Evidence of two distinct epithelial cell types in primary cultures from human sweat gland secretory coil.

The human sweat gland secretory coil (SC) is comprised of myoepithelial (ME) and two types of secretory epithelial cells. The secretory cells include beta-adrenergic-sensitive (beta-S) cells [responsive to the beta-adrenergic agonist isoproterenol (IPR)] and beta-adrenergic insensitive (beta-I) cells. We have grown segments of SC in primary culture and found that under the conditions described here, only epithelial cells form outgrowths as indicated by morphological and physiological properties. As in the native SC epithelium, the secretory cells in primary culture were comprised of polygonal epithelial cells with a characteristic hyperpolarization of cell potentials (Vm) to cholinergic stimulation by mecholyl (magnitude of change of Vm = delta Vm = 21.5 +/- 1.3 mV, mean +/- SE, n = number of cells = 44). We have found both beta-S and beta-I cells as determined by unstimulated membrane potentials, sensitivity to IPR, and K+ conductance (GK+). The frequency distribution of unstimulated cells indicated two distinct populations of cells, one with high membrane potentials (Vm = -63 +/- 2.6 mV), which correlated with beta-S cells, and a second with low membrane potentials (Vm = -22 +/- 1.5 mV), which correlated with the beta-I cells. IPR depolarized the Vm of beta-S cells (delta Vm = 11.0 +/- 0.8 mV, n = 25) without affecting the Vm of beta-I cells.(ABSTRACT TRUNCATED AT 250 WORDS)