Fig. 3: Three-month Slc6a8−/y mice show increased VO2, diminished exercise capacity, and shorter time to exhaustion.

Indirect calorimetry was performed using Oxymax CLAMS system. Slc6a8−/y mice show increased normalized food intake (a) and oxygen consumption (VO2) (c) despite mean activity (b) being roughly equivalent. Body composition determined by EchoMRI demonstrate decreased (d) weight, (e) fat mass, (g) lean mass, and (h) % lean mass in Slc6a8−/y, while % fat mass (f) appeared greater in Slc6a8−/y mice. Exercise testing shows Slc6a8−/y mice have diminished (i) distance traveled and (j) work expended during exercise. This correlates with much shorter (k) time to exhaustion during excise. Data are displayed as mean ± SD, and significance was assessed using Mann–Whitney test.