AJP - Cell Physiology, Vol 256, Issue 3 C478-C485, Copyright © 1989 by American Physiological Society
Dye-coupling compartments in the human eccrine sweat gland
C. J. Jones and P. M. Quinton
Division of Biomedical Sciences, University of California, Riverside 92521-0121.
The dye-coupling status of secretory and reabsorptive cells in
micro-dissected lengths of human eccrine sweat gland was investigated by
means of intracellular microiontophoresis of the fluorescent naphthalimide
dye Lucifer yellow CH (Mr 457), which passes through gap junctions. Cells
of the reabsorptive duct exhibited complete dye coupling between the apical
and basal layers of the epithelium. Conversely, cells of the secretory
tubule exhibited selective dye coupling. Of the three cell types present,
clear, dark, and myoepithelial, the dark cells were impaled and labeled
almost exclusively in the present study. These cells were observed either
as single cells or as dye-coupled groups of neighboring dark cells. In no
instance were dark cells observed to be dye coupled to clear cells or to
myoepithelial cells. Because myoepithelial cells are known to be dye
coupled exclusively to neighboring myoepithelial cells, the remaining clear
cells must either be uncoupled or show selective dye coupling to
neighboring clear cells. The significance of these findings is considered
with respect to the regulation and function of the different cell types
present in the human eccrine sweat gland.
