Fasting elicits a progressive increase in lipid metabolism within skeletal muscle. To determine the effects of fasting on the transcriptional regulation of genes important for metabolic control in skeletal muscle composed of different fiber types, nuclei from control and fasted (24 and 72 h) rats were subjected to nuclear run-on analysis using an RT-PCR-based technique. Fasting increased (P < 0...

Moderate physical activity increases antioxidant defenses, whereas intensive activity is associated with oxidative stress. In this study we investigated the expression of superoxide dismutase (Cu,Zn-SOD), a major antioxidant defense enzyme, and that of the proteolytic enzyme matrix metalloproteinase-2 (MMP-2) in exercising muscle tissue. Treadmill running was used as a model to investigate the ...

Most mammals possess stamina because their locomotor and respiratory (i.e., ventilatory) systems are mechanically coupled. These systems are decoupled, however, in bottlenose dolphins (Tursiops truncatus) as they swim on a breath hold. Locomotion and ventilation are coupled only during their brief surfacing event, when they respire explosively (up to 90% of total lung volume in approximately 0....

Purpose We tested the hypothesis that short-term treatment with brain derived neurotrophic factor (BDNF) would alter the contractile characteristics of rabbit extraocular muscle (EOM). Methods One week after injections of BDNF in adult rabbit superior rectus muscles, twitch properties were determined in treated and control muscles in vitro. Muscles were also examined for changes in mean cross...

Cranial skeletal muscles underlie breathing, eating, and eye movements. In most animals, at least two types of muscle fibers underlie these critical functions: fast and slow muscle fibers. We describe here the anatomical distribution of slow and fast twitch muscle in the zebrafish (Danio rerio) head in the adult and at an early larval stage just after feeding has commenced. We found that all bu...

The aim of the present study was to examine the influence of intermittent hypoxia at rest and in combination with long-term high-intensity swimming exercise on lipid peroxidation and antioxidant defense system adaptation in skeletal muscles differing in fiber type composition. High-intensity chronic exercise was performed as swimming training with load that corresponded to ~ 75 % VO2max (30 min...

A decreased exercise tolerance is a common symptom in patients with congestive heart failure (CHF). This decrease has been suggested to be partly due to altered skeletal muscle function. Therefore, we have studied contractile function and cytoplasmic free Ca(2+) concentration ([Ca(2+)](i), measured with the fluorescent dye indo 1) in isolated muscles from rats in which CHF was induced by ligati...

A decreased exercise tolerance is a common symptom in patients with congestive heart failure (CHF). This decrease has been suggested to be partly due to altered skeletal muscle function. Therefore, we have studied contractile function and cytoplasmic free Ca concentration ([Ca]i, measured with the fluorescent dye indo 1) in isolated muscles from rats in which CHF was induced by ligation of the ...

In this study, the fiber type specificity of dihydropyridine receptors (DHPRs) and ryanodine receptors (RyRs) in different rat limb muscles was investigated. Western blot and histochemical analyses provided for the first time evidence that the expression of both receptors correlates to a specific myosin heavy chain (MHC) composition. We observed a significant (p=0.01) correlation between DHP as...