The cellular and metabolic organization of ovine subcutaneous adipose tissue

Abstract

The cellular organization and lipogenic capacity ([14C]acetate incorporation per l06 cells) of sections, parallel to the skin, of subcutaneous adipose tissue from the rump, shoulder and brisket regions of fat sheep were studied. Adipocytes from the brisket (134 ¦m in mean diameter; 1.35 nl in mean volume) were smaller than those from the shoulder (213 ¦m; 4.77 nl) or rump (202 ¦m; 4.69 nl). Furthermore, cells from the brisket incorporated significantly less [I4C]acetate than those from either the shoulder or rump, which were not significantly different in lipogenic capacity. The frequency distributions of diameters of cells from the rump and shoulder were predominantly normal, but those of brisket cells were positively skewed. Adipocytes were larger and lipogenesis was greater in sections closer to the skin than in sections closer to the muscle for each region. This gradient of cell size and lipogenic capacity indicates that ovine subcutaneous adipose tissue is not homogeneous but is organized in structure and metabolism.