In addition to showing differences in the levels of contractile proteins and metabolic enzymes, fast and slow muscles also differ in their expression profile of structural and synaptic proteins. Because utrophin is a structural protein expressed at the neuromuscular junction, we hypothesize that its expression may be different between fast and slow muscles. Western blots showed that, compared w...

conclusions these results showed enhanced muscle atrophy processes following peripheral nerve damage and might provide a useful approach to study underlying muscle mechanisms associated with clinical neuropathic pain syndromes. results compared to control animals, l5 ligated animals developed mechanical and heat hypersensitivity during total period of study. soleus muscle weight as well as cdk5...

This study was designed to determine whether the reductions in GLUT-4 seen in 3-day-denervated muscles can be prevented through chemical activation of 5'-AMP-activated protein kinase (AMPK). Muscle AMPK can be chemically activated in rats using subcutaneous injections with 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR). In this study, the tibial nerve was sectioned on one side; ...

We have studied the effect of chronic thyroid status alterations on the myosin heavy chain (MyHC) isoform composition (by SDS-PAGE) and on MyHC mRNA levels (by RT-PCR) in the fast extensor digitorum longus (EDL) muscle of 7-month-old inbred Lewis strain female rats and compared this with corresponding results of the previously studied slow soleus muscle. Our findings show that in the EDL muscle...

PURPOSE αB-crystallin is a small heat shock protein that acts as a molecular chaperone under various stress conditions. Microtubules, which consist of tubulin, are related to maintain the intracellular organelles and cellular morphology. These two proteins have been shown to be related to the properties of different types of myofibers based on their contractile properties. The response of these...

We examined the mechanism of accelerated proteolysis in denervated rat soleus muscles. The soleus was denervated by severing either the tibial nerve (proximal, short stump) or sciatic nerve (distal, long stump) at 24, 48, 72, or 96 h before excision. Twenty-four hours after denervation, the extent of atrophy was similar for proximal and distal denervation, although lysosomal latency declined in...

During chronic obstructive pulmonary disease (COPD) diaphragm and peripheral muscle weakness occur. Muscle remodeling and wasting may be a result of apoptosis and changes in muscle-specific transcription factors, such as MyoD, altering muscle-specific gene transcription and muscle regenerative capacity. To investigate this, we instilled under ketamine/xylazine anesthesia porcine elastase in the...

This study was undertaken in order to provide further insight into the role of leucine supplementation in the skeletal muscle regeneration process, focusing on myofiber size and strength recovery. Young (2-month-old) rats were subjected or not to leucine supplementation (1.35 g/kg per day) started 3 days prior to cryolesion. Then, soleus muscles were cryolesioned and continued receiving leucine...

1. Comparisons were made in vitro at 25 degrees C among soleus and extensor digitorum longus (EDL) muscles from young (2-3 months), adult (9-10 months), and aged (26-27 months) male mice. We tested the hypotheses that, compared with soleus and EDL muscles of young and adult mice, those from aged mice develop decreased maximum tetanic force (P0, mN) and specific P0 (N/cm2), and that no significa...

We evaluated the effects of three levels of energy intake, 73 % (CON73), 81 % (CON81) and 100 % (CON100) of the ad libitum intake of the control diet, on skeletal muscle growth induced by functional overload in male rats. Unlike most previous studies which have employed chronic or acute food restriction where all nutrients are reduced in the diet, the present study tested the effects of energy ...