The overall goal of this project is to determine the membrane mechanisms for intracellular pH regulation in human airway epithelial cells. Intracellular pHi regulates a variety of cellular processes including the function and activity of many ion transport mechanisms. Cystic fibrosis (CF) is a single gene defect which affects several ion transport pathways including the apical Na and Cl permeabilities, the Na, K-ATPase and possibly the basolateral K permeabilities. Intracellular pHi is a CF might be associated with a defect in the regulation of Intracellular pHi- regulatory mechanisms in human airway epithelium.
The specific aims of the proposed research are: (1) To make reliable estimation of pHi in cultured normal and CF nasal epithelium. (2) to determine whether specific H and HCO3 transport pathway[s] ((Na/H exchange, Cl/HCO3 exchange, Na-HCO3 cotransport, and conductive H and HCO3 pathways) contribute to pHi regulation in nasal epithelium. The chemical and hormonal regulation of these mechanisms will also be determined. (3) To determine whether the ion transport pathways responsible for the control of Intracellular pHi are affected by CF. The method centers around the use of pH-sensitive fluorescent probes, microspectrofluorimetry, and digital image processing to measure pHi in single cultured human nasal cells.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL044173-02
Application #
3362955
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1990-07-01
Project End
1993-06-30
Budget Start
1991-07-01
Budget End
1992-06-30
Support Year
2
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Paradiso, Anthony M; Coakley, Raymond D; Boucher, Richard C (2003) Polarized distribution of HCO3- transport in human normal and cystic fibrosis nasal epithelia. J Physiol 548:203-18
Paradiso, A M; Ribeiro, C M; Boucher, R C (2001) Polarized signaling via purinoceptors in normal and cystic fibrosis airway epithelia. J Gen Physiol 117:53-67
Paradiso, A M; Brown, H A; Ye, H et al. (1999) Heterogeneous responses of cell Ca2+ in human airway epithelium. Exp Lung Res 25:277-90
Paradiso, A M (1997) ATP-activated basolateral Na+/H+ exchange in human normal and cystic fibrosis airway epithelium. Am J Physiol 273:L148-58
Barker, P M; Brigman, K K; Paradiso, A M et al. (1995) Cl- secretion by trachea of CFTR (+/-) and (-/-) fetal mouse. Am J Respir Cell Mol Biol 13:307-13
Paradiso, A M (1992) Identification of Na(+)-H+ exchange in human normal and cystic fibrotic ciliated airway epithelium. Am J Physiol 262:L757-64
Van Scott, M R; Paradiso, A M (1992) Intracellular Ca2+ and regulation of ion transport across rabbit Clara cells. Am J Physiol 263:L122-7
Paradiso, A M; Cheng, E H; Boucher, R C (1991) Effects of bradykinin on intracellular calcium regulation in human ciliated airway epithelium. Am J Physiol 261:L63-9