Inhibition of sarcolemma ATPases by some membrane-stabilizing drugs.
Rat sarcolemma preparations were incubated with some membranes stabilizers to study their effects on the (Na+,K+)- and Ca2+-ATPase activity. The drugs inhibited the enzymes with the same order of potency as in the earlier observed muscle contractures: chlorpromazine greater than dibucaine greater than propranolol greater than tetracaine greater than procaine (range 0.1-3.6 mM) (Røed & Brodal 1979). The contracture inducing effect of the stabilizers is suggested to be caused by a membrane depolarization due to the (Na+,K+)-ATPase inhibition. Ouabain inhibited the (Na+,K+)-ATPase activity in purified plasma membrane, but did not inherit the sarcolemma located ATPases or induce any contracture.
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors*; D002746:Chlorpromazine / Q000494:pharmacology; D003992:Dibucaine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D010042:Ouabain / Q000494:pharmacology; D011343:Procaine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D012508:Sarcolemma / Q000201:enzymology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013748:Tetracaine / Q000494:pharmacology
D013748:Tetracaine; D011343:Procaine; D010042:Ouabain; D011433:Propranolol; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; D003992:Dibucaine; D002746:Chlorpromazine