Pulmonary phospholipidosis in rats respiring air containing diesel particulates.
Rats chronically exposed to diesel particulates (dp) or given intratracheally a single dose of dp show increased levels of phospholipids in the lungs and in pulmonary lavage fluid. Pulmonary phospholipidosis is accompanied by increased lecithin levels and by increased palmitate content in lecithin of both lungs and pulmonary lavage fluid. A de novo increase of pulmonary and hepatic phospholipid (PL) formation was detected 5 days after rats were treated with dp. We hypothesize that a dp-stressed lung releases a pulmonary lipogenic factor (PLF), which stimulates hepatic lipogenesis. This was further tested by an in vitro study in which primary cultures of free hepatocytes were incubated with [2-14C]acetate and various molecular weight fractions of a pulmonary homogenate from rats. The results from these studies indicated that in rat lung homogenates a PLF exists of greater than 100,000 Da molecular mass. The results also indicate that respired air containing a dp concentration of greater than 750 micrograms dp/m3 of air would result in a mild phospholipidosis in the lung, whereas a dp dose in respired air of 250 micrograms dp/m3 of air for 2 years did not alter pulmonary PL content in rats.
Department of Surgery, University of Arizona Health Sciences Center, Tucson 85724.
C D
CD
Eskelson
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M
Chvapil
K A
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Strom
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Vostal
D000085:Acetates / Q000378:metabolism; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000378:metabolism; D002478:Cells, Cultured; D005227:Fatty Acids / Q000378:metabolism; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism*; D008171:Lung Diseases / Q000139:chemically induced* / Q000378:metabolism; D008297:Male; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D010578:Petroleum / Q000633:toxicity*; D010713:Phosphatidylcholines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D051381:Rats
D000085:Acetates; D005227:Fatty Acids; D010169:Palmitic Acids; D010578:Petroleum; D010713:Phosphatidylcholines; D010743:Phospholipids; D019308:Palmitic Acid