Differential effects of obesity on acetoacetyl‐CoA synthetase gene in rat adipose tissues

In order to investigate the physiological role of the ketone body‐utilizing enzyme acetoacetyl‐CoA synthetase (AACS) in obesity‐induced metabolic derangements, we examined the mRNA levels of AACS and other lipogenic enzymes in white adipose tissues (WAT) in the different types of obesity, genetic (Zucker fatty) and high‐fat diet (HFD)‐induced obesity. Plasma ketone body levels and gene expression levels of AACS and acetyl‐CoA carboxylase‐2 (ACC‐2) in WAT were lower in Zucker fatty rats than in lean rats. On the contrary, in HFD‐induced obese rats, these levels were increased. Moreover, AACS mRNA expression was affected only in subcutaneous WAT by each type of obesity. Our data suggest that AACS mRNA expression is related to obesity‐induced alteration of plasma ketone body levels, and that AACS in subcutaneous WAT plays an important role in the regulation of lipogenesis and ketone body utilization in various obese conditions.