INTRAVENOUS KERATINOCYTE GROWTH-FACTOR PROTECTS AGAINST EXPERIMENTAL PULMONARY INJURY

Keratinocyte growth factor (KGF) administered by intratracheal instill ation is well documented to stimulate the proliferation of alveolar an d bronchial cells. In the present study, intravenous KGF was also show n to stimulate the proliferation of alveolar and bronchial cells in mi ce and rats, although to a lesser degree than intratracheal KGF. Despi te the decreased potency of intravenous KGF on pulmonary cell 5-bromo- 2'-deoxyuridine incorporation compared with intratracheal KGF, intrave nous KGF was very effective in preventing experimental bleomycin-induc ed pulmonary dysfunction, weight loss, and mortality in either mice or rats and experimental hyperoxia-induced mortality in mice. The effect iveness of intravenous administration of KGF in preventing lung injury suggests that the mechanisms of the protective effect of KGF may invo lve more than pulmonary cell proliferation and also suggests the poten tial use of systemic KGF for clinical trials in settings of pulmonary injury.