Lipogenic activity and brown fat content of human perirenal adipose tissue

The incorporation of 3H2O and/or 14C-glycerol into lipids and the specific activities of the enzymes acetyl CoA carboxylase and lipoprotein lipase were measured in the perirenal and subcutaneous adipose tissue of human subjects. The perirenal adipose tissue of younger subjects with higher brown adipocyte content had higher rates of lipogenesis and enzyme activities per gram tissue than the corresponding subcutaneous tissue. However, in individual specimens, the perirenal/subcutaneous ratios of all but one of the above parameters failed to show a correlation with the brown adipocyte content of the perirenal adipose tissue. One parameter, namely 3H2O incorporation into fatty acids per adipocyte, did relate to the brown adipocyte content of the perirenal adipose tissue in four normal-weight patients only.