Involvement of Na+, K+-ATPase in hypoxia-induced increase of cytosolic Ca2+ in rat cortical neurons
- Author:
Shi LI
1
Author Information
1. Department of Pharmacology
- Publication Type:Journal Article
- Keywords:
Anoxia;
K+-ATPase;
Na+;
Neurons
- From:
Academic Journal of Second Military Medical University
2010;28(1):44-47
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the effect of Na+, K+ -ATPase on the increase of cytosolic Ca2+ level induced by hypoxia in rat cortical neurons. Methods: Using confocal laser scanning microscope and video based motion edge detection system, we measured the intracellular Ca2+ concentration ([Ca2+]i) and Na+ concentration ([Na+]i) in cortical neurons exposed to hypoxia for different time periods and at presence of different concentrations of dihydroouabain (DHO, an inhibitor of Na+, K+-ATPase). We also observed the effect of Na+, K+-ATPase on the increase of cytosolic Ca2+ level induced by hypoxia in rat cortical neurons. Results: DHO (10-9-10-3 mol/L) dose-dependently and hypoxia(4-20 min) time-dependently increased the levels of [Ca2+]i and [Na+]i in cultured cortical neurons. [Ca2+]i and [Na+]i increased significantly 4 min after cortical neurons were exposed to hypoxia, and addition of DHO (10-3 mol/L) further increased their concentrations. While 15 min after hypoxia exposure, different concentrations of DHO did not further increase [Ca2]i and [Na+]i. We also found that hypoxia exposure did not enhance DHO pretreatment-induced [Ca2+]i increase. Conclusion: Inhibition of Na+, K+ -ATPase activity is one of the mechanisms responsible for hypoxia-induced elevation of [Ca2+]i in cortical neurons.
