INTRODUCTION Treadmill training is known to prevent muscle atrophy after spinal cord injury (SCI), but the training duration required to optimize recovery has not been investigated. METHODS Hemisected mice were randomized to 3, 6, or 9 weeks of training or no training. Muscle fiber type composition and fiber cross-sectional area (CSA) of medial gastrocnemius (MG), soleus (SOL), and tibialis a...

Fiber type specificity of pyruvate dehydrogenase (PDH) phosphatase (PDP) was determined in fed (CON) and 48-h food-deprived (FD) rats. PDP activity and isoform protein content were determined in soleus (slow-twitch oxidative), red gastrocnemius (RG; fast-twitch oxidative glycolytic), and white gastrocnemius (WG; fast-twitch glycolytic) muscles. When normalized for mitochondrial volume, there wa...

Skeletal muscles show a high plasticity to cope with various physiological demands. Different muscle types can be distinguished by the force, endurance, contraction/relaxation kinetics (fast-twitch vs. slow-twitch muscles), oxidative/glycolytic capacity, and also with respect to Ca²⁺-signaling components. Changes in Ca²⁺ signaling and associated Ca²⁺-dependent processes are thought to underlie ...

Muscle fiber composition correlates with insulin resistance, and exercise training can increase slow-twitch (type I) fibers and, thereby, mitigate diabetes risk. Human skeletal muscle is made up of three distinct fiber types, but muscle contains many more isoforms of myosin heavy and light chains, which are coded by 15 and 11 different genes, respectively. Laser capture microdissection techniqu...

BACKGROUND Significant consequences of severe burn include skeletal muscle atrophy and heterotopic ossification (HO). The cellular mechanisms underlying either of these conditions are not known. Whether the functionality of satellite cells stem cells resident in skeletal muscle is affected by changes in circulatory factors following burn was determined to better understand their role in atrophy...

Medical issues in manned spaceflight fall into several broad categories. One of the most dramatic effects is in the musculoskeletal system, where the abrupt loss of weight bearing leads to dramatic wasting of the gravity bearing muscles (legs and back) and a gradual conversion of slow twitch fibers to fast twitch fibers. This leads to reduction in force generation and the need for greater neura...

I’ERJUNG, R. L., K. M. BALIX~~N, W. W. WINDER, AND J. Q. HOLLOSZY. GLycogen repletion in cli$erent types of muscle and in Iiver ufter exhausting exercise. Am. J. Physiol. 226(6): 1387-1391. 1974.Glycogen repletion rates in fast-twitch red, slow-twitch red, and fast-twitch white types of skeletal muscle, in heart, and in liver were compared in rats after depletion of glycogen stores by exercise....

Skeletal muscles of teleost are mainly composed slow-twitch (SM) and fast-twitch (FM) differed in contractile properties, metabolic capacities, regeneration rate. The transcriptional regulatory mechanisms that control different muscle types have been elucidated according to transcriptome between SM FM. However, the differences FM were affected not only by genotype but also complicated epigeneti...

A robust infrastructure for solving time-dependent diffusion using the finite element package FEtk has been developed to simulate synaptic transmission in a neuromuscular junction with realistic postsynaptic folds. Simplified rectilinear synapse models serve as benchmarks in initial numerical studies of how variations in geometry and kinetics relate to endplate currents associated with fast-twi...

Denervation induces skeletal muscle atrophy, which primarily impairs oxidative slow twitch fibers. The underlying mechanism of this phenomenon, however, remains to be addressed. We hypothesize that denervation-induced fiber-specific atrophy may result from the distinct activities of different signaling pathways that are involved in protein synthesis and degradation in fast- and slow-twitch fibe...