Effects of amiloride on sodium flux in isolated rat lungs
Cultured alveolar epithelial cell monolayers actively transport sodium (Na) from apical to basolateral surface. The process can be stimulated by terbutaline and inhibited by amiloride. In this study, the isolated perfused rat lung was used to investigate the presence of these phenomena in intact mammalian alveolar epithelium. Adult male Sprague-Dawley rats (250-350 g) were tracheostomized and ventilated with 95%O/sub 2/:5% CO/sub 2/. Two ml Krebs-Ringer-bicarbonate solution (KRB) with or without terbutaline (5 x 10/sup -6/M) were instilled into the trachea Lungs were then perfused via the pulmonary artery with KRB. At t=0, 3 ml KRB containing 0.6uCi /sup 22/Na and 0.6uCi /sup 14/C-sucrose were lavaged into the trachea. Samples of the recirculated perfusate were taken periodically thereafter. At t=20 min, amiloride (10/sup -3/M) was added to the perfusate. Samples were counted and apparent permeability x surface area products (PA) calculated. Control PA for /sup 22/Na was 3.72 (+/-0.15) x 10/sup -4/ ml/s. Amiloride inhibited /sup 22/Na flux by 30% (PA=2.62(+/-0.17) x 10/sup -4/ ml/s). Terbutaline stimulated /sup 22/Na flux by 59% (PA=5.92(+/-0.46) x 10/sup -4/ ml/s). Amiloride inhibited this pre-stimulated /sup 22/Na flux by 46% (PA=3.19(+/-0.37) x 10/sup -4/ ml/s). PA for sucrose was unchanged by any of these drugs. These data are consistent with the presence of a regulable component of active sodium transport from airspace to vascular space in intact mammalian lungs.
- Research Organization:
- Will Rogers Institute Pulmonary Research Lab., Los Angeles, CA
- OSTI ID:
- 6937015
- Report Number(s):
- CONF-8604222-; TRN: 87-008597
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:4; 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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Related Subjects
DIURETICS
BIOLOGICAL EFFECTS
SODIUM COMPOUNDS
MEMBRANE TRANSPORT
CARBON 14 COMPOUNDS
EPITHELIUM
LAVAGE
LUNGS
PERFUSED ORGANS
RATS
SACCHAROSE
SODIUM 22
TRACER TECHNIQUES
TRACHEA
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
DISACCHARIDES
DRUGS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
NUCLEI
ODD-ODD NUCLEI
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
RESPIRATORY SYSTEM
RODENTS
SACCHARIDES
SODIUM ISOTOPES
TISSUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
550201* - Biochemistry- Tracer Techniques