Effects of Cl- channel blockers on the cardiac ATP-sensitive K+ channel
The Korean Journal of Physiology and Pharmacology
; : 305-313, 1999.
Article
de En
| WPRIM
| ID: wpr-728244
Bibliothèque responsable:
WPRO
ABSTRACT
To explore whether Cl- channel blockers interact with the ATP-sensitive K+ (KATP) channel, I have examined the effect of two common Cl- channel blockers on the KATP channel activity in isolated rat ventricular myocytes using patch clamp techniques. In inside-out patches, 4,4'-diisothio-cyanatostilbene-2,2'-disulfonic acid (DIDS) and niflumic acid applied to bath solution inhibited the KATP channel activity in a concentration-dependent manner with IC50 of 0.24 and 927 muM, respectively. The inhibitory action of DIDS was irreversible whereas that of niflumic acid was reversible. Furthermore, DIDS-induced block was not recovered despite exposure to ATP (1 mM). In cell-attached and inside-out patches, DIDS blocked the pinacidil- or 2,4-dinitrophenol (DNP)-induced KATP channel openings. In contrast, niflumic acid did not block the pinacidil-induced KATP channel openings in inside-out patches, but inhibited it in cell-attached patches. DIDS and niflumic acid produced additional block in the presence of ATP and did not affect current-voltage relationship and channel kinetics. All these results indicate that DIDS among Cl- channel blockers specifically blocks the cardiac KATP channel.
Mots clés
Texte intégral:
1
Indice:
WPRIM
Sujet Principal:
Bains
/
Cinétique
/
Adénosine triphosphate
/
Acide niflumique
/
Acide 4,4'-diisothiocyano-stilbène-2,2'-disulfonique
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Techniques de patch-clamp
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2,4-Dinitro-phénol
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Concentration inhibitrice 50
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Cellules musculaires
Type d'étude:
Diagnostic_studies
Limites du sujet:
Animals
langue:
En
Texte intégral:
The Korean Journal of Physiology and Pharmacology
Année:
1999
Type:
Article