Category: Parkinson's Disease (Other)
Objective: This study aimed to investigate the direct effect of dopamine on Na,K-ATPase activity in rat hippocampal membranes and to determine whether this effect depends on dopamine concentration and oxidative conditions.
Background: Dopamine is an important neurotransmitter that regulates neuronal signaling and synaptic activity in the brain. Besides classical receptor-mediated mechanisms, dopamine may also directly influence membrane proteins such as Na,K-ATPase, an enzyme that plays a key role in maintaining ionic gradients and neuronal excitability.
Method: Na,K-ATPase activity was determined in hippocampal membrane preparations by measuring MgATP-dependent ATP hydrolysis. The enzyme activity was analyzed at different dopamine concentrations. In addition, the influence of ouabain and cytochrome c was examined in order to evaluate possible interactions between dopamine, cardiotonic steroids, and oxidative processes.
Results: The results demonstrate that dopamine has a biphasic effect on Na,K-ATPase activity. Low concentrations of dopamine stimulated the enzyme, whereas higher concentrations produced inhibition. Kinetic analysis showed that dopamine modified enzyme activity without changing the relative contribution of the α₁ and α₂/α₃ subunits. Simultaneous exposure to dopamine and low concentrations of ouabain resulted in a pronounced activation of the enzyme system. In the presence of cytochrome c, the effect of dopamine was altered, suggesting that oxidation of dopamine contributes to the modulation of Na,K-ATPase activity.
Conclusion: These findings indicate that dopamine can directly modulate Na,K-ATPase activity through concentration-dependent mechanisms. The results suggest that dopamine may influence neuronal ion homeostasis not only through receptor signaling but also through direct interactions with membrane systems, particularly under conditions associated with oxidative stress.
To cite this abstract in AMA style:
G. Chkadua, E. Nozadze, L. Shioshvili, L. Tsakadze, S. Dzneladze, N. Arutinova, M. Leladze, M. Javakhishvili. Dopamine and Na,K-ATPase: Mechanisms of Direct Enzyme Modulation in the Hippocampus [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/dopamine-and-nak-atpase-mechanisms-of-direct-enzyme-modulation-in-the-hippocampus/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/dopamine-and-nak-atpase-mechanisms-of-direct-enzyme-modulation-in-the-hippocampus/