The effect of niflumic acid and blocker of calcium channel on the desensitization of gamma aminobutyric acid-activated current / 中国应用生理学杂志
Chinese Journal of Applied Physiology
; (6): 128-132, 2013.
Article
ي Zh
| WPRIM
| ID: wpr-358660
المكتبة المسؤولة:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To explore the modulatory effect of niflumic acid and blocker of calcium channel on the desensitization of gamma aminobutyric acid (GABA)-activated currents in dorsal root ganglion(DRG) neurons from rat.</p><p><b>METHODS</b>The whole-cell patch-clamp technique was used to observe the modulatory effect of niflumic acid and blocker of calcium channel on the desensitization of GABA-activated currents in neurons freshly dissociated from rat DRG neurons.</p><p><b>RESULTS</b>Application of GABA (0.1-1 000 micromol/L) could induce concentration-dependent inward currents in some cells (212/223, 95.11%). GABA-(100 micromol/L) activated currents was (1.32 +/- 0.74) nA (n = 84). However, pre-application of niflumic acid (1-100 micromol/L) and nitrendipine (specific blocker of L-calcium channel)(0.1-30 micromol/L) could inhibit the GABA-activated inward current which was identified to be GABAA receptor-mediated current. The inhibitory effects of niflumic acid and nitrendipine were concentration-dependent. The suppression rate of 10 micromol/L niflumic acid and nitrendipine to GABA-activated currents were (31.60% +/- 4.87%) (n = 19) and (43.60% < or = 5.10%) (n = 5), respectively. The desensitization of GABA-activated currents had double exponential characteristic. Tau value was (14.68 +/- 5.11) s (n = 6) and (175.8 +/- 42.67) s (n = 6, r = 0.9647), respectively. Pre-application of niflumic acid (100 micromol/L) and nickel chloride (nonspecific blocker of L-calcium channel) (100 micromol/L) altered tau value of the desensitization of GABA-activated currents, tau value reduced for (4.64 +/- 2.21) s (n = 3), (43.70 +/- 14.34) s ( n = 3, r = 0.9548) and (4.64 +/- 2.21) s (n = 3), (43.70 +/- 14.34) s (n = 3, r = 0.9721).</p><p><b>CONCLUSION</b>Pre-application of niflumic acid exerts a more strong inhibitory effect on the peak value of GABA-activated current, which possibly is through blocking the calcium-activated chloride ion channel to accelerate the desensitization of GABA-activated currents.</p>
النص الكامل:
1
الفهرس:
WPRIM
الموضوع الرئيسي:
Pharmacology
/
Physiology
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Calcium Channel Blockers
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Nitrendipine
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Niflumic Acid
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Rats, Sprague-Dawley
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Patch-Clamp Techniques
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Calcium Channels, L-Type
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Gamma-Aminobutyric Acid
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Ganglia, Spinal
نوع الدراسة:
Prognostic_studies
المحددات:
Animals
اللغة:
Zh
مجلة:
Chinese Journal of Applied Physiology
السنة:
2013
نوع:
Article