Rates of protein synthesis in skin and bone, and their importance in the assessment of protein degradation in the perfused rat hemicorpus.
Ontology highlight
ABSTRACT:
SUBMITTER: Preedy VR
PROVIDER: S-EPMC1162755 | biostudies-other | 1981 Jan
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Increasing the extracellular pH over the range pH 7.4-8.9 stimulated protein synthesis by about 60% in the rat heart preparation anterogradely perfused in vitro. Protein degradation was inhibited by this pH increase. The magnitudes of the effects at pH 8.9 on protein synthesis and degradation were similar to those of high concentrations of insulin. Cardiac outputs were increased, as were cardiac phosphocreatine contents, indicating that the alterations in extracellular pH did not adversely affect the physiological viability of the preparation. ATP contents were unaltered. The creatine kinase equilibrium was used to assess the magnitude of the change in intracellular pH induced by these treatments. The increase in intracellular pH was about 0.2 for a 1-unit increase in extracellular pH. Thus small changes in intracellular pH have dramatic effects on cardiac protein turnover.
| S-EPMC1138488 | biostudies-other
Project description:The effect of hypophysectomy on the protein metabolism of the liver in vivo was studied. Fractional rates of protein synthesis and degradation were determined in the livers of normal and hypophysectomized rats. Synthesis was measured after the injection of massive amounts of radioactive leucine. Degradation was estimated either as the balance between synthesis and accumulation of stable liver proteins or from the disappearance of radioactivity from the proteins previously labelled by the injection of NaH14CO3. The results indicate that: (1) hypophysectomy diminishes the capacity of the liver to synthesize proteins in vivo, mainly of those that are exported as plasma proteins; (2) livers of both normal and hypophysectomized rats show identical protein-degradation rates, whereas plasma proteins are degraded slowly after hypophysectomy.
| S-EPMC1186573 | biostudies-other
Project description:Spontaneous Raman spectroscopy, which senses changes in cellular contents of reduced cytochrome c, could be a powerful tool for label-free evaluation of ischemic hearts. However, undetermined is whether it is applicable to evaluation of myocardial viability in ischemic hearts. To address this issue, we investigated sequential changes in Raman spectra of the subepicardial myocardium in the Langendorff-perfused rat heart before and during ligation of the left coronary artery and its subsequent release and re-ligation. Under 532-nm wavelength excitation, the Raman peak intensity of reduced cytochrome c at 747 cm-1 increased quickly after the coronary ligation, and reached a quasi-steady state within 30 min. Subsequent reperfusion of the heart after a short-term (30-min) ligation that simulates reversible conditions resulted in quick recovery of the peak intensity to the baseline. Further re-ligation resulted in resurgence of the peak intensity to nearly the identical value to the first ischemia value. In contrast, reperfusion after prolonged (120-min) ligation that assumes irreversible states resulted in incomplete recovery of the peak intensity, and re-ligation resulted in inadequate resurgence. Electron microscopic observations confirmed the spectral findings. Together, the Raman spectroscopic measurement for cytochrome c could be applicable to evaluation of viability of the ischemic myocardium without labeling.
| S-EPMC8116620 | biostudies-literature
Project description:The rate of protein synthesis was measured in muscles of the perfused rat hemicorpus, and values were compared with rates obtained in whole animals. In gastrocnemius muscle of fed rats the rate of synthesis measured in the hemicorpus was the same as that in the whole animal. However, in plantaris, quadriceps and soleus muscles rates were higher in the hemicorpus than those in vivo. In the hemicorpus, starvation for 1 day decreased the rate of protein synthesis in gastrocnemius and plantaris muscles, in parallel with decreases in the RNA content, but the soleus remained unaffected. Similar effects of starvation were observed in vivo, so that the relationships between rates in vivo and in the hemicorpus were the same as those in fed rats. Proteins of quadriceps and plantaris muscles were separated into sarcoplasmic and myofibrillar fractions. The rate of synthesis in the sarcoplasmic fraction of the hemicorpus from fed rats was similar to that in vivo, but synthesis in the myofibrillar fraction was greater. In the plantaris of starved rats the rates of synthesis in both fractions were lower, but the relationships between rates measured in vivo and in the perfused hemicorpus were similar to those seen in fed rats. The addition of insulin to the perfusate of the hemicorpus prepared from 1-day-starved animals increased the rates of protein synthesis per unit of RNA in gastrocnemius and plantaris muscles to values above those seen in fed animals when measured in vivo or in the hemicorpus. Insulin had no effect on the soleus. Overall, the rates of protein synthesis in the hemicorpus differed from those in vivo. However, the effect of starvation when measured in the whole animal was very similar to that measured in the isolated rat hemicorpus when insulin was omitted from the perfusate.
| S-EPMC1152264 | biostudies-other
Project description:Rates of muscle protein synthesis and degradation measured in the perfused hindquarter were compared with those in incubated epitrochlearis muscles. With fed or starved mature rats, results without insulin treatment were identical. With insulin treatment, protein synthesis in perfused hindquarters was greater, though protein degradation was the same. Thus rates of muscle protein degradation estimated by these two methods in vitro correspond closely.
