Effects of local anesthetics and related drugs on endogenous glibenclamide-sensitive K+ channels in Xenopus oocytes.
Effects of local anesthetics and structurally related drugs on the glibenclamide-sensitive K+ currents evoked by Y-26763 (a K+ channel opener) were investigated in native Xenopus oocytes. The K+ current induced by Y-26763 (100 microM) was reversibly suppressed by all six local anesthetics tested in a concentration-dependent manner with the rank order of potencies (IC50 in microM): bupivacaine (67) > dibucaine (136) > tetracaine (845) > lidocaine (1710) = mepivacaine (1945) > procaine (3112). (+)-Propranolol and mexiletine also suppressed Y-26763-induced K+ currents with IC50 values of 115 microM and 789 microM, respectively. These results suggest that a suppressive action on glibenclamide-sensitive K+ channels is the common property of local anesthetics.
Yoneda
I
I
Department of Pharmacology, National Defense Medical College, Saitama, Japan.
Sakuta
H
H
Okamoto
K
K
Watanabe
Y
Y
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001578:Benzopyrans / Q000494:pharmacology; D002147:Calmodulin / Q000037:antagonists & inhibitors; D005260:Female; D005905:Glyburide / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D015221:Potassium Channels / Q000187:drug effects*; D014982:Xenopus laevis
D000779:Anesthetics, Local; D000959:Antihypertensive Agents; D001578:Benzopyrans; D002147:Calmodulin; D015221:Potassium Channels; C074338:Y 26763; D005905:Glyburide