Receptor-activator of nuclear factor-κB (RANK), its ligand RANKL, and the soluble decoy receptor osteoprotegerin are the key regulators of osteoclast differentiation and bone remodeling. Here we show that RANK is also expressed in fully differentiated myotubes and skeletal muscle. Muscle RANK deletion has inotropic effects in denervated, but not in sham, extensor digitorum longus (EDL) muscles ...

The composition of skeletal muscle, in terms of the relative number of slow- and fast-twitch fibers, is tightly regulated to enable an organism to respond and adapt to changing physical demands. The phosphatase calcineurin and its downstream targets, transcription factors of the nuclear factor of activated T cells (NFAT) family, play a critical role in this process by promoting the formation of...

BACKGROUND Peripheral nerve injury (PNI) rehabilitation remains a challenge for physical therapists because PNI effects are very disabling. Low-level laser therapy (LLLT) has been described as a physical resource that is able to influence enzymes called metallopeptidases (MMPs) associated with extracellular matrix (ECM) turnover, thus accelerating neuromuscular recovery after nerve crush injuri...

Aerobic Power (VO2 max) and anaerobic power were estimated in medical students before and after six weeks of yogic training. A significant increase in aerobic power and a significant decrease in anaerobic power was observed. This may be due to conversion of some of the Fast Twitch (F.T.) muscle fibres into Slow Twitch fibres (S.T.) during yogic training.

Skeletal muscle weakness and decreased exercise capacity are major symptoms reported by patients with congestive heart failure (CHF). Intriguingly, these skeletal muscle symptoms do not correlate with the decreased heart function. This suggests that CHF leads to maladaptive changes in skeletal muscles, and as reported most markedly in slow-twitch muscles. We used rats at 6 weeks after infarctio...

BACKGROUND Cutaneous burn distant from skeletal muscles induces atrophy; however, its effect on muscle stem cells resident in skeletal muscle (satellite cells) distal to burn is not known. METHODS Satellite cell activation was measured in predominantly fast-twitch [tibialis anterior, extensor digitorum longus (EDL), plantaris, and gastrocnemius] and slow-twitch (soleus) muscles of rats that r...

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...

The accumulation of covalently modified proteins is an important hallmark of biological aging, but relatively few studies have addressed the detailed molecular-chemical changes and processes responsible for the modification of specific protein targets. Recently, Narayanan et al. [Narayanan, Jones, Xu and Yu (1996) Am. J. Physiol. 271, C1032-C1040] reported that the effects of aging on skeletal-...

The fact that humans possess fast- and slow-twitch muscle in the ratio of ∼50% has profound implications for designing exercise training strategies for power and endurance activities. With the growth of exercise and sport science courses, we have seen the need to develop an undergraduate student laboratory that demonstrates the basic properties of fast- and slow-twitch mammalian skeletal muscle...