Incorporation of palmitate-1-14C into lung tissue and "alveolar" lecithin

Thomas, Theresa M.; Rhoades, Rodney A.

doi:10.1152/ajplegacy.1970.219.6.1535

Cited by 52 publications

(16 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Newly synthesized radioactive protein is released by lung slices, and this release is inhibited by low temperature or cyanide and stimulated by epinephrine, which indicates that this release is an active secretory process (13). In vivo studies are consistent with a precursor-successor relationship between cellular lipid (17)(18)(19)(20)(21) and protein, including protein in a surfaceactive fraction (22), and similar fractions obtained by lung lavage.…”

Section: Introductionsupporting

confidence: 76%

In vivo protein secretion by lung. Evidence for active secretion and interspecies differences.

Massaro¹

1975

J. Clin. Invest.

View full text Add to dashboard Cite

A B S T R A C T The present study is an attempt to determine (a) if the lung actively secretes protein into the surface-active fraction of lung lavage returns; (b) if there are interspecies differences in this secretory activity; and (c) if the amount of nonradioactive protein in the lavage surface-active fraction shows interspecies variation.I found that pilocarpine stimulates the release of radioactive protein into the lavage surface-active fraction of rabbits and that this pilocarpine effect is completely blocked by atropine. Inhibition of lung oxygen consumption by iodoacetate is associated with a dosedependent inhibition of the pilocarpine-induced secretion. Microtubules may be involved in this secretory process because colchicine inhibits the pilocarpine effect.Of the radioactive protein in the total surface-active fraction (tissue plus lavage returns), a greater percent appears in the lavage surface-active fraction at 2 and 4 h, after a pulsed injection of [U-'4C]leucine, in the mouse than in the rat, which in turn has a greater amount than the rabbit. There is also a difference in the amount of nonradioactive protein per square meter of alveolar surface area in the lavage surface-active fraction of different species: mouse> rat> rabbit> cat> dog. The amount of nonradioactive protein per square meter of alveolar surface area in the lavage surfaceactive fraction is directly proportional to the species respiratory rate; the log of the nonradioactive protein in the lavage surface-active fraction is inversely proportional to the log of the species alveolar diameter.

show abstract

Section: Introductionsupporting

confidence: 76%

In vivo protein secretion by lung. Evidence for active secretion and interspecies differences.

Massaro¹

1975

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…The lung readily incorporates labeled precursors such as palmitate into phospholipids (1,4,29,30,33). It is known also that fatty acids are synthesized rapidly by the lung and utilized in the synthesis of phospholipids by the lung (4,7,29,30,33). Kilburn and associates (17) have reported that biosynthesis of phosphatidylcholine in the lung with papain-induced lesions proceeded at the same rate as in controls, although the protein synthesis increased.…”

Section: Discussionmentioning

confidence: 99%

“…A rapid rate of phospholipid synthesis in lung tissue appears to be vital for continuous replenishment of the phospholipids in the surfactant material on the alveolar surface (1,30). It has been suggested that alveolar wash lipids are derived from lung tissue lipids (22,27,29). However, there are few studies on the alterations of phospholipid metabolism in the lung and the alveolar wash lipids in the lesioned lung.…”

mentioning

confidence: 99%

Experimental Pneumonitis: Changes in the Phospholipid Metabolism of the Lung of Guinea Pigs and Rats

Ito

Takeuchi

Masuno

et al. 1977

Microbiology and Immunology

View full text Add to dashboard Cite

Changes of the metabolism of lung phospholipids and alveolar wash lipids were studied in guinea pigs and rats with experimental pneumonitis produced by the injection of complete Freund's adjuvant. The amount of total lipid obtained by lung lavage decreased significantly in contrast to a marked increase in the content of total protein in treated animals. Among the lipids in the pulmonary washings, only phospholipids were strikingly reduced, and free fatty acids were increased some what. However, the composition of phospholipids was not affected by the treatment. The in vitro incorporation of 1-14C-acetate into the total lipid and phospholipids in the lung with pneumonitis was slightly lower compared to controls, but the difference was not significant. The in vitro 1-14C-palmitic acid incorporation into phospholipids of the lesioned lung, was also similar to that in controls. Thus, phospholipid biosynthesis in the lung was not affected by pneumonitis. On the other hand, the in vitro activity of total phospholipase in rat lung with experimental pneumonitis was enhanced significantly. These results suggest that phospholipase activity is increased in the diseased lung and this may participate in the process of the inflammatory reaction. The possible role of activated macrophages in the in flammatory response of the lung is discussed.

show abstract

“…Following injection of C14 palmitate in vivo, radioactivity accumulates in lung tissue and reaches peak values in about 1 hr, followed by a gradual decline of radioactivity with half-time of approximately 12 hr (13). The appearance of radioactivity in alveolar lavage material is delayed relative to lung tissue (peak values are reached after approximately 6 hr), but declines at a similar rate as observed in lung tissue (13). These results suggest movement of palmitate from tissue to alveolar space with a relatively rapid turnover.…”

Section: Lung Surfactantmentioning

confidence: 99%

Normal and pathologic biochemistry of the lung.

Fisher¹

1976

Environ Health Perspect

View full text Add to dashboard Cite

The lung is an important metabolic organ. Glucose provides the major source of substrate. Oxidative pathways are active and are required to maintain normal tissue energy stores. Synthetic activity in the lung is extensive and related mainly to synthesis of dipalmitoyl lecithin and other components of the lung surfactant system. The lung plays an important role in the metabolism of xenobiotics and endogenous hormones leading to degradation as well as activation of important biologic properties.Only recently has the lung been recognized as an important metabolic organ rather than just a tissue for passive gas exchange. A major reason for the delay in appreciation of the metabolic role of the lung is related to its structure and anatomic relationships. The lung, although filling most of the thoracic cavity, actually comprises only 1% of the body weight, and approximately 30% of that weight is due to contained blood. Further, the blood flow to the lung comprises the entire cardiac output making it the most richly perfused organ in the body. Because of the high blood flow in relation to metabolizing tissue mass, arteriovenous differences of most metabolites cannot be measured across the lung in situ. Consequently, it has been necessary to develop in vitro models for study of lung metabolism. One model that has been extensively used is the isolated perfused lung preparation. Perfusion of the lung with artificial media removes the red cells from the pulmonary capillaries and results in tissue with a completely white appearance. Additional models to study lung metabolism are tissue slices and preparations of subcellular organelles.

show abstract

Incorporation of palmitate-1-14C into lung tissue and "alveolar" lecithin

Cited by 52 publications

References 0 publications

In vivo protein secretion by lung. Evidence for active secretion and interspecies differences.

In vivo protein secretion by lung. Evidence for active secretion and interspecies differences.

Experimental Pneumonitis: Changes in the Phospholipid Metabolism of the Lung of Guinea Pigs and Rats

Normal and pathologic biochemistry of the lung.

Contact Info

Product

Resources

About