Figure 2.

Impaired physical capacity with cocaine challenge in the absence of K_ATP channels. (A) Kir6.2 knock out compromises physical endurance and impairs cardiac performance in chronic cocaine abuse. Under exercise stress testing, Kir6.2‐KO exhibited impaired endurance compared to matched cocaine‐challenged WT with decreased workload tolerance (25% less than at drug‐free state for Kir6.2‐KO vs. 27% above baseline for WT) and exercise duration (11% decrease from baseline for Kir6.2‐KO vs. no change for WT) after 20 days of cocaine administration. (B) Food consumption normalized to body weight was constant before (198.7 ± 9.4 mg/day/g vs. 224.5 ± 9.0 mg/day/g) and after (204.4 ± 12.4 mg/day/g vs. 210.1 ± 6.8 mg/ day/g) cocaine administration in WT vs. Kir6.2‐KO. (C) Both WT and Kir6.2‐KO animals experienced a reduction in body weight. However, body weight was indistinguishable between groups before (30 ± 0.8 g in WT vs. 28.1 ± 0.8 g in Kir6.2‐KO) and after (27.1 ± 0.9 g in WT vs. 25.5 ± 0.9 g in Kir6.2‐KO) the cocaine administration regimen. In each group, n= 5; *p < 0.05 when comparing each group to baseline drug‐free state. *p < 0.05 when comparing WT versus Kir6.2‐KO.