A method has been developed permitting measurement of membrane impedance and current, as a function of transmembrane potential, at small, electrically isolated regions of the muscle cell surface without microelectrode impalement. The frequency dependence of the muscle cell membrane capacity found earlier by other methods has been confirmed. The average capacity is 3.5 /zf/cm ~ with a phase angl...

A method has been developed permitting measurement of membrane impedance and current, as a function of transmembrane potential, at small, electrically isolated regions of the muscle cell surface without microelectrode impalement. The frequency dependence of the muscle cell membrane capacity found earlier by other methods has been confirmed. The average capacity is 3.5 /zf/cm ~ with a phase angl...

The principal aim of this work was to better understand how regenerating muscle fibers become innervated in adult animals. To induce muscle regeneration, individual identified muscle fibers in a mouse were damaged with a laser focused through a microscope. The muscle fiber that degenerated and the muscle fiber that was formed in its place were followed by viewing the same site repeatedly over a...

PURPOSE It is now established that unaccustomed eccentric exercise leads to muscle fiber damage and to delayed-onset muscle soreness (DOMS) in the days after exercise. However, a second bout of eccentric exercise, a week after the first, produces much less damage and soreness. The purpose of this study was to provide evidence from muscle mechanical properties of a proposed mechanism for this tr...

objective(s): previous studies showed that skeletal muscle microcirculation was reduced in chronic heart failure. the aim of this study was to investigate the effects of endurance training on capillary and arteriolar density of fast and slow twitch muscles in rats with chronic heart failure. materials and methods: four weeks after surgeries (left anterior descending (lad) artery occlusion), chr...

Introduction: Ursolic Acid (UA) is a lipophilic triterpenoid compound, found in large amounts in apple peel. Anabolic effects of UA on the skeletal muscle and the role of this tissue as a key regulator of systematic aging aroused this question in mind whether UA might amend skeletal muscle performances such as myoglobin expression and also whether it switches skeletal muscle fibers from glyc...

Ontogenetic changes in the organization and volume fraction of collagenous connective tissues were examined in the mantle of Sepioteuthis lessoniana, the oval squid. Outer tunic fiber angle (the angle of a tunic collagen fiber relative to the long axis of the squid) decreased from 33.5 degrees in newly hatched animals to 17.7 degrees in the largest animals studied. The arrangement of intramuscu...

BACKGROUND The loss of skeletal muscle mass with aging has been attributed to a decline in muscle fiber number and muscle fiber size. OBJECTIVE To define to what extent differences in leg muscle cross-sectional area (CSA) between young and elderly men are attributed to differences in muscle fiber size. METHODS Quadriceps muscle CSA and type I and type II muscle fiber size were measured in h...

Proton density (PD) and diffusion tensor imaging (DTI) are techniques that enable the acquisition of data from living subjects can be used in fine-tuning subject-specific models’ architectural parameters. The aim this study was to determine vivo 3D parameters (volume, pennation angle, fiber length physiological cross-sectional area) gastrocnemius medialis, lateralis, soleus tibialis anterior mu...

The number of muscle fibers in the vocal organ of the adult male African clawed frog, Xenopus laevis, exceeds that of adult females. This sex difference is the result of rapid fiber addition in males between the end of metamorphosis, post-metamorphic stage 0 (PM0) and PM2. At PM0, male and female frogs have similar numbers of laryngeal muscle fibers. Males then add more muscle fibers than femal...