Figure 5.

Female HSD2^OB/OCY-tg mice maintained adipose tissue energy expenditure with aging. (a) Representative images of tyrosine hydroxylase (TH)-stained sections of BAT from young and aged wild-type and HSD2^OB/OCY-tg mice; scale bar = 50 μm. (b, c) Number of, and area covered by, sympathetic nerve endings in BAT. Data are shown as scatterplots, with mean values shown as columns. (d) Representative images of H&E stained gonadal adipose tissue, showing regions of beige adipocytes, from young and aged wild-type and HSD2^OB/OCY-tg mice. Insets show UCP1 staining; scale bar = 100 μm. (e) Multilocular adipocyte area in gonadal adipose tissue. (f) Proportion of samples showing presence of beige cells in gonadal adipose tissue (n = 6–8/group). (g) Number of TH-positive nerve terminals in gonadal adipose tissue (logarithmic scale). (h, i, j) Oxygen consumption rate (OCR), ATP turnover and proton leak measured ex vivo in gonadal adipose tissue from 3-, 6-, 12- and 18-month-old female wild-type and HSD2^OB/OCY-tg mice. (k) Proportion of samples showing presence of beige cells in inguinal adipose tissue (n = 6–8/group). (l) Oxygen consumption rate (OCR) measured ex vivo in inguinal adipose tissue of 3-, 6-, 12-, and 18-month-old female wild-type and HSD2^OB/OCY-tg mice. (m) Twenty-four-hour energy expenditure following injection with saline or CL-316,243 (5 μg/g lean body mass) in female wild-type and HSD2^OB/OCY-tg mice aged 3 and 18 months. Comparisons between groups were performed by two-way ANOVA (except (f) and (k), in which χ²-tests were used), and Tukey's post hoc tests were used for pairwise comparisons. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 and ∗∗∗∗p < 0.0001 for comparisons.