Direct free fatty acid storage in different sized adipocytes from the same depot.
Bottom Line: However, FFA storage rates were significantly (two to four times) greater per cell in large than small cells (P < 0.005).In summary, relative to lipid content, FFA storage rates are not different in large and small adipocytes, however, large cells have greater storage rates per cell.This suggests that the processes of FFA release and storage are taking place simultaneously in adipocytes.
Affiliation: Division of Endocrinology, Department of Medicine, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905, USA.Show MeSH
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Mentions: When suspended in an aqueous solution, larger adipocytes float to the surface faster than small adipocytes (6). Using this approach we separated three populations of different size cells. Briefly, the adipocyte mixture and 40 ml HEPES were placed in a 250 cc separation funnel, gently mixed, and allowed to float for 50 seconds, at which time the lower 35 ml was drained from the separation funnel into a 50 ml Falcon tube to collect small cell fraction. We replaced 35 ml of HEPES buffer to the funnel and repeated this same procedure step in an effort to collect the maximum number of the smallest cells. To obtain the medium size cell fraction, we repeated the addition of 35 ml of HEPES, gently mixed and used a 35 second floatation time. The final portion that contained the large cell size fraction was then drained from the funnel and collected in a third 50 ml Falcon tube. To retrieve any remaining cells, the funnel was rinsed with HEPES solution, which we collected and combined with the large cell fraction. All tubes were briefly centrifuged at 300g, and a small aliquot of the cell suspension (100-200 μl) was removed from the original whole and each fraction for cell sizing with the remainder set aside for lipid extraction. A typical set of photomicrographs following this procedure are shown in Figure 1.
Affiliation: Division of Endocrinology, Department of Medicine, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905, USA.