Effect of Ion Transport Inhibitors on the Bioelectric Responses of Guinea-Pig Tracheal Epithelium to Hypertonic Sodium Chloride Solution

Details

• Personal Author:
  Fedan, Jeffery S. ; Johnston RA ; Rengasamy A ; Van Scott MR
• Description:
  Previously our laboratory has shown that in the presence of serosally-added methacholine (MCh: 3x10^2 M), the application of hypertonic D-mannitol solution (120 mOsm) to the mucosal surface of guinea-pig tracheal segments mounted in Ussing chambers decreased the transepithelial short-circuit current (Isc). The purpose of this study was to determine if Isc responses to elevated tonicityare independent of the osmolyte used and to elucidate which epithelial ion channels and/or transporters are involved in the epithelial bioelectric response to elevated mucosal tonicity. In the presence of serosally-added MCh (3x10 M), exposure of the mucosal surface to modified Krebs-Henseleit solution made hypertonic with added NaCl (120 mOsm) decreased the Isc. Both amiloride (3x10^5 M; mucosal) and bumetanide (10^5 M; serosal) attenuated the decrease in Isc. Iberiotoxin (10 M: serosal and mucosal) a Ca activated K* channel blocker had no effect on Isc. The Isc increased rather than decreased in the presence of the Cl channel blocker. NPPB (10^-4 M: mucosal). The effect of ouabain (10 M: serosal) a Na-K*-ATPase inhibitor was also examined: however, it caused a progressive reduction in Isc which prevented assessment of the response to NaCl. These results suggest that apical Na channels and the basolateral Na-K-2Cl cotransporter are important in the epithelial bioelectric response to elevated mucosal tonicity while the role of apical Cl channels in this response is unclear. [Description provided by NIOSH]
• Subjects:
  Animals Chlorine Laboratories Methacholine Compounds Occupational Health Safety
• Keywords:
  Animal Studies Bioelectric Effects Chlorides Ion Transport Laboratory Animals Methacholines Sodium Compounds
• ISSN:
  0892-6638
• Document Type:
  Text
• Genre:
  Abstract or Summary ; Proceedings
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  15
• Issue:
  5
• NIOSHTIC Number:
  nn:20021342
• Citation:
  FASEB J 2001 Mar; 15(5):A861
• Federal Fiscal Year:
  2001
• Peer Reviewed:
  False
• Source Full Name:
  The FASEB Journal
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:872651858d9b7cd1fa60417cb334f52a481fb5e1e82b52d3c75bf4c0058512f864c040d14ffaaf65a77239046a38a8cac50c205e07338d4ff91b37d23eb54483
• Download URL:
  https://stacks.cdc.gov/view/cdc/198700/cdc_198700_DS1.pdf
• File Type:
  [PDF - 354.71 KB ]