Effects of sodium metabisulfite on potassium currents in acutely isolated rat hippocampal CA1 neurons / 中国应用生理学杂志
Chinese Journal of Applied Physiology
;
(6): 241-246, 2005.
Article
in Chinese
| WPRIM
| ID: wpr-287046
ABSTRACT
<p><b>AIM</b>To investigate the effects of sodium metabisulfite (SMB), sulfur dioxide (SO2) and its derivatives in vivo, sodium bisulfite and sulfite on K+ channels of the central neurons and its mechanisms.</p><p><b>METHODS</b>By using whole-cell patch-clamp technique, the effects of SMB on transient outward K+ (I(A)) and delayed rectifier K+ currents(IK) were observed.</p><p><b>RESULTS</b>(1) SMB can increase the amplitudes of I(A) and I(K) in a dose-dependent and voltage-dependent manner. Their half-increase doses were 15.8 micromol/L and 11.5 micromol/L respectively. (2) SMB (10 micromol/L) significantly shifted the activation curves of I(A) and I(K) to more positive potentials. Before and after application of 10 micromol/L SMB, the half-activation voltages of I(A) and I(K) were (- 12.6 +/- 1.6) mV and (- 7.0 +/- 1.3) mV, (10.8 +/- 0.9) mV and (21.6 +/- 0.7) mV (P < 0.01, n = 8), respectively, but the slope factors were not changed. (3) The inactivation curve of I(A) was shifted to positive potentials, the half-inactivation voltage of I(A) were (- 97.0 +/- 1.1) mV and (- 84.4 +/- 3.3) mV (P < 0.01, n = 8) before and after application of SMB (10 micromol/L), without changing the slope factors. (4) SOD, CAT and GPx could partly inhibit the incremental effect of SMB on I(A) and I(K).</p><p><b>CONCLUSION</b>SMB, SO2 and its derivatives in vivo, sodium bisulfite and sulfite have the damage effects on the central nervous system, and they can cause extracellular K+ increase and induce the disturbance of the central neuronal functions. Its mechanism may involve oxidation damage in the rat hippocampal CA1 neurons, caused by sulfur- and oxygen-centered free radicals formed in the process of sulfite or bisulfite oxidation.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
Physiology
/
Sulfites
/
Sulfur Dioxide
/
Potassium Channels
/
Rats, Wistar
/
Patch-Clamp Techniques
/
Cell Biology
/
Hippocampus
/
Membrane Potentials
Limits:
Animals
Language:
Chinese
Journal:
Chinese Journal of Applied Physiology
Year:
2005
Type:
Article
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