An adaptation for exhaled breath condensate collection in rabbits.

Aim: To set up and test the feasibility of a handmade apparatus adapted for exhaled breath condensate (EBC) collection in medium-sized animals.
Materials and Methods: The apparatus was produced using an 18-mm thick u-shaped borosilicate glass. The u-shaped tube body is 25 cm in diameter, and the horizontal portions are 12 cm in diameter. The base consists of a tube joint 14/20 or 14 mm thick by 20 cm in diameter, and has a length of 5 cm. This has a hole that is plugged for condensate flow to a 1.5 mL polypropylene microtube that stores the condensate during collection. Was placed inside a styrofoam box and immersed in crushed ice and salt to ensure cooling. The temperature was monitored and maintained throughout the collection at -10°C. One of the outputs of the u-shaped tube was connected to the expiratory limb of the ventilator.
Results: An experimental model of ALI, induced by oleic acid (OA) was adopted to determine the concentration of biomarkers of oxidative stress: malondialdehyde (MDA), glutathione (GSH), and nitrite/nitrate (NOx). The proposed model allows measurement of NOx, MDA, and GSH. However, the NOx and MDA levels in the EBC were not significant. It was only possible to observe an upward trend, which suggests a temporal evolution of the presence of these markers in the EBC.
Conclusion: The EBC collection method adapted is effective to generate sufficient content that allows to determine the levels of different biomarkers, such as NOx, MDA, and GSH, that are involved in oxidative and inflammatory stress processes during respiratory diseases.