Na/sup +/-dependent transport of /sup 14/C-L-lysine across bullfrog alveolar epithelium
Transepithelial transport of the basic amino acid L-lysine has been studied utilizing the isolated intact bullfrog lung mounted in the Ussing chamber. Lungs were excised from doubly pithed bullfrogs and sandwiched between two hemichambers. /sup 14/C-(U)-L-lysine was added to the upstream reservoir of amphibian Ringer solution, while the tissue was short-circuited. Two lungs from the same animal were used simultaneously to determine the two opposite unidirectional fluxes. Downstream and upstream radioactivities were assayed and used to estimate the apparent permeability (P) of the labeled lysine. Results indicate that the apparent P of /sup 14/C-L-lysine measured in the alveolar (M) to the pleural (S) direction is 19.06 (+- 2.84) x 10/sup -7/ cm/s and P in the S to M direction is 3.29 (+- 0.02) x 10/sup -7/ cm/s. When the 100 mM NaCl in the bath was replaced by 110 mM choline chloride, the flux of /sup 14/C-L-lysine from the alveolar to the pleural side decreased to the same value as that in the opposite direction. The flux from the pleural to the alveolar direction in the absence of Na/sup +/ did not change. These results suggest that the alveolar epithelium exhibits Na/sup +/-dependent amino acid (L-lysine) transport in the M->S, but not in the S->M, direction.
- Research Organization:
- Univ. of California, Los Angeles
- OSTI ID:
- 5450915
- Report Number(s):
- CONF-8604222-; TRN: 86-028365
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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EPITHELIUM
PERMEABILITY
LYSINE
MEMBRANE TRANSPORT
CARBON 14 COMPOUNDS
CATIONS
FROGS
LUNGS
SODIUM COMPOUNDS
TRACER TECHNIQUES
ALKALI METAL COMPOUNDS
AMINO ACIDS
AMPHIBIANS
ANIMAL TISSUES
ANIMALS
AQUATIC ORGANISMS
BODY
CARBOXYLIC ACIDS
CHARGED PARTICLES
IONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RESPIRATORY SYSTEM
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques