Quantitative Measurement of Membrane Na+-K+ ATPase Activity using Thallium-201: Comparison with Rubidium-86.
- Author:
Jaetae LEE
;
Jae Tae LEE
;
Sang Kyun SOHN
;
In Kyu LEE
- Publication Type:In Vitro ; Original Article
- Keywords:
Na+-K+ ATPase activity;
Thallium-201;
Rubidium-86
- MeSH:
Adenosine Triphosphatases*;
Animals;
Aorta;
Cardiac Glycosides;
Glucose;
Humans;
Insulin;
Membranes*;
Myocytes, Smooth Muscle;
Myristic Acid;
Ouabain;
Potassium;
Rats;
Umbilical Arteries
- From:Korean Journal of Nuclear Medicine
1998;32(2):121-128
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: Na+-K+ ATPase Activity has beem estimated by the degree of inhibition of cation transport by cardiac glycosides (ouabain) using Rb-86 as a substrate. The biological characterist-Isc of T1-201 is known to be simiIar to those of potassium as a transport substrate in the presence of glucose, insulin or phobol myristate acetate (PMA). The purpose of this study was to measure ouabain sensitive Na+-K+ ATPase activity using T1-201 and compare with that using Rb-86. MATERIALS AND METHODS: Smooth muscle cells isolated from rat aorta or human placental umbilical artery were cultured, and used to measure cellular Na+-K+ ATPase activity. Na+-K+ ATPase activity was measured as a percentage decrease in cellular uptake of T1-201 or Rb-86 by ouabain under the presence of glucose, insulin or PMA in media. RESULTS: Na+-K+ ATPase ase activity measured with T1-201, as a transport substrate, was not different from those measured with Rb-86 in rat or human smooth muscle cell preparation. Incubation with high concentration glucose resulted in about 30% decrease in enzyme activity. In contrast, insulin or PMA resulted in 50-70% or 28% increases from baseline activity, respectively. CONCLUSION: These results suggests that T1-201 could replace Rb-86 in measurement of ouabain sensititive Na+-K+ ATPase activity in vitro. High level of glucose concentration decreased cellular Na+-K+ ATPase activity, but insulin or PMA increased it.
