Effect of various dietary fats on rat adipose tissue gene expression. Rats were fed, one of the following isocaloric diets containing identical amounts of all dietary constituents except the type of dietary fat: trans fatty acid diet (TFA diet), saturated fatty acid diet (SFA diet), polyunsaturated fatty acid diet (PUFA diet). After 12 months of feeding, gene expression was analyzed in retroperitoneal adipose tissue by RT-PCR. (A) Representative photo of 11β-HSD1 PCR product, stained by ethidium bromide. (B) Representative photo of C/EBP-α PCR product, stained by ethidium bromide. (C) Representative photo of β-actin, PCR product (internal control), stained by ethidium bromide. (D) Relative 11β-HSD1, C/EBP-α and LXR-α mRNA expression was measured in relation to β-actin mRNA levels. Relative percentage gene expression of candidate gene in TFA- or SFA -fed rat RPWAT was calculated taking the relative gene expression observed in PUFA-fed rat RPWAT as 100. Values are mean ± SD, n = 3, (*, P < 0.05).