Reddy M M, Bell C L, Quinton P M
Division of Biomedical Sciences, University of California, Riverside 92521-0121, USA.
Am J Physiol. 1997 Aug;273(2 Pt 1):C426-33. doi: 10.1152/ajpcell.1997.273.2.C426.
The sweat gland has three distinct cell types: a myoepithelial (ME) cell, a beta-adrenergic-insensitive (beta-I) cell, and a beta-adrenergic-sensitive (beta-S) cell. Using intracellular microelectrodes, we sought to functionally identify the specific cell type(s) affected in cystic fibrosis (CF). We found that in CF secretory coils 1) the ME calls are unaffected, as indicated by normal cell membrane potentials and spontaneous and cholinergically induced depolarizing potentials, 2) the beta-I cells showed normal physiological properties, including a relatively smaller cell membrane potential (approx -25 mV) and a Ba(2+)-inhibitable cholinergic response, and, in contrast, 3) the beta-S cell is abnormal, as shown by the lack of a beta-adrenergically activated cystic fibrosis transmembrane conductance regulator (CFTR) Cl- conductance (GCl). Lack of CFTR GCl in this cell type does not affect either the magnitude of cell membrane potential (approx -56 mV) or the relative cell membrane GCl or the cholinergic response, as compared with that of normal beta-S cells. We conclude that, of the three cell types in secretory coil, only the beta-S cell is specifically affected in the CF secretory tissue of the human sweat gland.
肌上皮（ME）细胞、β-肾上腺素不敏感（β-I）细胞和β-肾上腺素敏感（β-S）细胞。我们使用细胞内微电极，试图从功能上确定囊性纤维化（CF）中受影响的特定细胞类型。我们发现，在CF分泌盘曲部：1）ME细胞未受影响，这由正常的细胞膜电位以及自发和胆碱能诱导的去极化电位表明；2）β-I细胞表现出正常的生理特性，包括相对较小的细胞膜电位（约-25mV）和Ba(2+)抑制的胆碱能反应，相比之下，3）β-S细胞是异常的，表现为缺乏β-肾上腺素激活的囊性纤维化跨膜传导调节因子（CFTR）Cl-电导（GCl）。与正常β-S细胞相比，这种细胞类型中CFTR GCl的缺乏既不影响细胞膜电位的大小（约-56mV），也不影响相对细胞膜GCl或胆碱能反应。我们得出结论，在分泌盘曲部的三种细胞类型中，只有β-S细胞在人汗腺的CF分泌组织中受到特异性影响。
