Blockade of magnesium sulfate on transient outward K+ current and delayed rectifier K+ current in acutely isolated rat hippocampal neurons / 药学学报
Acta Pharmaceutica Sinica
;
(12): 510-515, 2002.
Article
in Chinese
| WPRIM
| ID: wpr-251111
ABSTRACT
<p><b>AIM</b>To study the effect of magnesium sulfate on transient outward K+ current (IA) and delayed rectifier K+ current (IK) in freshly dissociated hippocampal neurons of rats.</p><p><b>METHODS</b>The whole-cell patch clamp techniques were used.</p><p><b>RESULTS</b>Magnesium sulfate reversibly reduced the amplitudes of IA and IK in a concentration-dependent and voltage-dependent, but not frequency-dependent manner. Half-blocking concentration (IC50) on IA and IK were 6.30 mmol.L-1 and 7.60 mmol.L-1, respectively. Magnesium sulfate (6 mmol.L-1) affected the activation process of IA and IK. Before and after application of the drug, the half-activation voltages of IA were (7 +/- 6) mV and (-7 +/- 11) mV (n = 10, P < 0.01), and the half-activation voltages of IK were (20 +/- 6) mV and (28 +/- 4) mV (n = 10, P < 0.01), but the slope factors were not changed. In addition, magnesium sulfate (6 mmol.L-1) also affected the inactivation process of IA. Before and after application of the drug, the half-inactivation voltages of IA were (-65 +/- 5) mV and (-89 +/- 6) mV (n = 10, P < 0.01).</p><p><b>CONCLUSION</b>Magnesium sulfate inhibited IA and IK in freshly dissociated hippocampal neurons of rats, which might contribute to protect the central neuronal system (CNS) against damages induced by ischemia and oxygen deprivation.</p>
Full text:
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Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
Physiology
/
Potassium Channels
/
Cell Separation
/
Rats, Wistar
/
Patch-Clamp Techniques
/
Neuroprotective Agents
/
Cell Biology
/
Potassium Channels, Voltage-Gated
/
Delayed Rectifier Potassium Channels
Limits:
Animals
Language:
Chinese
Journal:
Acta Pharmaceutica Sinica
Year:
2002
Type:
Article
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