Comparison of the inhibitory effect of ouabain and dihydroouabain on the Na(+)-K+ ATPase from frog skin.
1. The effects of ouabain and dihydroouabain (DHO) on Na(+)-K+ ATPase from frog skin were investigated. 2. Ouabain seemed to be a more effective inhibitor, reaching near maximum inhibition at 10(-5) M while DHO reached near maximum at 10(-3) M. 3. Both inhibitors acted within the first few minutes, but ouabain inhibited more strongly over virtually the whole 2 hr considered. 4. Pre-incubation of the enzyme with ATP or Na+ reduced the level of inhibition due to subsequent ouabain or DHO, but preincubation with K+ did not.
Nichols
J R
JR
Department of Biology, Abilene Christian University, TX 79699-8199.
Maldonado
H S
HS
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D010042:Ouabain / Q000031:analogs & derivatives* / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D011894:Rana pipiens; D012867:Skin / Q000201:enzymology*; D012964:Sodium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
C000977:dihydroouabain; D010042:Ouabain; D000255:Adenosine Triphosphate; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium