Clinical trials with
partial liquid ventilation demonstrate improvement in oxygenation, as well as some adverse side effects linked to the application of liquid
perfluorocarbons (PFCs) during
liquid ventilation. Thus, we examined the effects of systemic administration of PFC on
acute lung injury (ALI) induced by
lipopolysaccharide (LPS) and its effects on
heme oxygenase-1 (HO-1), a compound that provides potent cytoprotection against
lung injury. Rats were assigned to one of six groups (n = 8). Thirty minutes after they were challenged with LPS
aerosol inhalation,
perfluorohexane was given intraperitoneally every two hours. Ten hours after LPS inhalation, bronchoalveolar lavage fluid (BALF) and lung tissue were obtained for
enzyme linked
immunosorbent assay, histologic, and Western-blot analyses. The results showed that
perfluorohexane significantly decreased the wet to dry weight ratio,
malondialdehyde (MDA) production, and
myeloperoxidase (MPO) activity in the lung tissue. Also,
perfluorohexane reduced the total
protein content and levels of
tumor necrosis factor-alpha (
TNF-alpha) but increased the levels of the anti-inflammatory
cytokine interleukin-10 (IL-10) in the BALF, resulting in decreased
pulmonary edema and the infiltration of neutrophils into the lung tissues of LPS-treated rats. Furthermore,
perfluorohexane increased HO-1
protein production and stimulated HO-1 activity in the lung tissue. Pre-treatment with
Zinc protoporphyrin IX, an inhibitor of HO-1, decreased the protective effects of
perfluorohexane in rats. In summary, systemic
perfluorohexane alleviates LPS-induced
lung injury in rats, and HO-1 may be involved in the mechanism of this reduction.