Direct Free Fatty Acid Uptake Into Human Adipocytes In Vivo

Direct Free Fatty Acid Uptake Into Human Adipocytes In Vivo

Shadid S, Koutsari C, Jensen M; 2007

Synopsis: This study tested whether direct uptake of circulating free fatty acids by fat cells occurs in vivo in overnight postabsorptive humans and, if so, whether there are regional differences in uptake between lean and obese women and men

Abstract: We sought to assess whether direct uptake of circulating free fatty acids (FFAs) by adipocytes occurs in vivo in overnight postabsorptive humans and, if so, whether there are regional differences in uptake between lean and obese women and men. We used bolus injections of radiolabeled FFA tracers followed by carefully timed adipose tissue biopsies. First, we validated a method to measure direct adipocyte FFA uptake and then quanti- tated this process using the modified methods in normal- weight postabsorptive men and women. We then used a continuous infusion of radiolabeled FFA to measure direct and indirect (VLDL) regional adipose tissue up- take in obese men and women. Direct FFA uptake was greater in women than men: 8.2 0.6 vs. 4.0 0.5% (P < 0.0001) of FFAs were taken up by subcutaneous adipose tissue, respectively. Abdominal subcutaneous fat took up FFAs more avidly than femoral fat in men, but this did not occur in women. Similar sex and regional difference were found to occur in obese women and men. Gene expression of fatty acid transporters was greater in abdominal than femoral fat in men (P < 0.05) but not in women (P 0.80). We observed sex- and site-specific recycling of circulating FFAs into subcutaneous fat. This is a novel FFA disposal pathway that may also play a role in the development or maintenance of body fat distribu- tion. Regional variations in facilitated fatty acid trans- port may contribute to this process. Diabetes 56:13691375, 2007.

APA Citation: Shadid, S., Koutsari, C., & Jensen, M. (2007). Direct Free Fatty Acid Uptake Into Human Adipocytes In Vivo: Relation to Body Fat Distribution. Diabetes, 56(5), 1369-1375. http://dx.doi.org/10.2337/db06-1680

AMA Citation: Shadid S, Koutsari C, Jensen M. Direct Free Fatty Acid Uptake Into Human Adipocytes In Vivo: Relation to Body Fat Distribution. Diabetes. 2007;56(5):1369-1375. doi:10.2337/db06-1680.