Analysis of the inhibitory effect of gypenoside on Na(+), K (+)-ATPase in rats' heart and brain and its kinetics.
- Author:
Xiao-yan HAN
1
;
Hong-bo WEI
;
Fu-cheng ZHANG
Author Information
- Publication Type:Journal Article
- MeSH: Adenosine Triphosphate; pharmacology; Animals; Brain; enzymology; Enzyme Inhibitors; pharmacology; Gynostemma; Kinetics; Male; Myocardium; enzymology; Plant Extracts; pharmacology; Rats; Rats, Wistar; Sodium-Potassium-Exchanging ATPase; antagonists & inhibitors
- From: Chinese journal of integrative medicine 2007;13(2):128-131
- CountryChina
- Language:English
-
Abstract:
OBJECTIVETo study the effects of gypenoside (Gyp) on the activity of microsomal Na(+), K(+)-ATPase in rat's heart and brain in vitro.
METHODSThe microsomal Na(+), K(+)-ATPase was prepared from rat's heart and brain by differential centrifugation. The activity of microsomal Na(+), K(+)-ATPase was assayed by colorimetric technique. Enzyme kinetic analysis method was used to analyze the effect of Gyp on the microsomal Na(+), K(+)-ATPase of rats.
RESULTSGyp reversibly inhibited the brain and heart's microsomal Na(+), K(+)-ATPase in a concentration-dependent manner, and showed a more potent effect on enzyme in the brain. The IC(50) of Gyp for the heart and brain were 58.79+/-8.05 mg/L and 52.07+/-6.25 mg/L, respectively. The inhibition was enhanced by lowering the Na(+), or K(+) concentrations or increasing the ATP concentration. Enzyme kinetic studies indicated that the inhibitory effect of Gyp on the enzyme is like that of competitive antagonist of Na(+), the counter-competitive inhibitor for the substrate ATP, and the mixed-type inhibitor for K(+).
CONCLUSIONGyp displays its cardiotonic and central inhibitory effects by way of inhibiting heart and brain's microsomal Na(+), K(+)-ATPase activities in rats.
