scholarly journals Myofibrillar protein degradation in the chicken 3-Methylhistidine release in vivo and in vitro in normal and genetically muscular-dystrophic chickens

1981 ◽  
Vol 196 (2) ◽  
pp. 591-601 ◽  
Author(s):  
F. Bradley Hillgartner ◽  
Anne S. Williams ◽  
James A. Flanders ◽  
Dexter Morin ◽  
Robert J. Hansen
Keyword(s):  
Protein Degradation ◽  
Lactate Production ◽  
Pectoral Muscle ◽  
Myofibrillar Protein ◽  
Normal Muscle ◽  
Dystrophic Muscle ◽  
Degradation Rates ◽  
Release In Vitro

Myofibrillar protein degradation was measured in 4-week-old normal (line 412) and genetically muscular-dystrophic (line 413) New Hampshire chickens by monitoring the rates of 3-methylhistidine excretion in vivo and in vitro. A method of perfusing breast and wing muscles was developed and the rate of 3-methylhistidine release in vitro was measured between 30 and 90min of perfusion. During this perfusion period, 3-methylhistidine release from the muscle preparation was linear, indicating that changes in 3-methylhistidine concentration of the perfusate were the result of myofibrillar protein degradation. Furthermore, the viability of the perfused muscle was maintained during this interval. After 60min of perfusion, ATP, ADP and creatine phosphate concentrations in pectoral muscle were similar to muscle freeze-clamped in vivo. Rates of glucose uptake and lactate production were constant during the perfusion. In dystrophic-muscle preparations, the rate of 3-methylhistidine release in vitro (nmol/h per g of dried muscle) was elevated 2-fold when compared with that in normal muscle. From these data the fractional degradation rates of myofibrillar protein in normal and dystrophic pectoral muscle were calculated to be 12 and 24% respectively. Daily 3-methylhistidine excretion (nmol/day per g body wt.) in vivo was elevated 1.35-fold in dystrophic chickens. Additional studies revealed that the anti-dystrophic drugs diphenylhydantoin and methylsergide, which improve righting ability of dystrophic chickens, did not alter 3-methylhistidine release in vitro. This result implies that changes in myofibrillar protein turnover are not the primary lesion in avian muscular dystrophy. From tissue amino acid analysis, the myofibrillar 3-methylhistidine content per g dry weight of muscle was similar in normal and dystrophic pectoral muscle. More than 96% of the 3-methylhistidine present in pectoral muscle was associated with the myofibrillar fraction. Dystrophic myofibrillar protein contained significantly less 3-methylhistidine (nmol/g of myofibrillar protein) than protein from normal muscle. This observation supports the hypothesis that there may be a block in the biochemical maturation and development of dystrophic muscle after hatching. Free 3-methylhistidine (nmol/g wet wt.) was elevated in dystrophic muscle, whereas blood 3-methylhistidine concentrations were similar in both lines. In summary, the increased myofibrillar protein catabolism demonstrated in dystrophic pectoral muscle correlates with the increased lysosomal cathepsin activity in this tissue as reported by others.

BIOCHEMICAL CHANGES IN PROGRESSIVE MUSCULAR DYSTROPHY: VI. INCORPORATION OF URIDINE-2-14C INTO RNA OF VARIOUS TISSUE OF NORMAL AND DYSTROPHIC MICE

1967 ◽  
Vol 45 (9) ◽  
pp. 1419-1425 ◽  
Author(s):  
Uma Srivastava
Keyword(s):  
Muscular Dystrophy ◽  
Soluble Fraction ◽  
Normal Liver ◽  
Biochemical Changes ◽  
Normal Muscle ◽  
Dystrophic Muscle ◽  
Progressive Muscular Dystrophy ◽  
Dystrophic Mice

Normal and dystrophic mice were injected intravenously with uridine-2-14C at various stages of the disease. Radioactivity in the acid-soluble fraction of most of the tissues studied was unchanged or not significantly different in dystrophic animals. In vivo incorporation of uridine-2-14C into RNA increased in dystrophic muscle as compared to normal muscle at 30 days, remained the same at 60 days, and was reduced at 90 days. Similar results were also observed on the in vitro incorporation of uridine-2-14C catalyzed by homogenates of normal and dystrophic muscle. Dystrophic brain and pancreas showed a decrease in the incorporation at each stage investigated as compared to controls. No change in the incorporation was noted in dystrophic and normal liver, kidney, spleen, and heart. The decrease in uridine-2-14C incorporation in dystrophic muscle at 90 days could be due to an increased RNA content. Such a phenomenon was explained as due to infiltration of dystrophic muscle by invading macrophages.It is concluded that the metabolism of RNA is not decreased in the dystrophic muscle in preliminary stages of the disease as compared to the control.

scholarly journals Rates of protein turnover in vivo and in vitro in ventricular muscle of hearts from fed and starved rats

1984 ◽  
Vol 222 (2) ◽  
pp. 395-400 ◽  
Author(s):  
V R Preedy ◽  
D M Smith ◽  
N F Kearney ◽  
P H Sugden
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Protein Turnover ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Ventricular Muscle ◽  
Degradation Rates ◽  
Perfused Hearts

