Figure 2.

ATGL in BAT Is Not Essential for Thermogenesis during Acute Cold

(A) ATGL immunoblot of BAT homogenates (n = 4; representative of at least two independent analyses).

(B) Ex vivo lipolysis in BAT under basal and isoproterenol (ISO)-stimulated conditions (n = 4).

(C) TG hydrolase activities in BAT infranatants in the absence or presence of ATGL inhibitor Atglistatin (ATGLi) from mice exposed to 5°C for 6 hr (n = 5).

(D) BAT weight (n = 11) and tissue gross morphology (inset).

(E) Histology of BAT. Scale bar, 100 μm.

(F) Body temperature in ad libitum-fed mice during acute cold exposure at 5°C (n ≥ 5).

(G) DNA content in brown adipocytes (adi) and stroma-vascular fraction (SVF; n = 3).

(H) UCP-1 immunoblot of isolated BAT mitochondria upon acute cold exposure.

(I) Oxygen consumption rates (OCRs) in BAT homogenates (hom) using pyruvate (pyr), glycerol-3-P (G3P) in the absence and presence of rotenone (G3P/R), and guanosine 5′-diphosphate (GDP). OCRs were calculated for whole BAT depots (n = 6).

Analyses were performed in male mice, except for (G), which used female mice, aged 9–11 weeks and 4 weeks upon tamoxifen administration. Data are presented as means ± SD. Statistical significance was evaluated by unpaired two-tailed Student’s t test or two-way ANOVA with Bonferroni post hoc tests. ^∗p < 0.05, ^∗∗p < 0.01, and ^∗∗∗p < 0.001 versus ATGL^flox/flox control and ^§p < 0.05 versus basal. See also Figure S2.