Lung Hyperpermeability and Changes in Biochemical Constituents in Bronchoalveolar Lavage Fluids Following X Irradiation of the Thorax

Groups of rats were administered different doses of X rays (7.5 and 15 Gy), and the effect on the permeability of their lungs was evaluated during a time frame within which radiation pneumonitis develops. Sham-exposed animals served as controls. End points surveyed included lung weight and increases in the total protein in the lavage fluid. To obtain more detailed information about hyperpermeability and to examine some specific protein changes that occur in the lung's fluid in response to X irradiation, the lavage fluids were subjected to a reverse-phase HPLC technique that resolves 11 fractions quantitatively, including transferrin, albumin, and immunoglobulins derived from blood, as well as eight other protein and nonprotein constituents that appear to be derived from the lung (fractions 1, 2, 6-11). The earliest change following the 7.5-Gy dose was a decrease in fraction 6 at 1 week after exposure. As of Week 5, the lung weight and total protein in the lavage fluid were all normal, while the HPLC analy...