Progress in clinical and biological research
-
Prog. Clin. Biol. Res. · Jan 1987
Cl- permeability of sweat duct cell membranes: intracellular microelectrode analysis.
Cl- permeability in the reabsorptive sweat duct (RSD) epithelium from normal subjects was studied using electrophysiological techniques. The average basolateral membrane potential (Vb) of normal ducts was -36.8 +/- 0.8 mV and the average apical membrane potential (Va) was -27.2 +/- 0.8 mV (n = 45). Amiloride in the lumen of microperfused sweat ducts hyperpolarized Va by 34.3 +/- 3.1 mV and Vb by 25.7 +/- 3.1 mV (n = 12) with a small but significant increase in voltage divider ratio (Ra/Rb) from 4.2 +/- 0.8 to 5.0 +/- 0.8 (n = 8). ⋯ Alternatively, Va and Vb could be coupled through a Cl- sensitive paracellular shunt. These results are consistent with Cl- permeability in both apical and basolateral membranes of duct cells. However, the question of whether paracellular Cl- permeability is important in Cl- uptake cannot be determined from the present data.