In vivo FABP4 secretion is blunted upon sympathetic nervous inhibition. A: Plasma corticosterone levels in 6 h fasted ATGLfl/fl and ATGLAdpKO mice (N = 5–7/group; Student’s t-test). B: Plasma FABP4 in ATGLfl/fl and ATGLAdpKO injected with 100 μl sterile PBS (N = 3–5/group; two-way ANOVA). C: Correlation of plasma FABP4 and plasma corticosterone levels in ATGLfl/fl and ATGLAdpKO mice (N = 20). D: Plasma FABP4, (E) NEFAs, and (F) insulin following administration of 20 mg/kg hexamethonium and 0.1 mg/kg CL-316,243 (N = 5–6/group; two-way ANOVA). Western blot and quantification of ATGL and FABP4 protein levels, normalized to total protein (Ponceau S stain), in (G) epididymal white adipose tissue (WAT) and (H) brown adipose tissue (BAT) from ATGLfl/fl and ATGLAdpKO housed at room temperature or 3 weeks at thermoneutrality (N = 4/group; one-way ANOVA). I: Plasma corticosterone levels in 6 h fasted ATGLfl/fl and ATGLAdpKO mice housed at room temperature or 2 week thermoneutrality and 15 min post ISO injection (10 mg/kg) (N = 6/group; two-way ANOVA). Plasma (J) FABP4, (K) NEFA, and (L) insulin following administration of ISO (N = 6/group; two-way ANOVA). All mouse experiments performed in 8- to 10-week-old male mice. Data are presented as mean ± SEM.