Different glibenclamide-sensitivity of ATP-sensitive K+ currents using different patch-clamp recording methods.
Different glibenclamide-sensitivity of ATP-sensitive K+ currents using different patch-clamp recording methods.
复制标题
使用不同膜片钳记录方法的 ATP 敏感 K 电流的不同格列本脲敏感性。
DOI：
10.1016/j.ejphar.2005.12.011
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发表时间：
2006
影响因子：
5
通讯作者：
Y. Ito
中科院分区：
文献类型：
--
作者：
N. Teramoto;T. Tomoda;T. Yunoki;Y. Ito
Electorophysiological and pharmacological properties of the levcromakalim-induced inward ATP-sensitive K+currents (KATPcurrents) in pig proximal urethra were investigated by use of two different whole-cell patch-clamp techniques, namely conventional whole-cell and nystatin-perforated patch recordings. In conventional whole-cell configuration, the levcromakalim (100 μM)-induced KATPcurrent decayed by about 30% in 8 min at a holding potential of −50 mV. In contrast, with the nystatin-perforated patch, 96% of the levcromakalim-induced KATPcurrent still remained even after 8 min application of levcromakalim. The peak amplitude of the levcromakalim-induced inward KATPcurrents in nystatin-perforated patch was approximately half of those observed in conventional whole-cell configuration. When cytosolic extract of pig urethra was included in the pipette solution, approximately 90% of the levcromakalim (100 μM)-induced KATPcurrent remained at 8 min, even after the establishment of conventional whole-cell configuration. In conventional whole-cell configuration, glibenclamide suppressed the levcromakalim-induced KATPcurrents in a concentration-dependent manner (Ki=175 nM). Inclusion of 1 mM uridine 5′-diphosphate (UDP) in the pipette solution shifted the glibenclamide-sensitivity (Ki=640 nM) to the right in comparison with that in the absence of UDP (i.e., control). In contrast, using nystatin-perforated patch, glibenclamide inhibited the levcromakalim-induced KATPcurrents with two affinity sites (high-affinity site, Ki1=10 nM; low-affinity site, Ki2=9 μM). The concentration response curves regarding the inhibitory effects of KATPchannel pore blockers (Ba2+and flecainide) on the levcromakalim-induced KATPcurrents in conventional whole-cell recording nearly overlapped with those in nystatin-perforated patch recording. These results indicate that the glibenclamide-sensitivity of pig urethral KATPchannels in nystatin-perforated patch recording was significantly different from that in a conventional whole-cell configuration, and that the glibenclamide-sensitivity may be modified by some cytosolic factor(s).
影响因子：
56.9
作者：
INAGAKI, N;GONOI, T;BRYAN, J
通讯作者：
BRYAN, J