EXPERIMENTAL RADIATION PNEUMONITIS .3. PHOSPHOLIPID STUDIES ON THE LUNGS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 93  (4) , 627-637
Abstract
Mice received 2400 rads in 2 fractions to the thorax; 4 mo. later when radiation pneumonitis occurred, aspects of their phospholipid metabolism were studied and compared to those of unirradiated mice. In the lung tissue there was a consistent and significant increase in the total phospholipids and particularly in the amount of PC [phosphotidyl choline]. The proportion of the latter which was disaturated remained constant. In the lavaged AF [aveolar fluid] the increase was smaller and not significant, the degree of disaturation again remaining constant. Isotope labeling in vivo with 3H-glycerol, 14C-palmitate and 3H-choline indicated significantly increased incorporation of each of these precursors into PC and most other phospholipids. This was not due to changes in nutrition, altered precursor pool sizes, or redistribution of isotope insofar as could be determined. Histologic studies showed the type 2 cells to be large and filled with numerous enlarged lamellar bodies. Phospholipid synthesis probably is enhanced in radiation pneumonitis and that the fall in compliance of the alveolar surface layer is not likely to be due to surfactant deficiency in this model.