Quantitative importance of non-skeletal-muscle sources of N tau-methylhistidine in urine.
Ontology highlight
ABSTRACT:
SUBMITTER: Millward DJ
PROVIDER: S-EPMC1162081 | biostudies-other | 1980 Jul
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The excretion of N tau-methylhistidine and creatinine was determined in a totally paralysed patient wih neither macroscopic nor microscopic detectable skeletal-muscle tissue. In this subject, it was possible for the first time to measure the basal non-skeletal-muscle-dependent excretion of N tau-methylhistidine and creatinine per 24 h and per kg of non-muscular body weight, 1.15 mumol (N tau-methylhistidine) and 35 mumol (creatinine) respectively. For the calculation of myofibrillar protein breakdown and skeletal-muscle mass on the basis of N tau-methylhistidine and creatinine excretion, the values have to be corrected for non-muscular sources. Our data show that skeletal-muscle tissue is the major contributor of N tau-methylhistidine in urine, since it contributes as much as 75% to the urinary excretion.
| S-EPMC1163557 | biostudies-other
Project description:The claim of Millward, Bates, Grimble, Brown, Nathan & Rennie [(1980) Biochem. J. 190. 225--228] that muscle actomyosin contributes as little as 25% of urinary N tau-methylhistidine is not consistent with other published data from that group [Bates, DeCoster, Grimble, Holloszy, Millward & Rennie (1980) J. Physiol. (London) 303, 41 P] or with literature values. It appears likely that the turnover rate of muscle actomyosin has been considerably underestimated and that when realistic rates of protein turnover are used, muscle tissue remains the major contributor of N tau-methylhistidine in urine.
| S-EPMC1162840 | biostudies-other
Project description:Mice and rats were injected with tracer doses of radioactive N tau-[Me-14C]methylhistidine in order to determine the recovery of the injected radioactivity and the extent of the metabolism of N tau-methylhistidine. In the first 27 h after injection, 96.3, 78.0 and 97.5% of radioactivity was excreted by female mice, male mice and male rats respectively. Recovery after 5 days of collection was 98.4 and 92.8% for female and male mice respectively. However, radioactivity associated with N tau-methylhistidine or its acetylated derivative accounted for 44, 86.5 and 96.0% of the excreted radioactivity for female mice, male mice and rats respectively. In female mice the remaining excreted radioactivity was associated with four major peaks of activity when the metabolites were separated by cation-exchange chromatography. In male mice there were only three of these metabolites present. After chromatographic purification, one metabolite was identified by mass spectroscopy to be 1-methylimidazole-4-acetic acid. Examination of the possible sources of this metabolite indicates that, in mice, N tau-methylhistidine is decarboxylated and enters the chain of reactions common to histamine metabolism. Such extensive metabolism precludes the use of N tau-methylhistidine excretion as an index of myofibrillar protein breakdown in mice.
| S-EPMC1152894 | biostudies-other
Project description:Emerging and promising therapeutic interventions for Duchenne muscular dystrophy (DMD) are confounded by the challenges of quantifying dystrophin. Current approaches have poor precision, require large amounts of tissue, and are difficult to standardize. This paper presents an immuno-mass spectrometry imaging method using gadolinium (Gd)-labeled anti-dystrophin antibodies and laser ablation-inductively coupled plasma-mass spectrometry to simultaneously quantify and localize dystrophin in muscle sections. Gd is quantified as a proxy for the relative expression of dystrophin and was validated in murine and human skeletal muscle sections following k-means clustering segmentation, before application to DMD patients with different gene mutations where dystrophin expression was measured up to 100 µg kg-1 Gd. These results demonstrate that immuno-mass spectrometry imaging is a viable approach for pre-clinical to clinical research in DMD. It rapidly quantified relative dystrophin in single tissue sections, efficiently used valuable patient resources, and may provide information on drug efficacy for clinical translation.
| S-EPMC7806610 | biostudies-literature
Project description:The tissue origin of 3-methylhistidine (N tau-methylhistidine) was investigated in adult female rats. The decay of labelling of urinary 3-methylhistidine was compared with the labelling of protein-bound 3-methylhistidine in skeletal muscle and intestine after the injection of [methyl-14C]methionine. The decay curve for urinary 3-methylhistidine was much steeper than that in muscle or intestine, falling to values lower than those in either tissue after 30 days. The lack of decay of labelling in muscle during the first 30 days is shown to result from the persistence of label in the precursor S-adenosylmethionine. The relative labelling of urinary, skeletal-muscle and intestinal 3-methylhistidine cannot be explained in terms of skeletal muscle accounting for a major proportion of urinary 3-methylhistidine. Measurements were also made of the steady-state synthesis rate of protein-bound 3-methylhistidine in intestinal smooth muscle in vivo in adult female rats. This involved measurement of the overall rate of protein synthesis and measurement of the relative rates of synthesis of 3-methylhistidine and of mixed protein. The synthesis rate of 3-methylhistidine was 29.1%/day, compared with the overall rate of 77.1%/day for mixed, non-mucosal intestinal protein. Measurement of the amount of 3-methylhistidine in skeletal muscle (0.632 +/- 0.024 mumol/g) and in the whole body (0.332 +/- 0.013 mumol/g) indicate that, although the muscle pool is 86% of the total, because of its slow turnover rate of 1.1-1.6%/day, it only accounts for 38-52% of the observed excretion. Measurements of the mass of the intestine (9.95 g/250 g body wt.) and protein-bound 3-methylhistidine content (0.160 mumol/g of tissue) indicate a pool size of 1.59 mumol/250 micrograms rat. Thus 463 nmol of the urinary excretion/day would originate from the intestine, 22% of the total. The tissue source of the remaining urinary excretion is not identified, but other non-muscle sources constituting about 10% of the whole-body pool could account for this with turnover rates of only 6%/day, a much lower value than the turnover rate in the intestine.
