The properties of single Ca2+-activated K+ (BK) channels in neonatal rat intracardiac neurons were investigated using the patch-clamp recording technique. In symmetrical 140 mM K+, the single-channel slope conductance was linear in the voltage range -60/+60 mV. and was 207+/-19 pS. Na+ ions were not measurably permeant through the open channel. Channel activity increased with the cytoplasmic free Ca2+ concentration ([Ca2+],) with a Hill plot giving a half-saturating [Ca2+] (K-0.5) of 1.35 muM and slope of congruent to3. The BK channel was inhibited reversibly by external tetraethylammonium (TEA) ions, charybdotoxin, and quinine and was resistant to block by 4-aminopyridine and apamin. Ionomycin (1-10 muM) increased BK channel activity in the cell-attached recording configuration. The resting activity was consistent with a [Ca2+](i)
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机译：使用膜片钳记录技术研究了新生大鼠心内神经元中单个Ca2 +激活的K +（BK）通道的特性。在对称的140 mM K +中，单通道斜率电导在-60 / + 60 mV电压范围内呈线性。并且为207 +/- 19pS。 Na +离子无法通过开放通道渗透。通道活性随细胞质中游离Ca2 +浓度（[Ca2 +]，）的增加而增加，希尔图显示半饱和[Ca2 +]（K-0.5）为1.35μM，斜率等于3。 BK通道可逆地被外部四乙铵（TEA）离子，charybdotoxin和奎宁抑制，并且对4-氨基吡啶和木瓜蛋白酶具有抗性。依诺霉素（1-10μM）在细胞附着的记录配置中增加了BK通道活性。静息活动与[Ca2 +]（i）一致
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