| S-EPMC1153139 | biostudies-other
Project description:Measures of perfusion adequacy in perfused rat hemicorpus preparations were investigated as potential indices of tissue function during studies of muscle protein metabolism. Perfusion under normal conditions for up to 80 min resulted in rates of protein synthesis and concentrations of ATP in muscle that were similar to those in vivo, but phosphocreatine in muscle gradually decreased and muscle lactate increased. Hypoxic conditions led to lower rates of protein synthesis, lower phospho-creatine and raised lactate contents in muscle compared with normal perfusions, and ATP was slightly decreased. Hypoxic preparations also released more lactate and K+ into the medium and had higher perfusion pressures, but glucose uptake and muscle water content were not altered. In totally ischaemic muscle, concentrations of ATP and phosphocreatine were even lower than in hypoxic muscle, and that of lactate was higher. From 11 preparations perfused for 60 min under normal conditions, three were selected on the basis of lower muscle ATP content than the others. Preparations with low ATP also showed lower muscle phosphocreatine concentrations, O2 uptake and CO2 output, as well as higher perfusion pressure and muscle lactate concentrations than in the remaining preparations, but muscle water, ADP and AMP concentrations and lactate and K+ flux were no different. In perfusions extended to 3 h, deterioration of function was more apparent. There were significant correlations between rates of protein synthesis and the concentrations of ATP, phosphocreatine and lactate in two different muscles (r = 0.756-0.929), but not with any of the other indices investigated. Taken overall, these experiments showed that concentrations of ADP, AMP and water in muscle, rates of lactate and glucose metabolism, K+ output, perfusion pressure and blood gas parameters were unsuitable for distinguishing unsound from sound preparations, because they did not consistently demonstrate differences, or could not be ascribed to only muscle metabolism. It was found that ATP, phosphocreatine and lactate concentrations in muscle were the best indicators of impaired metabolic state in studies of protein synthesis. Measurements of these could be used on a routine basis for rejecting unsatisfactory preparations.
| S-EPMC1153357 | biostudies-other
Project description:Protein-degradation rates in developing rat brain were estimated from the decay in total radioactivity in proteins labelled by a single intraperitoneal injection of NaH14CO3 to 5-day-old animals. In contrast with previous reports, our results indicate that degradation rates are lower in developing than in adult brain and suggest that in brain, as has been observed in liver, adrenal gland, muscle, cultured mammalian cells and bacteria, reduced rates of protein degradation contribute to the increase in protein content under conditions of rapid growth.
| S-EPMC1161067 | biostudies-other
Project description:A quantitative view of cellular functions requires precise measures of the rates of biomolecule production, especially proteins-the direct effectors of biological processes. Here we present a genome-wide approach, based on ribosome profiling, for measuring absolute protein synthesis rates. The resultant E. coli dataset transforms our understanding of the extent to which protein synthesis is precisely controlled to optimize function and efficiency. For example, members of multi-protein complexes are made in precise proportion to their stoichiometry, whereas components of functional modules are produced differentially according to their hierarchical role. Estimates of absolute protein abundance also reveal principles used to optimize design. These include how the level of different types of transcription factors is optimized for rapid response, and how a metabolic pathway (methionine biosynthesis) balances production cost with activity requirements. More broadly, our studies reveal how general principles, important both for understanding natural systems and for synthesizing new ones, emerge from global quantitative analyses of protein synthesis. 4 samples of E. coli ribosome profiling and mRNA-seq, including biological replicates
2014-04-24 | E-GEOD-53767 | biostudies-arrayexpress
Project description:Within individual species and cell types, the range of protein turnover rates can span multiple orders of magnitude. However, it is not known if turnover kinetics of individual proteins are highly conserved or if they have evolved to meet the physiological demands of individual species. We have conducted systematic analyses of proteome turnover kinetics in primary dermal fibroblasts isolated from eight different rodent species. Our results demonstrate that protein turnover rates are generally well conserved across species but gradually deviate as a function of evolutionary distance.
2018-02-07 | PXD007598 | Pride
Project description:A quantitative view of cellular functions requires precise measures of the rates of biomolecule production, especially proteins-the direct effectors of biological processes. Here we present a genome-wide approach, based on ribosome profiling, for measuring absolute protein synthesis rates. The resultant E. coli dataset transforms our understanding of the extent to which protein synthesis is precisely controlled to optimize function and efficiency. For example, members of multi-protein complexes are made in precise proportion to their stoichiometry, whereas components of functional modules are produced differentially according to their hierarchical role. Estimates of absolute protein abundance also reveal principles used to optimize design. These include how the level of different types of transcription factors is optimized for rapid response, and how a metabolic pathway (methionine biosynthesis) balances production cost with activity requirements. More broadly, our studies reveal how general principles, important both for understanding natural systems and for synthesizing new ones, emerge from global quantitative analyses of protein synthesis.
2014-04-24 | GSE53767 | GEO