Properties Of Skeletal Muscle Fibers Research Articles

Electrical properties of skeletal muscle fibres of the flour moth larva Ephestia kuehniella

The electrical properties of the ventral longitudinal muscle fibres in the flour moth larva Ephestia kuehniella were investigated at rest and during electrical activity. The membrane resting potential was only partially dependent on the K-concentration gradient across the muscle membrane. The electrical constants λ, τ, R m , R i , and C m were determined according to the equations for ‘short cables’ (Table 1). Current-voltage relationships of the muscle membrane were measured: they revealed anomalous as well as delayed rectification of the membrane. Stimulation of the muscle fibres with intracellular current pulses elicited graded action potentials in most fibres; in some fibres ‘all-or-none’ action potentials were generated. In contrast to graded action potentials these ‘all-or-none’ action potentials were propagated without decrement along the muscle fibre. Indirect stimulation of the muscle fibres resulted in large excitatory junction potentials which generally gave rise to action potentials.

Mechanism of disturbance of the functional properties of striated muscle fibers in postdiphtheritic polyneuritis and experimental allergic encephalomyelitis

The development of the paralytic syndrome in postdiphtheritic polyneuritis was characterized by a sharp decrease in polarization of the muscle fibers, the accumulation of sodium and potassium ions and noradrenalin in them, and by a deficiency of adrenalin. In experimental allergic encephalomyelitis the polarization of the skeletal muscle fibers was not significantly changed, despite the marked increase in the concentrations of sodium, potassium, adrenalin, and noradrenalin in the muscle, tissue. It is concluded that changes in the functional properties of skeletal muscle fibers in postdiphtheritic polyneuritis, unlike those in experimental allergic encephalomyelitis, are evidently due to a disturbance of regulatory nervous influences on the processes of electrogenesis in the muscle fibers.

Histochemical, biochemical, and contractile properties of red, white, and intermediate fibers.

Histochemical, biochemical, and contractile properties of red, white, and intermediate fibers.

A histochemical-physiological correlation of frog skeletal muscle fibers.

A histochemical-physiological correlation of frog skeletal muscle fibers.