Article: Changes in membrane ionic conductances and excitability characteristics of rat skeletal muscle during aging

Membrane electrical properties, component ionic conductances and excitability characteristics of extensor digitorum longus muscle from 3-4, 16 and 29 months old rats were measured "in vitro". Fiber diameter, membrane resistance (Rm) and membrane capacitance, increased with aging, and the increase was significant at 29 months. The increase of Rm was mostly due to a decrease of chloride conductance (GC1), whereas potassium conductance (GK) increased only slightly, at 16 and 29 months. Due to the lowered GC1, the latency of action potential increased at both ages with a consequent prolongation of the duration of action potential. Nevertheless, a decrease in the firing capability was recorded in the aged fibers. Our results indicate, that during aging, the most affected parameter of skeletal muscle fibers is GC1, although changes of this passive conductance alone cannot entirely account for the changes in the excitability characteristics recorded.

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References

1.

Eddinger T, Cassens R, Moss R . Mechanical and histochemical characterization of skeletal muscles from senescent rats. Am J Physiol. 1986; 251(3 Pt 1):C421-30. DOI: 10.1152/ajpcell.1986.251.3.C421. View

2.

Grimby G, Saltin B . The ageing muscle. Clin Physiol. 1983; 3(3):209-18. DOI: 10.1111/j.1475-097x.1983.tb00704.x. View

3.

Larsson L, Grimby G, Karlsson J . Muscle strength and speed of movement in relation to age and muscle morphology. J Appl Physiol Respir Environ Exerc Physiol. 1979; 46(3):451-6. DOI: 10.1152/jappl.1979.46.3.451. View

4.

Camerino D, De Luca A, Mambrini M, Vrbova G . Membrane ionic conductances in normal and denervated skeletal muscle of the rat during development. Pflugers Arch. 1989; 413(5):568-70. DOI: 10.1007/BF00594192. View

5.

SMITH D, Weiler M . Acetylcholine metabolism and choline availability at the neuromuscular junction of mature adult and aged rats. J Physiol. 1987; 383:693-709. PMC: 1183097. DOI: 10.1113/jphysiol.1987.sp016436. View

6.

Camerino D, BRYANT S . Effects of denervation and colchicine treatment on the chloride conductance of rat skeletal muscle fibers. J Neurobiol. 1976; 7(3):221-8. DOI: 10.1002/neu.480070305. View

7.

Conte-Camerino D, Mambrini M, Deluca A, Tricarico D, BRYANT S, Tortorella V . Enantiomers of clofibric acid analogs have opposite actions on rat skeletal muscle chloride channels. Pflugers Arch. 1988; 413(1):105-7. DOI: 10.1007/BF00581238. View

8.

Adrian R, BRYANT S . On the repetitive discharge in myotonic muscle fibres. J Physiol. 1974; 240(2):505-15. PMC: 1331026. DOI: 10.1113/jphysiol.1974.sp010620. View

9.

HUTTER O, Warner A . The voltage dependence of the chloride conductance of frog muscle. J Physiol. 1972; 227(1):275-90. PMC: 1331275. DOI: 10.1113/jphysiol.1972.sp010032. View

10.

Dulhunty A, Franzini-Armstrong C . The passive electrical properties of frog skeletal muscle fibres at different sarcomere lengths. J Physiol. 1977; 266(3):687-711. PMC: 1283586. DOI: 10.1113/jphysiol.1977.sp011788. View

11.

HODGKIN A, Nakajima S . The effect of diameter on the electrical constants of frog skeletal muscle fibres. J Physiol. 1972; 221(1):105-20. PMC: 1331323. DOI: 10.1113/jphysiol.1972.sp009742. View

12.

Brooks S, Faulkner J . Contractile properties of skeletal muscles from young, adult and aged mice. J Physiol. 1988; 404:71-82. PMC: 1190815. DOI: 10.1113/jphysiol.1988.sp017279. View

Changes in Membrane Ionic Conductances and Excitability Characteristics of Rat Skeletal Muscle During Aging