Figure 3.

RXRα^adL−/− mice are resistant to obesity and are impaired in preadipocyte differentiation. (A) RXRα^adL−/− mice are resistant to HFD- and MSG-induced obesity. Total body weight of CT and RXRα^adL−/− (KO) mice under RD (a and b), under HFD (a) and after MSG treatment (b) was measured weekly. The number of animals monitored in each group was 10–15 males. Values are expressed as the mean ± SEM. (B) Reduced adipose tissue weight in RXRα^adL−/− mice under HFD or after MSG treatment compared with CT mice. Inguinal (ING), interscapular (INT), and retroperitoneal (RET) WAT weight was determined in 6-month-old CT and RXRα^adL−/− (KO) mice, fed with RD or HFD and after MSG treatment. Each group was composed of 5–7 males. Values are expressed as the mean ± SEM. (C) Impaired adipogenesis in RXRα^adL−/− mice. Cryosections of s.c. inguinal WAT from 6-month-old CT (a, c, and e) and RXRα^adL−/− (b, d, and f) mice, under RD (a and b), HFD (c and d), and after MSG treatment (e and f) were stained with hematoxylin and eosin. (Scale bar, 160 μm.) The areas of at least 400 cells per sample were determined with the NSURFX software (J. L. Vonesch, Institut de Génétique et de Biologie Moléculaire et Cellulaire Illkirch). The distribution of the cell size is shown in the corresponding graphs to the right. Arrows point to small adipocytes and preadipocytes or poorly differentiated adipocytes in e and f, respectively.