IN-VITRO LIPID-SYNTHESIS IN HUMAN ADIPOSE-TISSUE FROM 3 ABDOMINAL SITES

The association between abdominal deposition of adipose tissue and mor bidities accompanying obesity may be related to high rates of free fat ty acid release from enlarged intra-abdominal stores. To investigate c ellular mechanisms that might contribute to enlargement of intra-abdom inal adipocytes, lipolysis, triacylglycerol (TG), and diacylglycerol ( DG) synthesis from [C-14] glucose was measured in abdominal subcutaneo us, omental, and mesenteric adipose tissue from severely obese women a nd men. Subcutaneous adipose tissue from women showed the highest rate s of TG synthesis compared with the intra-abdominal site, or any site in men. Isoproterenol stimulated TG synthesis more in intra-abdominal than subcutaneous adipose tissue. In the basal state, intra-abdominal adipose tissue from both men and women showed rates of [C-14]DG accumu lation approximately 50% total [C-14]acylglyceride accumulation, where as, in subcutaneous adipose tissue, [C-14]DG accumulation was approxim ately 25% of total. Basal lipolysis was lower in intra-abdominal than subcutaneous adipocytes. Stimulation of lipolysis reduced [C-14]DG acc umulation more in intra-abdominal than subcutaneous adipose tissue. Lo w rates of acylglyceride synthesis in intra-abdominal adipocytes may p revent accumulation of large intra-abdominal fat stores in women.