Figure 6. Reduced peripheral chemosensory drive in anesthetized mdx mice.

A) The Dejours test adapted to small rodents was utilized and the first 10 s of hyperoxia exposure were analyzed. The peripheral chemosensory drive was significantly affected in mdx mice compared to normal mice. B) The first 10 s of exposure to air-balanced hypercapnia or O₂-balanced hypercapnia were analyzed as the fast component of the HCVR. The HCVR induced by air-balanced hypercapnic gas mix (empty bar) was attenuated in normal mice compared to the HCVR induced by the hyperoxia-balanced hypercapnia mix (hatched bar). In the mdx mice, the early HCVR induced by air-balanced hypercapnic gas mix (gray bar) was similar to the early HCVR induced by the hyperoxia-balanced hypercapnia gas mix (filled bar). The analysis also showed a significant attenuation of the fast component of the HCVR in mdx mice compared to normal mice exposed to either air-balanced or hyperoxia-balanced hypercapnic gas mixtures. Mean ± SEM; * p<0.05, *** p<0.001. n = 4.