Figure 2.

Full activation of insulin-stimulated glucose uptake in adipocytes requires ATP release by Panx1 channels. (A) Blockade of Pannexin-1 channels with carbenoxolone (100 μM, CBX) or probenecid (1 mM, Prob) significantly decreases insulin-stimulated ³H-glucose uptake in 3T3L1-adipocytes. Data are expressed as mean ± s.e.m. *p < 0.001 by 2 way ANOVA with Tukey's multiple comparisons test. (B) Insulin-stimulated glucose uptake is significantly decreased in adipocytes isolated from perigonadal adipose tissue of adipocyte-specific Pannexin-1 null mice. Addition of exogenous ATP (50 μM) restores insulin-stimulated ¹⁴C-glucose uptake in adipocytes isolated from Panx1 null mice. Data are expressed as mean ± s.e.m. *p < 0.003 by 1 way ANOVA with Tukey's multiple comparisons test. (C) In vivo [³H] 2-deoxy-d-glucose uptake was assessed in perigonadal white adipose tissue (WAT) and gastrocnemius muscle (MUS) in age-matched, male, chow fed WT and AdipPanxKO littermates (n = 6). Data are presented as mean ± s.e.m. *p < 0.05 by paired t-test. Dotted line indicates the 20% decrease in glucose uptake in WAT in AdipPanxKO mice compared to WT.