[Smooth muscle and cardiac glycosides (author's transl)].
Actions of cardiac glycosides (C.G.) on smooth muscles are reviewed. 1. C.G. inhibit the Na-K ATPase of smooth muscle membrane, though the degree and mode of the inhibition vary among the types of smooth muscles. 2. The uptake of C.G. by smooth muscles has been reported to be influenced by K+, Na, ATP, and temperature. The difference between the uptake and its effect can be observed. 3. Intracellular K concentration decreased and intracellular Na concentration increased by the treatment with C.G. 4. They depolarized the membrane; the action being affected by extracellular ion concentration. An increase in spike discharges is observed. 5. C.G. potentiate or inhibit the concentrations of smooth muscles, depending on the types of smooth muscles and the causes of the contraction. C.G. can also cause transient contraction of smooth muscle. 6. C.G. influence the Ca content and Ca movements of smooth muscles. 7. C.G. cause the release of noradrenaline, acetylcholine, or prostaglandins. These substances can affect the contractile responses of smooth muscles.
D000818:Animals; D002301:Cardiac Glycosides / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D010042:Ouabain / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
D002301:Cardiac Glycosides; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium