Beta-adrenergic modulation of the Na+-K+ pump in frog skeletal muscles.
Adrenaline markedly increased the ouabain-sensitive 22Na+-efflux by stimulating the Na+-K+ pump in frog skeletal muscle. The facilitatory effects of adrenaline had the following properties. The effects of adrenaline on the ouabain-sensitive Na+-efflux were observed at concentrations greater than 0.1 microM and the magnitude increased with concentration up to 10 microM. At a concentration of 30 microM, adrenaline markedly augmented the ouabain-sensitive Na+-efflux, but other biogenic amines were less effective (noradrenaline and dopamine) or ineffective (histamine and serotonin). The increase of Na+-efflux induced by 1 microM adrenaline was blocked by 3 microM propranolol, but not by 3 microM phenoxybenzamine. The properties of the facilitatory action of adrenaline on the ouabain-sensitive Na+-efflux suggest that beta-adrenoceptors have an important role in modulating the Na+-K+ pump activity in the skeletal muscle membrane. The protein complex localized in excitable membranes, namely the Na+-K+ ATPase-beta-adrenoceptor complex, may be the functional unit which operates the membrane machinery driving the Na+-K+ pump.
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Kaibara
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Akasu
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Tokimasa
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Koketsu
D000818:Animals; D004837:Epinephrine / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D009132:Muscles / Q000378:metabolism*; D009994:Osmolar Concentration; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D013565:Sympatholytics / Q000494:pharmacology
D007473:Ion Channels; D011943:Receptors, Adrenergic, beta; D013565:Sympatholytics; D010042:Ouabain; D012964:Sodium; D011188:Potassium; D004837:Epinephrine