Sex hormones are likely to be involved in sex differences in adipose tissue 
distribution. To test whether estrogen regulates genes expressed in the adipose 
tissue in a site-specific manner, we studied the effect of exogenous estradiol 
on the gene expression in visceral and subcutaneous adipose tissues of male 
ob/ob mice. We screened genes expressed in a site- and sex-specific manner, and 
genes that were affected by exogenous estradiol by DNA chip analysis. They were 
verified by real-time PCR. Myosin heavy chain 2B (Myh4) and phosphoglycerate 
mutase muscle-specific subunit (Pgam) were expressed specifically in the 
subcutaneous adipose tissue, and uroplakin IIIb (UP3) was expressed specifically 
in the visceral adipose tissue. DEAD-box Y RNA helicase (DBY) and eukaryotic 
initiation factor 2 gamma Y (eIF2gamma Y) were expressed only in male adipose 
tissue. X-chromosome inactive specific transcript (Xist) was expressed only in 
female adipose tissue. When estradiol was subcutaneously administrated to male 
mice, the expression of monocyte-chemoattractant protein-1 (MCP-1) and androgen 
receptor (AR) genes was regulated in a site-specific manner. The difference in 
the amount of estrogen receptor did not account for the site-specific effect of 
estrogen. Our findings show that estrogen affects the expression of some 
adipocyte genes in a site-specific manner.