synthesis rate by 33% after 1 day and by 69% after 7 days, compared with vehicle-treated controls. These effects were entirely accounted for by the increase in protein synthesis rates per mg of RNA. RNA/protein ratios were unaffected by this treatment.


2015 ◽  
Vol 173 (1) ◽  
pp. R25-R34 ◽  
Author(s):  
Jorn Trommelen ◽  
Bart B L Groen ◽  
Henrike M Hamer ◽  
Lisette C P G M de Groot ◽  
Luc J C van Loon

BackgroundThough it is well appreciated that insulin plays an important role in the regulation of muscle protein metabolism, there is much discrepancy in the literature on the capacity of exogenous insulin administration to increase muscle protein synthesis ratesin vivoin humans.ObjectiveTo assess whether exogenous insulin administration increases muscle protein synthesis rates in young and older adults.DesignA systematic review of clinical trials was performed and the presence or absence of an increase in muscle protein synthesis rate was reported for each individual study arm. In a stepwise manner, multiple models were constructed that excluded study arms based on the following conditions: model 1, concurrent hyperaminoacidemia; model 2, insulin-induced hypoaminoacidemia; model 3, supraphysiological insulin concentrations; and model 4, older, more insulin resistant, subjects.ConclusionsFrom the presented data in the current systematic review, we conclude that: i) exogenous insulin and amino acid administration effectively increase muscle protein synthesis, but this effect is attributed to the hyperaminoacidemia; ii) exogenous insulin administered systemically induces hypoaminoacidemia which obviates any insulin-stimulatory effect on muscle protein synthesis; iii) exogenous insulin resulting in supraphysiological insulin levels exceeding 50 000 pmol/l may effectively augment muscle protein synthesis; iv) exogenous insulin may have a diminished effect on muscle protein synthesis in older adults due to age-related anabolic resistance; and v) exogenous insulin administered systemically does not increase muscle protein synthesis in healthy, young adults.


1988 ◽  
Vol 255 (2) ◽  
pp. E166-E172 ◽  
Author(s):  
M. M. Jepson ◽  
P. C. Bates ◽  
P. Broadbent ◽  
J. M. Pell ◽  
D. J. Millward

Muscle glutamine concentration ([GLN]) and protein synthesis rate (Ks) have been examined in vivo in well-fed, protein-deficient, starved, and endotoxemic rats. With protein deficiency (8 or 5% casein diet), [GLN] fell from 7.70 to 5.58 and 3.56 mmol/kg in the 8 and 5% diet groups, with Ks falling from 15.42 to 9.1 and 6.84%/day. Three-day starvation reduced [GLN] and Ks to 2.38 mmol/kg and 5.6%/day, respectively. In all these groups food intakes and insulin were generally well maintained (except in the starved group), whereas free 3,5,3'-triiodothyronine (T3) was depressed in the starved and 5% protein group. The E. coli lipopolysaccharide endotoxin (3 mg/kg) reduced [GLN] to 5.85 and 4.72 mmol/kg and Ks to 10.5 and 9.10%/day in two well-fed groups. Insulin levels were increased, and free T3 levels fell. Combined protein deficiency and endotoxemia further reduced [GLN] and Ks to 1.88 mmol/kg and 4.01%/day, respectively, in the 5% protein rats. Changes in both ribosomal activity (KRNA) and concentration (RNA/protein) contributed to the fall in Ks in malnutrition and endotoxemia, although reductions in the RNA concentration were most marked with protein deficiency and reductions in the KRNA dominated the response to the endotoxin. The changes in [GLN] and Ks were highly correlated as were [GLN] and both KRNA and the RNA concentration, and these relationships were unique to glutamine. These relationships could reflect sensitivity of glutamine transport and protein synthesis to the same regulatory influences, and the particular roles of insulin and T3 are discussed, as well as any direct influence of glutamine on protein synthesis.


2009 ◽  
Vol 55 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Kazuyo TUJIOKA ◽  
Miho OHSUMI ◽  
Kenji HORIE ◽  
Mujo KIM ◽  
Kazutoshi HAYASE ◽  
...  

2012 ◽  
Vol 58 (4) ◽  
pp. 297-302 ◽  
Author(s):  
Kazuyo TUJIOKA ◽  
Takashi YAMADA ◽  
Mami AOKI ◽  
Koji MORISHITA ◽  
Kazutoshi HAYASE ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sarah L. Gillen ◽  
Chiara Giacomelli ◽  
Kelly Hodge ◽  
Sara Zanivan ◽  
Martin Bushell ◽  
...  

Abstract Background Regulation of protein output at the level of translation allows for a rapid adaptation to dynamic changes to the cell’s requirements. This precise control of gene expression is achieved by complex and interlinked biochemical processes that modulate both the protein synthesis rate and stability of each individual mRNA. A major factor coordinating this regulation is the Ccr4-Not complex. Despite playing a role in most stages of the mRNA life cycle, no attempt has been made to take a global integrated view of how the Ccr4-Not complex affects gene expression. Results This study has taken a comprehensive approach to investigate post-transcriptional regulation mediated by the Ccr4-Not complex assessing steady-state mRNA levels, ribosome position, mRNA stability, and protein production transcriptome-wide. Depletion of the scaffold protein CNOT1 results in a global upregulation of mRNA stability and the preferential stabilization of mRNAs enriched for G/C-ending codons. We also uncover that mRNAs targeted to the ER for their translation have reduced translational efficiency when CNOT1 is depleted, specifically downstream of the signal sequence cleavage site. In contrast, translationally upregulated mRNAs are normally localized in p-bodies, contain disorder-promoting amino acids, and encode nuclear localized proteins. Finally, we identify ribosome pause sites that are resolved or induced by the depletion of CNOT1. Conclusions We define the key mRNA features that determine how the human Ccr4-Not complex differentially regulates mRNA fate and protein synthesis through a mechanism linked to codon composition, amino acid usage, and mRNA localization.


1995 ◽  
Vol 89 (4) ◽  
pp. 383-388 ◽  
Author(s):  
Peter W. Emery ◽  
Peter Sanderson

1. The healing of an abdominal muscle wound after surgery is associated with a considerable increase in the rate of protein synthesis. We have investigated whether this increase in protein synthesis is affected by chronic undernutrition, and whether this causes a delay in wound healing. 2. A group of rats was fed 58% of the voluntary food intake of a matched control group. After 7 days half the rats in each group underwent abdominal surgery. Forty-eight hours later all the rats were killed and muscle protein synthesis rate was measured by the flooding dose technique. 3. In a second experiment using the same dietary regimen rats were placed in metabolic cages after surgery and killed 7 days later. In addition to measurements of muscle protein synthesis, wound breaking strength was measured with a tensiometer and collagen content was also measured at the wound site. 4. Dietary restriction caused a loss of body weight, a decrease in nitrogen balance and a deficit in muscle protein mass. It also caused a decrease in protein synthesis rate in gastrocnemius muscle and in parts of the abdominal muscle distant from the site of the wound. However, it had no effect on the rate of muscle protein synthesis at the site of the wound either 2 or 7 days after surgery. The tensile strength and the collagen content of the wound were also unaffected by food restriction. 5. It is concluded that the wound healing process is uniquely protected from the effects of moderate undernutrition such as might be experienced by a chronically ill patient.


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