Lactate metabolism in the fetal rabbit lung

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5232933

Engle, M J; Brown, D J; Dooley, M

Lactate is frequently overlooked as a potential substrate for the fetal lung, even though it is present in the fetal circulation in concentrations as high as 8 mM. These high concentrations, coupled with the relatively low levels of glucose in the fetal blood, may indicate that lactate can substitute for glucose in pulmonary energy generation and phospholipid synthesis. A series of experiments was therefore undertaken in order to investigate the role of lactate in perinatal pulmonary development. Explants from 30 day gestation fetal rabbit lungs were incubated in Krebs-Ringer bicarbonate buffer supplemented with 3 mM (U-/sup 14/C)-glucose and varying levels of lactate. In the absence of medium lactate, fetal rabbit lung explants were capable of producing lactate at a rate of approximately 200 etamoles/mg protein/hour. The addition of lactate to the bathing medium immediately reduced net lactate production and above 4 mM, fetal rabbit lung explants became net utilizers of lactate. Media lactate concentrations of 2.5 mM, 5 mM and 10 mM also decreased glucose incorporation into total tissue disaturated phosphatidylcholine by approximately 20%, 35%, and 45%, respectively. Glucose incorporation into surfactant phosphatidylcholine was also reduced by approximately 50%, when lactate was present in the incubation medium at a concentration of 5 mM. Additional experiments also revealed that fetal lung lactate dehydrogenase activity was almost twice that found in the adult rabbit lung. These data indicate that lactate may be an important carbon source for the developing lung and could be a significant component in the manufacture of surfactant phosphatidylcholine during late gestation.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 5232933
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ANIMALS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACID SALTS
ENZYME ACTIVITY
ENZYMES
ESTERS
FETUSES
GLUCOSE
HEXOSES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LACTATES
LIPIDS
LUNGS
MAMMALS
METABOLISM
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
OXIDOREDUCTASES
PHOSPHOLIPIDS
RABBITS
RESPIRATORY SYSTEM
SACCHARIDES
TRACER TECHNIQUES
TRANSPLANTS
VERTEBRATES