Abstract

The basic aim of the research plan is to study the interrelationships between the composition of the intracellular fluids and sodium transport across epithelia. Although the program is primarily based upon intracellular recording with ion-selective microelectrodes and reference micropipets, complementary studies will be performed with 3 1p nuclear magnetic resonance, electron probe X-ray microanalysis and computer simulations. In order to facilitate integration of the information obtained, most of the work will be conducted with a single epithelial model, split and whole frog skin. The principal objective will be to characterize the mode of apical sodium entry from the outer medium into the cell, and in particular to examine the putative role of intracellular sodium and calcium in regulating this entry. A second objective will be to define the electrokinetic and thermodynamic properties of the Na,K-exchange pump a the basolateral membranes. A third concern will be to examine the functional integration of the entire epithelium under three experimental conditions.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases (NIADDK)
Type
Research Project (R01)
Project #
5R01AM020632-08
Application #
3151317
Study Section
Physiology Study Section (PHY)
Project Start
1978-06-01
Project End
1987-05-31
Budget Start
1985-06-01
Budget End
1986-05-31
Support Year
8
Fiscal Year
1985
Total Cost
Indirect Cost

  Institution

Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104

  Publications

Civan, M M; Garty, H (1990) Toad urinary bladder as a model for studying transepithelial sodium transport. Methods Enzymol 192:683-97
Leibowich, S; DeLong, J; Civan, M M (1988) Apical Na+ permeability of frog skin during serosal Cl- replacement. J Membr Biol 102:121-30
Civan, M M; Cragoe Jr, E J; Peterson-Yantorno, K (1988) Intracellular pH in frog skin: effects of Na+, volume, and cAMP. Am J Physiol 255:F126-34
Civan, M M; Peterson-Yantorno, K; O'Brien, T G (1988) Insulin and phorbol ester stimulate conductive Na+ transport through a common pathway. Proc Natl Acad Sci U S A 85:963-7
Modiano, J F; Kelepouris, E; Kern, J A et al. (1988) Requirement for extracellular calcium or magnesium in mitogen-induced activation of human peripheral blood lymphocytes. J Cell Physiol 135:451-8
Civan, M M; Peterson-Yantorno, K; O'Brien, T G (1987) Diacylglycerols stimulate short-circuit current across frog skin by increasing apical Na+ permeability. J Membr Biol 97:193-204
Mauro, T; O'Brien, T G; Civan, M M (1987) Effects of TPA on short-circuit current across frog skin. Am J Physiol 252:C173-8
Garty, H; Civan, M M (1987) Ba2+-inhibitable 86Rb+ fluxes across membranes of vesicles from toad urinary bladder. J Membr Biol 99:93-101
Civan, M M; Peterson-Yantorno, K (1986) Intracellular pH regulation in frog skin: a 31P-nuclear magnetic resonance study. Am J Physiol 251:F831-8
Civan, M M; Williams, S R; Gadian, D G et al. (1986) 31P NMR analysis of intracellular pH of Swiss Mouse 3T3 cells: effects of extracellular Na+ and K+ and mitogenic stimulation. J Membr Biol 94:55-64

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