부산대학교 도서관

Neurotrophins and their receptors have important roles in survival of neural tissues that may extend to cells of non neural origin. Their presence and response to hyperoxia-induced lung injury has not been fully characterized. We randomized four day old rat pups to breath either room air or hyperoxia (FIO2=95%) for 1, 3, 6 and 10 days. By Western blot we found a significant decline in the hyperoxic-exposed group of Neurotrophin-3 (NT-3) and its high affinity receptor TRK-C, beginning at day 3 with maximal decline at day 6. NT-3 and TRK-C are widely distributed in the lungs both in the airways and air sacs as seen by immunohistochemistry. We repeated the experiment using human fetal lung fibroblast under culture conditions exposed to 95% oxygen and found the same results. NT-3 and its high affinity TRK-C receptor level declined significantly by 4 hours and were undetectable by 12 hours of exposure as determined by Western blot. We conclude that hyperoxia decreased lung expression of NT-3 and its receptor. The findings may have implications for lung growth and development.