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Title: p-aminohippurate transport in the airways: Role of Na sup + and HCO sub 3 -

Journal Article · · American Journal of Physiology; (USA)
OSTI ID:6983968
 [1]
  1. Univ. of Connecticut Health Center, Farmington (USA)

The role of Na{sup +} and HCO{sub 3}- in the transport of p-aminohippurate (PAH) across the canine tracheal epithelium was investigated using Ussing chamber techniques and radiolabeled PAH. Under control conditions, net PAH absorption or a tendency toward net PAH absorption was observed. Neither amiloride (10(-4) M), furosemide (10(-3) M), ouabain (2 x 10(-4) M), nor Na+ substitution of the Ringer solution with choline had any effect on unidirectional PAH fluxes. When the Ringer solution was replaced with a HCO{sub 3}(-)-free solution, net PAH absorption was consistently observed. In HCO{sub 3}(-)-free experiments, unidirectional PAH absorptive fluxes were inhibited by mucosal addition of either of the stilbene derivatives, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS, 10(-4) M) or 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS, 10(-4) M). DIDS was more effective than SITS and was also effective in inhibiting PAH absorption in tissues bathed in Ringer solution. Submucosal DIDS or SITS had no effect on PAH fluxes either in HCO{sub 3}(-)-free or Ringer experiments. We conclude that PAH transport in canine tracheal epithelium occurs by a HCO{sub 3}(-)-PAH exchange process located on the luminal membrane. PAH transport is not Na{sup +} dependent but is inhibited by both DIDS and SITS.

OSTI ID:
6983968
Journal Information:
American Journal of Physiology; (USA), Vol. 257; ISSN 0002-9513
Country of Publication:
United States
Language:
English