Ketone body utilization is regulated by male-specific factors in rat subcutaneous adipocytes.

BACKGROUND

Acetoacetyl-CoA synthetase (AACS) is the enzyme responsible for the utilization of ketone bodies for the synthesis of cholesterol and fatty acids and the gene is highly expressed only in the male subcutaneous white adipose tissue (WAT).

OBJECT

This study is to elucidate how AACS is involved in sex-dependent metabolic differences in adipose tissues. To answer this question, we examined the effect of castration on AACS mRNA expression in rat WAT.

RESULT

Castration did not affect any changes in the level of serum ketone bodies, but it significantly decreased AACS gene expression in subcutaneous WAT. In contrast, expression of the other ketone body utilizing enzyme, succinyl-CoA: 3-oxoacid CoA-transferase (SCOT), did not change. Moreover, the AACS gene was highly expressed in larger-sized adipocytes obtained from rat subcutaneous WAT, and was up-regulated by testosterone in differentiated adipocytes.

CONCLUSION

Our results suggest that AACS plays male-specific metabolic roles in the regulation of ketone body-utilization for lipogenesis and that sex-specific ketone body-utilization is restricted in subcutaneous WAT.