Inhibition of rat brain Na+-K+-ATPase by triterpene glycosides from holothurians.
The effect of triterpene glycosides from holothurians on Na+-K+-ATPase of rat brain was investigated. The marine glycosides are irreversible inhibitors of the enzyme with an average I50 value of 10(-4) M. ATP had a low protective effect against inhibition. The inhibitory effect was increased by preincubation with MgCl2. There was alteration of the activation curve of Na+-K+-ATPase by NaCl and KCl in the presence of glycosides. Triterpene glycosides inhibited the K+-phosphatase activity, but to a smaller degree than the ATPase activity. Na+-K+-ATPase of pig kidney was less sensitive to the marine triterpene glycosides than the brain enzyme. The marine glycosides did not alter the specific binding of [3H]-ouabain to the Na+-K+-ATPase.
Gorshkova
I A
IA
Pacific Institute of Bioorganic Chemistry, Far East Branch of U.S.S.R. Academy of Sciences, Vladivostok.
Gorshkov
B A
BA
Stonik
V A
VA
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000201:enzymology*; D006027:Glycosides / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D012616:Sea Cucumbers; D012964:Sodium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000494:pharmacology*
D006027:Glycosides; D014315:Triterpenes; D015636:Magnesium Chloride; D010042:Ouabain; D000255:Adenosine Triphosphate; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D008274:Magnesium; D011188:Potassium