Transverse and longitudinal sections through the sensory region of muscle spindles in the cat tenuissimus has shown no difference in the fine structure of sensory terminals lying on nuclear-bag or on nuclear-chain muscle fibers. Each terminal lies on a shallow trough of the intrafusal muscle fiber and is surrounded on its outer surface by basement membrane. A single terminal may encircle as muc...

The internal abdominal muscles are biaxially loaded in vivo, and therefore length-tension relations along and transverse to the directions of the muscle fibers are important in understanding their mechanical properties. We hypothesized that 1) internal oblique and transversus abdominis form an internal abdominal composite muscle with altered compliance than that of either muscle individually, a...

AIM Analysis of fiber type composition and fiber size of extensor digitorum longus (EDL) muscle in rats during 30 days of denervation. METHODS Fiber types were defined immunohistochemically using monoclonal antibodies specific for slow (type I) and fast fibers (type IIA, IIX, and IIB). Antibodies were applied on transverse sections of denervated extensor digitorum longus muscles 6, 12, and 30...

Striated muscle fibers appear with regularity in pituitary isografts transplanted beneath the kidney capsule. These differentiated striated muscle fibers consist of multinucleated cells resembling skeletal muscle fibers. They appear mainly in the pars distalis, though occasionally in the pars intermedia of the grafts. Although most glandular cells disappeared due to necrosis in the center of th...

After complete lumbar-ischiatic spinal cord injury (SCI) the lower motor neuron (LMN) denervated human muscle fibers lose completely the myofibrillar apparatus and the coil distribution of myonuclei that are relocated in groups (nuclear clumps) in the center of these “severely atrophic” muscle fibers. In our cohort of patients, the “severely atrophic” myofibers are frequent in muscle biopsies h...

Volumetric muscle injury (VML) causes an irrecoverable loss of muscle fibers, persistent strength deficits, and chronic disability. A crucial challenge to VML injury and possible regeneration is the removal of all of the in situ native elements necessary for skeletal muscle regeneration. Our first goal was to establish a reliable VML model in the mouse tibialis anterior (TA) muscle. In adult ma...

Striated muscle fibers and their spatial relationship to smooth muscle cells have been studied in the middle third of human esophagus. Biopsies were obtained from 3 patients during surgery. In both the circular and longitudinal layers, the muscle coat of this transition zone was composed of fascicles of uniform dimension (100-200 microns of diameter); some of these bundles were made up of stria...

The snake transversus abdominis muscle is an extremely simple segmentally repeating muscle containing 80 to 100 muscle fibers in a single-fiber-thick sheet. This muscle exhibits a striking pattern of muscle fiber types: twitch fibers alternate with tonic fibers and, among the twitch fibers, slower and faster contracting subtypes also alternate. Thus, in many regions of the muscle the pattern of...

Prompted by our recent observations that GLUT-1 is expressed in fetal muscles, but not in adult muscle fibers, we decided to investigate whether GLUT-1 expression could be reactivated. We studied different stimuli concerning their ability to induce GLUT-1 expression in mature human skeletal muscle fibers. Metabolic stress (obesity, non-insulin-dependent diabetes mellitus), contractile activity ...