| S-EPMC1152287 | biostudies-other
Project description:MuRF1 (TRIM63) is a muscle-specific E3 ubiquitin ligase and component of the ubiquitin proteasome system. MuRF1 is transcriptionally upregulated under conditions that cause muscle loss, in both rodents and humans, and is a recognized marker of muscle atrophy. In this study, we used in vivo electroporation to determine whether MuRF1 overexpression alone can cause muscle atrophy and, in combination with ubiquitin proteomics, identify the endogenous MuRF1 substrates in skeletal muscle. Overexpression of MuRF1 in adult mice increases ubiquitination of myofibrillar and sarcoplasmic proteins, increases expression of genes associated with neuromuscular junction instability, and causes muscle atrophy. A total of 169 ubiquitination sites on 56 proteins were found to be regulated by MuRF1. MuRF1-mediated ubiquitination targeted both thick and thin filament contractile proteins, as well as, glycolytic enzymes, deubiquitinases, p62, and VCP. These data reveal a potential role for MuRF1 in not only the breakdown of the sarcomere but also the regulation of metabolism and other proteolytic pathways in skeletal muscle.
| S-EPMC8218097 | biostudies-literature
Project description:Genetic and biochemical defects of mitochondrial function are a major cause of human disease, but their link to mitochondrial morphology in situ has not been defined. Here, we develop a quantitative three-dimensional approach to map mitochondrial network organization in human muscle at electron microscopy resolution. We establish morphological differences between human and mouse and among patients with mitochondrial DNA (mtDNA) diseases compared to healthy controls. We also define the ultrastructure and prevalence of mitochondrial nanotunnels, which exist as either free-ended or connecting membrane protrusions across non-adjacent mitochondria. A multivariate model integrating mitochondrial volume, morphological complexity, and branching anisotropy computed across individual mitochondria and mitochondrial populations identifies increased proportion of simple mitochondria and nanotunnels as a discriminant signature of mitochondrial stress. Overall, these data define the nature of the mitochondrial network in human muscle, quantify human-mouse differences, and suggest potential morphological markers of mitochondrial dysfunction in human tissues.
| S-EPMC6513570 | biostudies-literature
Project description:We analyzed gene expression in regions from tibialis anterior cross sections of P301L tau expressing mice and controls. The regions were: standard myofibers, regions containing centrally nucleated myofibers, myofibers proximal to nerve bundle, and myofibers proximal to vasculature
2023-11-19 | GSE248201 | GEO
Project description:The metabolism of N tau-[Me-14C]methylhistidine by mice was influenced by both the sex and the phenotype of the animal. After subcutaneous injection of labelled N tau-methylhistidine, recoveries of radioactivity in excreta were incomplete, and the distributions of radioactivity showed that different mouse phenotypes degraded N tau-methylhistidine in vivo to different extents. Hence the excretion of N tau-methylhistidine by mice cannot be used as an index of protein breakdown in vivo.
| S-EPMC1147265 | biostudies-other
Project description:Skeletal muscle is widely perceived as nearly incompressible despite the fact that blood and lymphatic vessels within the endomysial and perimysial spaces undergo significant changes in diameter and length during stretch and contraction. These fluid shifts between fascicle and interstitial compartments have proved extremely difficult to measure. In this paper, we propose a theoretical framework based on a space-filling hexagonal fascicle array to provide predictions of the displacement of blood and lymph into and out of the muscle's endomysium and perimysium during stretch and contraction. We also use this model to quantify the distribution of blood and initial lymphatic (IL) vessels within a fascicle and its perimysial space using data for the rat spinotrapezius muscle. On average, there are 11 muscle fibers, 0.4 arteriole/venule pairs, and 0.2 IL vessels per fascicle. The model predicts that the blood volume in the endomysial space increases 24% and decreases 22% for a 20% contraction and stretch, respectively. However, these significant changes in blood volume in the endomysium produce a change of only ?2% in fascicle cross-sectional area. In contrast, the entire muscle deviates from isovolumetry by 7% and 6% for a 20% contraction and stretch, respectively, largely attributable to the significantly larger blood volume changes that occur in the perimysial space. This suggests that arcade blood vessels in the perimysial space provide the primary pumping action required for the filling and emptying of ILs during muscular contraction and stretch.
| S-EPMC3384164 | biostudies-literature