Starvation of 300 g rats for 3 days decreased ventricular-muscle total protein content and total RNA content by 15 and 22% respectively. Loss of body weight was about 15%. In glucose-perfused working rat hearts in vitro, 3 days of starvation inhibited rates of protein synthesis in ventricles by about 40-50% compared with fed controls. Although the RNA/protein ratio was decreased by about 10%, the major effect of starvation was to decrease the efficiency of protein synthesis (rate of protein synthesis relative to RNA). Insulin stimulated protein synthesis in ventricles of perfused hearts from fed rats by increasing the efficiency of protein synthesis. In vivo, protein-synthesis rates and efficiencies in ventricles from 3-day-starved rats were decreased by about 40% compared with fed controls. Protein-synthesis rates and efficiencies in ventricles from fed rats in vivo were similar to values in vitro when insulin was present in perfusates. In vivo, starvation increased the rate of protein degradation, but decreased it in the glucose-perfused heart in vitro. This contradiction can be rationalized when the effects of insulin are considered. Rates of protein degradation are similar in hearts of fed animals in vivo and in glucose/insulin-perfused hearts. Degradation rates are similar in hearts of starved animals in vivo and in hearts perfused with glucose alone. We conclude that the rates of protein turnover in the anterogradely perfused rat heart in vitro closely approximate to the rates in vivo in absolute terms, and that the effects of starvation in vivo are mirrored in vitro.

Lipid Composition and Synthesis in the Muscles of Normal and Dystrophic Chickens

1972 ◽  
Vol 50 (12) ◽  
pp. 1267-1272 ◽  
Author(s):  
Lee Foon Chio ◽  
D. W. Peterson ◽  
F. H. Kratzer
Keyword(s):  
New Hampshire ◽  
Pectoral Muscle ◽  
Acetate Incorporation ◽  
Total Lipids ◽  
Normal Muscle ◽  
Dystrophic Muscle ◽  
Wet Weight ◽  
The Difference ◽  
Layer Chromatography

The lipids of the superficial pectoral muscle of 5-week-old normal and dystrophic New Hampshire chickens were fractionated by thin-layer chromatography procedures. Total lipid in the dystrophic muscle was fivefold greater than in normal muscle with the triglycerides 15-fold greater and the phospholipids 1.5-fold greater (wet weight basis). The relative proportions of phospholipids were quite similar except for significantly less phosphatidylcholine and phosphatidic acid in the dystrophic muscle. In another study acetate-2-14C was injected intraperitoneally into normal and dystrophic chickens which were killed at various times up to 7 days after the administration. The dystrophic birds incorporated acetate-2-14C to a greater extent into total lipids, triglycerides, and phospholipids of the muscle than normal chickens. The turnover times for both triglycerides and phospholipids were much greater in dystrophic than in normal chickens with the triglycerides showing a longer time than the phospholipids. In vitro incubation of acetate-2-14C with muscle slices showed a greater rate of incorporation into lipid by dystrophic than by normal muscle. These results indicate that the difference in acetate incorporation between normal and dystrophic muscle was due to metabolism in the muscle itself and not entirely a result of mobilization of lipid from other tissues.

scholarly journals In Vitro Kinetic Analysis of Fermentation of Prebiotic Inulin-Type Fructans by Bifidobacterium Species Reveals Four Different Phenotypes

2008 ◽  
Vol 75 (2) ◽  
pp. 454-461 ◽  
Author(s):  
Gwen Falony ◽  
Katerina Lazidou ◽  
An Verschaeren ◽  
Stefan Weckx ◽  
Dominique Maes ◽  
...  
Keyword(s):  
Lactate Production ◽  
Principal Component ◽  
Data Sets ◽  
Strain Specificity ◽  
Carbohydrate Consumption ◽  
Breakdown Mechanism ◽  
High Fructose ◽  
Degradation Rates

ABSTRACT Kinetic analyses of bacterial growth, carbohydrate consumption, and metabolite production of 18 Bifidobacterium strains grown on fructose, oligofructose, or inulin were performed. A principal component analysis of the data sets, expanded with the results of a genetic screen concerning the presence of a β-fructofuranosidase gene previously encountered in Bifidobacterium animalis subsp. lactis DSM 10140T, revealed the existence of four clusters among the bifidobacteria tested. Strains belonging to a first cluster could not degrade oligofructose or inulin. Strains in a second cluster could degrade oligofructose, displaying a preferential breakdown mechanism, but did not grow on inulin. Fructose consumption was faster than oligofructose degradation. A third cluster was composed of strains that degraded all oligofructose fractions simultaneously and could partially break down inulin. Oligofructose degradation was substantially faster than fructose consumption. A fourth, smaller cluster consisted of strains that shared high fructose consumption and oligofructose degradation rates and were able to perform partial breakdown of inulin. For all strains, a metabolic shift toward more acetate, formate, and ethanol production, at the expense of lactate production, was observed during growth on less readily fermentable energy sources. No correlation between breakdown patterns and the presence of the β-fructofuranosidase gene could be detected. These variations indicate niche-specific adaptation of bifidobacteria and could have in vivo implications on the strain specificity of the stimulatory effect of inulin-type fructans on bifidobacteria.

