Stea A, Nurse C A
Department of Biology, McMaster University, Hamilton, Ont., Canada.
Neurosci Lett. 1991 Nov 11;132(2):239-42. doi: 10.1016/0304-3940(91)90310-p.
In this study we compared the effects of physiological bicarbonate/CO2-buffered media (BBM) with the commonly used N-2-hydroxyethylpiperazine-N'-2-ethane-sulfonic acid (HEPES)-buffered media (HBM) on whole-cell currents in cultured rat arterial chemoreceptors (i.e. glomus cells) using the perforated-patch technique. Two separate effects were observed on switching from HBM to BBM. First, in the majority of cells tested (31 of 36) there was an increase in the leakage conductance (ca. 5 fold) and a concomitant increase in channel noise, which in preliminary studies appears to arise from the opening of large-conductance anion channels. Second, there was a reversible decrease in voltage-activated outward K+ current which we attribute to cytoplasmic acidification, catalysed by carbonic anhydrase in glomus cells.
在本研究中，我们使用穿孔膜片钳技术，比较了生理性碳酸氢盐/二氧化碳缓冲介质（BBM）与常用的N-2-羟乙基哌嗪-N'-2-乙烷磺酸（HEPES）缓冲介质（HBM）对培养的大鼠动脉化学感受器（即球细胞）全细胞电流的影响。从HBM转换为BBM时观察到两种不同的效应。首先，在大多数测试细胞（36个中的31个）中，漏电导增加（约5倍），同时通道噪声增加，在初步研究中，这似乎是由大电导阴离子通道的开放引起的。其次，电压激活的外向钾电流出现可逆性降低，我们将其归因于球细胞中碳酸酐酶催化的细胞质酸化。
