Figure 2.

Acid sphingomyelinase deficiency protects from diet-induced adipocyte hypertrophy. (A) Adipose tissue from acid sphingomyelinase–deficient (Smpd^−/−) mice and C57BL/6 mice (wild-type, WT) fed either a standard diet (SD) or a Western diet (WD) for 6 weeks was sectioned and stained with hematoxylin and eosin (H&E). WD consumption led to hypertrophy of adipocytes in WT mice but not in Smpd^−/− mice. (B) Mean adipocyte diameter was significantly larger in WD-fed WT mice than in WD-fed Smpd^−/− mice. (C) Although SD-fed Smpd^−/− mice exhibited higher serum concentrations of free fatty acids (FFAs), no statistically significant differences were observed between the WD-fed groups because of higher FFA concentrations in WT mice. (D) Serum adiponectin concentrations were lower in WD mice than in SD mice, irrespective of genotype. (E) WD-fed WT mice exhibited substantial hyperleptinemia; this condition did not occur in Smpd^−/− mice.