The granulocyte colony-stimulating factor produced in the human lung and its effect on liquid movement in the rabbit lung.

Levels of the granulocyte colony-stimulating factor (G-CSF) were determined in the plasma and resected lung tissue from patients who underwent pulmonary resection. Moreover, the effect of recombinant human (rh) G-CSF on the permeability of pulmonary endothelium and on liquid clearance from the alveolar spaces was investigated in rabbits. The plasma levels of G-CSF increased from 30 pg/ml preoperatively to 409 +/- 236 pg/ml 3 h postoperatively (P < 0.05), while the levels of G-CSF in the resected lung tissue were increased in the alveolar fluid, to 1,834 +/- 1,054 pg/ml, and in the pulmonary blood, to 5,466 +/- 2,019 pg/ml. It was found that rh G-CSF 25 micrograms administered into the subcutaneous tissue of rabbits increased extravascular lung water to 3.45 +/- 0.26 vs 2.98 +/- 0.20 in control experiments (P < 0.05); however, rhG-CSF 0.75 microgram/kg administered into the alveolar spaces did not affect liquid clearance from the alveolar spaces. The findings of this study led us to conclude that G-CSF is synthesized in the human lung and increases the permeability of pulmonary endothelium, but not liquid clearance across the alveolar epithelium.