Regulation of the sodium‐potassium pump in cultured rat skeletal myotubes by intracellular sodium ions

Journal of Cellular Physiology - Tập 140 Số 1 - Trang 131-137 - 1989
Chaya Brodie1, Sanford R. Sampson1
1Health Sciences Research Center, Department of Life Sciences, Bar‐llan University Ramat‐Can, Israel 52900

Tóm tắt

AbstractThe properties of the Na‐K pump and some of the factors controlling its amount and function were studied in rat myotubes in culture. The number of Na‐K pump sites was quantified by measuring the amount of [3H]ouabain bound to whole‐cell preparations. Activity of the pump was determined by measurement of oua‐bain‐sensitive 86Rb‐uptake and component of membrane potential. Chronic treatment of myotubes with tetrodotoxin (TTX), which lowers [Na]i, decreased the number of Na‐K pumps, the ouabain‐sensitive 86Rb uptake, and the size of the electrogenic pump component of Em. In contrast, chronic treatment with either ouabain or veratridine, which increases [Na+]i, resulted in an elevated level of Na‐K pump sites. This effect was blocked by inhibitors of protein synthesis. Neither rates of degradation nor affinity of pump sites in cells treated with TTX, veratridine, or ouabain differred from those in control cells. The number and activity of Na‐K pump sites were unaffected by chronic elevation in [Ca]i or chronic depolarization. We conclude that alterations in the level in intracellular Na ions play the major role in regulation of Na‐K pump synthesis in cultured mammalian skeletal muscle.

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Tài liệu tham khảo

10.1113/jphysiol.1975.sp010858

10.2170/jjphysiol.33.279

10.1113/jphysiol.1972.sp009904

10.1007/BF00583913

10.1113/jphysiol.1972.sp009960

10.1016/0003-2697(76)90527-3

10.1113/jphysiol.1974.sp010521

10.1113/jphysiol.1976.sp011301

10.1016/0006-8993(85)90674-2

10.1002/jcp.1041300204

Brodie C.Brody M. andSampson S. R.(1989) Characterization of the relation between sodium channels and electrical activity in cultured rat skeletal myotubes: Regulatory. aspects.Brain Res. in press.

10.1016/0006-8993(85)90885-6

10.1016/0006-8993(85)90896-0

10.1016/0736-5748(86)90050-X

10.1016/0006-8993(87)91632-5

Brodie C., 1987, Effects of chronic ethanol treatment on membrane potential, its electrogenic pump component and Na‐K pump activity of cultured rat skeletal myotubes, J. Pharma‐col. Exp. Ther., 242, 1104

10.1210/endo-123-2-891

Clausen T., 1982, Effects of age, potassium depletion and denervation on specific displaceable [3H]‐ouabain binding in muscles of normal and potassium‐depleted rats, J. Physiol. London, 34, 123

10.1146/annurev.ph.44.030182.002133

10.1523/JNEUROSCI.05-09-02559.1985

Hermsmeyer K., 1983, Sodium pump hyperpolarization‐relaxation in rat caudal artery, Fed. Proc., 42, 246

10.1152/ajpcell.1984.246.5.C551

10.1161/01.RES.55.1.39

10.1007/BF00583377

10.1007/BF00585350

10.1002/jez.1401660310

10.1152/ajpcell.1981.241.5.C173

10.1038/264368a0

10.1016/0012-1606(71)90017-0

10.1073/pnas.81.1.262

Sherman S. J., 1983, Tetrodotoxin‐sensitive sodium channels in rat muscle cells developing in vitro, J. Biol. Chem., 25, 2488, 10.1016/S0021-9258(18)32952-1

10.1152/physrev.1972.52.3.563

10.1002/jcp.1041090203

Vigne P., 1982, Ontogeny of the Na‐K ATPase during chick skeletal myogenesis, J. Biol. Chem., 257, 5380, 10.1016/S0021-9258(19)83787-0

Wolitzky B. A., 1986, Regulation of the (Na+ K+)‐ATPase in cultured chick skeletal muscle. Regulation of expression by the demand for ion transport, J. Biol. Chem., 261, 9990, 10.1016/S0021-9258(18)67613-6

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Journal of Cellular Physiology

Tập 140 Số 1

131-137

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