J Korean Neurosurg Soc.
1982 Mar;11(1):17-22.
Kinetic Analysis of Na-K-ATPase Activity of Rabbit Cerebral Cortex by DDVP
- Affiliations
-
- 1Department of Neurosurgery, Busan National University, Busan, Korea.
Abstract
- The kinetics of inhibition of Na-K-ATPase activity by o, 0-dimethyl o-(2,2-dichlorovinyl) phosphate(DDVP) was investigated with homogenerate of rabbit cerebral cortex. The results were summarized as the follows : 1. Inhibition of Na-K-ATPase activity by DDVP showed a dose-dependent manner with an estimated I5.0 of 3.5x10(-4) M. 2. Altered pH and activity curves for Na-K-ATPase activity demonstrated comparable inhibition by DDVP in buffered acidic, neutral and alkaline pH renges. 3. Kinetic studies of cationic-substrate activation of Na-K-ATPase showed noncompetitive with respect to substrate and K+ and a mixed type inhibition with respect to Na+. These results suggest that DDVP appeared to exert its effects on Na-K-ATPase activity by interfering with the formation of Na-dependent phosphoenzyme.