A divergent selection experiment was conducted for 8-wk BW in chickens. At 3, 6, 9, and 12 wk of age, samples of pectoralis profundus (PP) and biceps femoris (BF) muscles from fast-growing and slow-growing lines were used to estimate the enzyme activities and muscle fiber diameter. Microphotometric measurements made in situ of succinate dehydrogenase (SDH, EC 1.3.99.1) and glycerol-3-phosphate dehydrogenase (GPDH, EC 1.1.99.5) were completed on serial sections of PP and BF muscles from male chickens, in order to examine the ratio of SDH:GPDH activity in single fibers. On the basis of the SDH:GPDH activity ratios, muscle fibers were divided using cluster analysis into 3 populations of different fiber types (O = oxidative, OG = oxidative-glycolytic, and G = glycolytic). Cockerels of the SGL attained an 8.1-fold increase and those of the FGL a 6.8-fold increase in BW at 12 wk compared with that at 3 wk of age. The O, OG, and G type fibers of the BF muscles of the SGL had significantly (P ≤ 0.001) lower SDH:GPDH activity ratios than those of the FGL. A step decrease in the SDH:GPDH activity of O, OG, and G fibers in the PP of both lines occurred, and this differed significantly between SGL and FGL (P ≤ 0.001). Age and line effects influenced the diameter of the 3 fiber types in the BF muscle only. In contrast to this response, all 3 fiber types of the PP muscles reached similar diameters in both lines during the growth process from wk 3 to 12. From the results of this study, we concluded that the activities of metabolic enzymes in skeletal muscle fibers are under the influence of muscle type, age, and selection pressure. Microphotometry is a suitable method for the evaluation of enzyme activity measured in a single muscle fiber. The method enables precise estimation of enzyme activities, especially in muscles composed of populations of different metabolic fiber types.
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http://dx.doi.org/10.3382/ps.2010-00641 | DOI Listing |
PLoS Pathog
January 2025
Department of Clinical Microbiology, Umeå University, Umeå, Sweden.
Human adenovirus type 36 (HAdV-D36) has been putatively linked to obesity in animals and has been associated with obesity in humans in some but not all studies. Despite extensive epidemiological research there is limited information about its receptor profile. We investigated the receptor portfolio of HAdV-D36 using a combined structural biology and virology approach.
View Article and Find Full Text PDFJ Neurosci
January 2025
Department of Neuroscience, Brown University, Providence RI, USA.
Voltage-gated potassium conductances [Formula: see text] play a critical role not only in normal neural function, but also in many neurological disorders and related therapeutic interventions. In particular, in an important animal model of epileptic seizures, 4-aminopyridine (4-AP) administration is thought to induce seizures by reducing [Formula: see text] in cortex and other brain areas. Interestingly, 4-AP has also been useful in the treatment of neurological disorders such as multiple sclerosis (MS) and spinal cord injury, where it is thought to improve action potential propagation in axonal fibers.
View Article and Find Full Text PDFExp Gerontol
January 2025
School of Food and Bioengineering, Xihua University, Chengdu 610039, China.
Purpose: The study aims to investigate the therapeutic effects of the aqueous extract of Atractylodes macrocephala Koidz. (AEA) on dexamethasone (Dex) -induced sarcopenia in mice and to explore its possible mechanisms of action.
Methods: This study utilized bioinformatics analysis to explore the primary pathogenic mechanisms of age-related sarcopenia and Dex-induced muscle atrophy.
Asian Pac Isl Nurs J
January 2025
Nursing Care Research Center, Clinical Sciences Institute, Nursing Faculty, Baqiyatallah University of Medical Sciences, Vanak Square, Tehran, Iran, 98 9127297199.
Background: Neuromuscular disorders (NMDs) constitute a heterogeneous group of disorders that affect motor neurons, neuromuscular junctions, and muscle fibers, resulting in symptoms such as muscle weakness, fatigue, and reduced mobility. These conditions significantly affect patients' quality of life and impose a substantial burden on caregivers. Spinal muscular atrophy (SMA) is a relatively common NMD in children that presents in various types with varying degrees of severity.
View Article and Find Full Text PDFCell Physiol Biochem
January 2025
Department of Animal Physiology, Biochemistry and Biostructure, Poznan University of Life Sciences, Poznan, Poland,
Background/aims: MOTS-c belongs to a group of mitochondrial peptides involved in metabolic processes in the body. This peptide has garnered increasing attention since its discovery in 2015 because of its potential to ameliorate metabolic parameters in animals with diabetes or insulin resistance. MOTS-c is involved in muscle metabolism; however, little is known about its role in fiber differentiation.
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