Palmitate Incorporation in the Lungs of Dogs with Granulomatous Disease

Summary Moderate hypoxia did not influence the pulmonary incorporation of an intravenous dose of [1-14C]palmitate either in dogs with experimentally produced granulomatous disease or in normal controls. The lung weight in the diseased animals, was, on the average, double that of the controls. There was a proportionate increase in uptake of the radioactive label at 1 hr after infusion in the diseased lungs, hence the specific activity of labeled palmitate (counts per minute per gram of phospholipid) was no different in the two groups. Moreover, half the radioactivity of the phospholipids was recovered in palmitate separated from the phosphatidyl choline fraction in both diseased and normal lungs. Anatomic studies demonstrated increased numbers of Type II pneumocytes lining all alveolar air spaces in the diseased lung. Autoradiographic studies indicated the presence of labeled palmitate in the Type II cells, but not in the inflammatory cells of the granulomata. We conclude that the increased palmitate uptake in this disease in accounted for by the metabolic activity of the Type II pneumocytes. This study was supported by USPHS Grants HL-02001, HL-05443, Pulmonary SCOR Award HL-15088, and CA-11096. The authors wish to acknowledge the expert technical assistance of Nordal Mantaras, Lourdes Fernandez, Valeria Shishkoff, and Carin Colbjorinsen.