scholarly journals Lactate secreted by PKM2 upregulation promotes Galectin-9-mediated immunosuppression via inhibiting NF-κB pathway in HNSCC

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Hanyue Chang ◽  
Qiaoshi Xu ◽  
Jiayi Li ◽  
Mingyu Li ◽  
Zhiyuan Zhang ◽  
...  
Keyword(s):  
Critical Role ◽  
Lactate Production ◽  
Metabolic Reprogramming ◽  
Migration And Invasion ◽  
Histone Deacetylase 3 ◽  
Proliferation And Metastasis ◽  
Immunosuppressive Microenvironment ◽  
Transcriptional Complex

AbstractPyruvate kinase M2 as a key rate-limiting enzyme in glycolysis, it plays a critical role in metabolic reprogramming and carcinogenesis. However, whether PKM2 can promote immunosuppressive microenvironment formation remains unknown in head and neck squamous cell carcinoma (HNSCC). PKM2 expression was detected using immunohistochemical staining. The biological functions of PKM2 were investigated in vitro and in vivo. Lactate production and the expression of Galectin-9, a critical immunosuppression molecule, were detected after PKM2 knockdown and overexpression in HNSCC cells. The mechanism of lactate regulating Galectin-9 expression through NF-κB signaling was explored in vitro. Overexpression of PKM2 correlates with poor prognosis in HNSCC patients. Silencing PKM2 markedly inhibits proliferation and metastasis capacity in vivo and in vitro, and vice versa. The glycolysis and glycolytic capacity are significantly decreased after PKM2 silencing. Lactate secretion induced by PKM2 significantly promotes migration and invasion capacity. Furthermore, a positive correlation between PKM2 and Galectin-9 expression is observed in HNSCC tissues. The induction of Galectin-9 expression by PKM2 can be affected by a lactate transporter inhibitor. Mechanically, lactate impeded the suppressive transcriptional complex formation of NF-κB and histone deacetylase 3 (HDAC3), which released the transcription of Galectin-9 mediated by NF-κB signaling. Our findings demonstrate that lactate produced by PKM2 upregulation promotes tumor progression and Galectin-9-mediated immunosuppression via NF-κB signaling inhibition in HNSCC, which bridges metabolism and immunosuppression. The novel PKM2-lactate-Galectin-9 axis might be a potential therapeutic target in HNSCC.

Turnover of total proteins and ornithine aminotransferase during liver regeneration in rats

1980 ◽  
Vol 238 (1) ◽  
pp. E46-E52
Author(s):  
S. L. Augustine ◽  
R. W. Swick
Keyword(s):  
Amino Acids ◽  
Liver Regeneration ◽  
Protein Degradation ◽  
Partial Hepatectomy ◽  
Free Amino ◽  
Liver Protein ◽  
Ornithine Aminotransferase ◽  
Fractional Rate

The recovery of approximately 40% of the total liver protein during the first day after partial hepatectomy was shown to be due to the near cessation of protein breakdown rather than to an increase in protein synthesis. The decrease in degradation of total protein was less if rats were adrenalectomized or protein-depleted prior to partial hepatectomy. The effect of these treatments originally suggested that changes in free amino acid levels in liver might be related to the rate of protein degradation. However, no correlation was found between levels of total free amino acids and rates of breakdown. Measurements of individual amino acids during liver regeneration suggested that levels of free methionine and phenylalanine, amino acids that have been found to lower rates of protein degradation in vitro, are not correlated with rates of breakdown in vivo. The difference between the fractional rate of ornithine aminotransferase degradation (0.68/day and 0.28/day in sham-hepatectomized and partially hepatectomized rats, respectively) was sufficient to account for the higher level of this protein 3 days after surgery in the latter group.

Reproduction in Aplysia californica: correlations between egg laying in vivo and egg release in vitro

1980 ◽  
Vol 58 (11) ◽  
pp. 2163-2166 ◽  
Author(s):  
F. Edward Dudek ◽  
Amd Bonnie Soutar ◽  
Stephen S. Tobe
Keyword(s):  
Aplysia Californica ◽  
Egg Laying ◽  
Previous Episode ◽  
Laboratory Conditions ◽  
Release In Vitro

Aspects of egg laying by isolated Aplysia californica and egg release from ovotestis fragments were compared under laboratory conditions. The volume of eggs laid per episode increased as a function of time since the previous episode of egg laying. Egg output in vivo and egg release in vitro were maximal in autumn and minimal in spring, but a factor in the parietovisceral ganglion evoked egg release from ovotestis fragments throughout the year. These data are consistent with previous studies which have suggested that the effects of season and egg-laying history on egg laying involve substantial changes in the ovotestis.

Sign in / Sign up

Export Citation Format

Share Document