Effect of chronic hypoxia on fibronectin in plasma, bronchoalveolar lavage fluid and liver of rats.

The present study was undertaken to measure fibronectin (FN) concentration in plasma and bronchoalveolar lavage fluid (BALF) with an enzyme linked immunosorbent assay (ELISA) method, to observe the distribution of FN in liver with an immunohistochemical stain method and to investigate the effect of chronic normobaric hypoxia on them in experimental rats. The results showed that chronic hypoxia caused a significant decrease in plasma FN concentration while BALF FN concentration and the distribution of FN in the liver were not significantly affected, suggesting that the change in FN in the lower respiratory tract can not be reflected by the change in plasma FN concentration and that the decrease in plasma FN concentration can not be attributed to the change in liver FN secretion. The decrease in plasma FN concentration may lead to a decrease in the defence ability of the body and may contribute to the development of hypercoagulability observed in some patients with chronic hypoxia.