Utilization in vitro and in vivo of glucose and glycerol by rat lung
Scholz, R.W.; Woodward, B.M.; Rhoades, R.A.
American Journal of Physiology 223(4): 991-996
1972
ISSN/ISBN: 0002-9513 PMID: 5075172 Document Number: 45564
Utilization of glucose-U-14C and glycerol-2-14C by lung tissue in vitro and in vivo was studied in normal rats and in rats deprived of food for 72 h. In the studies in vitro, glycerol oxidized to CO2 and incorporated into different lipid components by lung slices was increased as the glycerol concentration was increased from 1 to 25 mM. The addition of 5 mM glucose to the incubation medium decreased the apparent utilization of glycerol, suggesting that glucose and glycerol share a common metabolite pool in rat lung. Rats deprived for 72 h showed less glucose utilization by lung slices, whereas glycerol utilization was unaffected. In the studies in vivo glucose incorporated into lung lipids was significantly less in the deprived rats than in fed controls. The incorporation of glycerol-2-14C into lung lipids was increased significantly in the deprived rats at a time when plasma glycerol was increased threefold over control values. The results suggest that rat lung is capable of altering its metabolism to maintain biosynthesis of its essential lipid components during food deprivation.