Сторінка 1 від 58 результати
OBJECTIVE
Fatigue has been shown to cause intrinsic alterations in sarcoplasmic reticulum (SR) Ca2+ release.
METHODS
In this investigation, frog semitendinosus muscles were stimulated to fatigue, in vitro (80 Hz, 100 ms, 1 train s-1, 5 min). Immediately after stimulation, single fibres were removed
The effects of 17beta-estradiol (10(-5) M), an active estrogen, on the tension and fatigue responses of single fiber or fiber bundle prepared from frog skeletal muscle were investigated. The administration of 17beta-estradiol caused a transient potentiation of tetanus tension by field stimulation at
The effect of increasing age on contractile performance and catecholamine receptor activity was investigated in a distal, predominantly fast twitch oxidative glycolytic (FOG) muscle from the plantar surface of the rat hindfoot. The ability of the flexor digitorum brevis (FDB), isolated from
We have examined the influence of electrical stimulation on caffeine-induced tension generation during contracture testing used to diagnose malignant hyperthermia. The cumulative contracture response to caffeine was compared in pairs of morphologically comparable muscle bundles obtained from the
The purpose of this investigation was to examine the Ca2+ and caffeine sensitivities of skinned skeletal muscle fibers after fatigue. Single frog semitendinosus fibers were chemically skinned in either a rested state or after tetanic contractions (80 Hz, 100 ms) evoked at 2 s-1 for 5 min. This
In fatigued muscles the T-system is swollen; thus the action potential may fail to travel along the T-system or the T-tubule terminal cisternae signal may fail to bring about TC Ca2+ release. This would lead to a decrease in the number of myofibrils activated and in force development, but if fatigue
1. Single fibres isolated from the anterior tibialis muscle of Rana temporaria (temperature, 2-5 degrees C; sarcomere length, 2.10 microns) were fatigued using two separate protocols that led to different degrees of depression of tetanic force. Under control conditions the fibre was stimulated to
1. The purpose of this investigation was to determine if alterations in extracellular calcium (Ca2+) influx by the dihydropyridine derivatives Bay K 8644 and nifedipine affected skeletal muscle fatigue. 2. Tetanic contractions (80 Hz, 100 msec) of frog sartorius muscles were evoked every sec for 3
We studied whether hydrogen peroxide (H(2)O(2)) at =10 microM activates the ryanodine receptor and decreases releasable Ca(2+) content in the sarcoplasmic reticulum after fatigue. Exposure of rabbit or frog skeletal muscle ryanodine receptors to 10 microM H(2)O(2) enhanced channel activity in
In muscle phosphorylase deficiency (McArdle's disease) there is an abnormally rapid fatigue during strenuous exercise. Increasing substrate availability to working muscle can improve exercise tolerance but the effect on muscle energy metabolism has not been studied. Using phosphorus-31 nuclear
At the first International Congress of Physiologists in Basel, Switzerland, the Italian physiologist Angelo Mosso (1846-1910) discussed his findings on muscular fatigue while demonstrating the functioning of an ergograph (work recorder). One hundred sixteen years later, Mosso's career, scientific
To assess the impairment of muscle membrane excitation, excitation-contraction (E-C) coupling, and contractility during muscle fatigue, we monitored the contracture responses of resting and fatigued muscles on exposure to high potassium and caffeine. On exposure to 140 mmol/L potassium, mouse
The properties of caffeine contracture and potassium contracture in fatigued single fibers were examined in detail using frog semitendinosus muscle, Rana japonica. Fatigue was caused by repetitive stimulation at 2 Hz. The dose-response curve of caffeine contracture in the fatigued fibers was shifted
Episodic ataxia type 1 (EA1) is a human dominant neurological syndrome characterized by continuous myokymia, episodic attacks of ataxic gait and spastic contractions of skeletal muscles that can be triggered by emotional stress and fatigue. This rare disease is caused by missense mutations in the