Effects of perfluorocarbon administered at different time points on acute lung injury in rabbits

Abstract

Objective To evaluate the effects of perfluorocarbon administered at different time points on acute lung injury (ALI) in rabbits. Methods Eighteen New Zealand white rabbits, weighing 1.8-2.4 kg, aged 50-60 days, were randomly divided into 3 groups (n=6 each) using a random number table: ALI group, preventive administration of perfluorocarbon group (group PP), and therapeutic application of perfluorocarbon group (group PA). In group ALI, after the rabbits were mechanically ventilated for 60 min, ALI was induced with oleic acid 0.1 ml/kg injected via the internal jugular vein in three times within 5 min.In group PP, perfluorocarbon was inhaled at 2 ml·kg-1·h-1 for 60 min, and then ALI was induced.In group PA, after the rabbits were mechanically ventilated for 60 min, ALI was induced, and then perfluorocarbon was inhaled at 2 ml·kg-1·h-1 for 60 min.After 30 min stabilization (baseline, T0), at 60 min of ventilation or at 60 min after preventive administration of perfluorocarbon (T1), and at 30, 60, 90 and 150 min after ALI(T2-5), arterial blood samples were collected for blood gas analysis.Oxygenation index was calculated.Broncho-alveolar lavage fluid (BALF) was collected to determine the concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) (by ELISA) at T5.The animals were then sacrificed, and lungs were removed for determination of the expression of Toll-like receptor 4 (TLR4) and nuclear factor kappa B p65 (NF-κB p65) (by Western blot). Wet to dry lung weight ratio (W/D ratio) was calculated. Results Oxygenation index was significantly decreased at T2-5 than at T0 and T1 in the three groups.Compared to group ALI, oxygenation index was significantly increased at T2-5, the concentrations of TNF-α and IL-1β in BALF were decreased, W/D ratio was decreased, and the expression of TLR4 and NF-κB p65 was down-regulated in group PP, and oxygenation index was significantly increased at T5, and no significant change was found in the other parameters in group PA. Conclusion Preventive inhalation of perfluorocarbon 2 ml·kg-1·h-1 can mitigate ALI in rabbits. Key words: Fluorocarbons; Respiratory distress syndrome, adult