Changes in phospholipid biosynthetic enzymes in type II cells and alveolar macrophages isolated from rat lungs after NO/sub 2/ exposure

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Toxicol. Appl. Pharmacol.; (United States)

DOI:https://doi.org/10.1016/0041-008X(82)90296-4· OSTI ID:5604832

Wright, E S; Vang, M J; Finkelstein, J N; Mavis, R D

The activities of phospholipid biosynthesizing enzymes and subcellular marker enzymes were measured in type II cells and alveolar macrophages isolated from rat lungs 48 hr after exposure to air or 40 ppm NO/sub 2/. DNA and protein increased in cell fractions from NO/sub 2/-exposed lungs, but NO/sub 2/ exposure had no effect on the percentage of type II cells in isolated cell fractions. A general increase in cell content of biosynthetic enzyme activities (units/mg DNA) was observed in type II cells from NO/sub 2/-exposed rats, but no change was detected in the activity of the microsomal marker enzyme, NADPH cytochrome c reductase. Glycerolphosphate acyltransferase and choline phosphotransferase increased 171 and 168%, respectively, and phosphatidate phosphohydrolase increased 69%. Glycerolphosphate phosphatidyltranferase increased 143% and succinate cytochrome c reductase, the mitochondrial marker enzyme, increased 111%. Type II cells from control lungs contained a greater than threefold higher activity of the phosphatidylglycerol synthesizing enzyme, glycerolphosphate phosphatidyltransferase, compared to alveolar macrophages, and comparable activities of the enzymes of phosphatidylcholine synthesis and of the microsomal and mitochondrial reductases. Exposure to NO/sub 2/ resulted in a significant increase in NADPH cytochrome c reductase activity (46%) in macrophages, but no change in any biosynthetic enzymes. The increases in protein content and activity of phospholipid biosynthetic enzymes in type II cells are consistent with a general hypertrophy of type II cells which includes stimulation of surfactant phospholipid biosynthesis 2 days after exposure to NO/sub 2/ when type II cell proliferation is occuring.

• Research Organization: Univ. of Rochester School of Medicine and Dentistry, NY
• DOE Contract Number: AC02-76EV03490
• OSTI ID: 5604832
• Journal Information: Toxicol. Appl. Pharmacol.; (United States), Journal Name: Toxicol. Appl. Pharmacol.; (United States) Vol. 66; ISSN TXAPA
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOSYNTHESIS
BODY
CHALCOGENIDES
CHEMICAL ANALYSIS
CONNECTIVE TISSUE CELLS
ENZYME ACTIVITY
ENZYMES
ESTERS
LIPIDS
LUNGS
MACROPHAGES
MAMMALS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PHAGOCYTES
PHOSPHOLIPIDS
PROTEINS
RATS
RESPIRATORY SYSTEM
RODENTS
SOMATIC CELLS
SYNTHESIS
VERTEBRATES