Development of a novel chronic intermittent hypoxia chamber.

Objective: To develop a novel chronic intermittent hypoxia chamber for rat models.

Design: The intermittent hypoxia chamber included two animal cabins (28 × 20 × 15 cm) and a hypoxia chamber (80 × 80 × 60 cm) between them, as well as the actuating device. Pure nitrogen was fed into the hypoxia chamber continuously in order to keep the low O(2) concentration. Each animal cabin could move in and out of the hypoxia chamber with precise timing function. As a result, the animal cabins could be covered by the hypoxia chamber and got the same low O(2) concentration as in the hypoxia chamber and normal O(2) concentration as out of the hypoxia chamber. Twelve healthy, male Sprague-Dawley rats (200~250 g) were selected to test the effect of the intermittent hypoxia chamber. The O(2) concentration in the hypoxia chamber was 10 ± 0.5%, and the cycle time of intermittent hypoxia was 180 s (the hypoxia and normoxic time was 90 s, respectively). The hypoxia chamber ran 8 h per day. The arterial blood gas analysis (ABSA) of rats was conducted when the animal cabin was located inside and outside the hypoxia chamber.

Results: The chronic intermittent hypoxia chamber ran safely and reliably. The ABSA showed that the lowest PaO(2) was 35.75 ± 4.02 mmHg and the lowest SaO(2) was 68.62 ± 8.36% when the animal cabin was covered by the hypoxia chamber.

Conclusions: The chronic intermittent hypoxia chamber designed by us was suitable to establish a chronic intermittent hypoxia model for rats.