Skeletal muscle regeneration requires processes different from developmental myogenesis. One important difference is a requirement of inflammatory reactions prior to regenerative myogenesis, by which injured muscle fibers must be eliminated to make new myotubes. In this study, we show that efficient elimination of injured muscle fibers during regeneration requires ADAM8, a member of a disintegr...

After initial patterning, muscle in the trunk and fins of teleosts grows extensively. Here, we describe muscle growth in zebrafish, with emphasis on the pectoral fin musculature. In the trunk, slow muscle fibers differentiate first. In contrast, slow muscle does not appear in the pectoral fin until the beginning of the juvenile period. Mosaic hyperplasia contributes to trunk muscle growth, and ...

Superior oblique muscle/trochlear nerve pairs from goldfish of various ages (1-5 years) have been examined light and electron microscopically. The muscle grows by enlargement (longitudinally and transversely) of individual fibers, and by addition of new ones at the rate of about 250/year. The nerve grows by enlargement of fibers, but few and perhaps no new axons are added. The somata enlarge, a...

The differential sensitivity of frog twitch and slow-tonic fibers to Ca(2+) and Sr(2+) suggests that these two fiber types express different troponin C (TnC) isoforms. To date, only one TnC isoform from anurans (resembling the mammalian fast-twitch isoform) has been isolated and characterized. In this study, we examined the possibility that anuran striated muscle contains more than one TnC isof...

EXTRAJUNCTIONAL ACETYLCHOLINE RECEPTORS ON MYOGENOUSLY DE-INNERVATED MUSCLE FIBERS Di ffuse extrajunct ional acetylcholine receptor (AChR) throughout the sarcolemma has been demon-strable in denervated (neurogenously de-innervated) skeletal muscle fibers pharmacologically by acetyl-choline sensitivity (1, 8) and morphologically by the binding of a-bungarotoxin (aBT) (5, 7, 9), in contrast to th...

The effect of animal maturity on fiber cross-sectional area, percentage of fiber types, activities of isocitrate dehydrogenase (ICDH) and lactate dehydrogenase (LDH), total and insoluble collagen and lipid concentration was investigated in the longis-simus thoracis (LT), semitendinosus (ST), and triceps brachii (TB) muscles. The analysis considered 2,642 muscle samples from bulls, steers, and c...

The cell specific detection of enzyme activation in response to the physiological contractile load within muscle-tendon-bone unit is essential for understanding of the mechanical forces transmission from muscle cells via tendon to the bone. The hypothesis that the physiological mechanical loading regulates activation of Akt1/PKBalpha at Thr308 and at Ser473 in muscle fibers within muscle-tendon...

BACKGROUND Patients with chronic heart failure (HF) frequently experience skeletal muscle weakness that limits physical function. The mechanisms underlying muscle weakness, however, have not been clearly defined. METHODS AND RESULTS This study examined the hypothesis that HF promotes a loss of myosin protein from single skeletal muscle fibers, which in turn reduces contractile performance. Te...

Patterns of activity of six dehydrogenase enzymes were studied histochemically in 42 free muscle grafts in the rat. Within hours, the surviving peripheral muscle fibers can be distinguished from the central ischemic muscle fibers. The surviving muscle fibers retain their characteristic pattern of staining throughout the post-transplantation period. The central ischemic muscle fibers stain abnor...

Alpha-synuclein (alpha-syn) is an important component of neuronal and glial inclusions in brains of patients with several neurodegenerative disorders. Sporadic inclusion-body myositis (s-IBM) is the most common progressive muscle disease of older patients. Its muscle phenotype shows several similarities with Alzheimer disease brain. A distinct feature of s-IBM pathology is specific vacuolar deg...