Effects of SNP, ouabain, and amiloride on electrical potential profile of isolated
sheep pleura.
Hatzoglou, C. H., K. I. Gourgoulianis, and P. A. Molyvdas.
1General Hospital of Larissa and 2Department of Physiology, Medical School,
University of Thessaly, 412 22 Larissa, Greece
APStracts 8:0004A, 2001.
The fluid and solute transport properties of pleural tissue were studied by using
specimens of intact visceral and parietal pleura from adult sheep lungs. The samples were
transferred to the laboratory in a Krebs-Ringer solution at 4°C within 1 h from the death
of the animal. The pleura was then mounted as a planar sheet in a Ussing-type chamber.
The results that are presented in this study are the means of six different experiments. The
spontaneous potential difference and the inhibitory effects of sodium nitroprusside,
ouabain, and amiloride on transepithelial electrical resistance (RTE) were measured. The
spontaneous potential difference across parietal pleura was 0.5 ± 0.1 mV, whereas that
across visceral pleura was 0.4 ± 0.1 mV. RTE of both pleura was very low: 22.02 ± 4.1
O•cm2 for visceral pleura and 22.02 ± 3.5 O•cm2 for parietal pleura. There was an
increase in the RTE when sodium nitroprusside was added to the serosal bathing solution
of parietal pleura and to the serosal or mucosal bathing solution in visceral pleura. The
same was observed when ouabain was added to the mucosal surface of visceral pleura
and to either the mucosal or serosal surface of parietal pleura. Furthermore, there was an
increase in RTE when amiloride was added to the serosal bathing solution of parietal
pleura. Consequently, the sheep pleura appears to play a role in the fluid and solute
transport between the pleural capillaries and the pleural space. There results suggest that
there is a Na+ and K+ transport across both the visceral and parietal pleura.
Received 28 December 1999; accepted in final form 13 October 2000
APS Manuscript Number A1084-9.
Article publication pending J Appl Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 29 January 2001