Arachidonic acid and glucose uptake by freshly isolated human adipocytes.
Fatty acid (FA) and glucose transport into insulin-dependent cells are impaired in insulin resistance (IR; type 2 diabetes mellitus). Studies done on the effects of FAs on glucose uptake, and the influence of insulin on FA uptake by adipocytes, have yielded contradictory results. In this study, isolated human adipocytes were exposed to arachidonic acid (AA) and to insulin, and FA uptake as well as glucose uptake was measured. AA uptake into adipocyte membranes and nuclei was also investigated. Glucose uptake was inhibited by 57 +/- 8% after 30 min of exposure to arachidonate. AA was significantly taken up into adipocyte membranes (49.6 +/- 29% and 123 +/- 74%) at 20 and 30 min of exposure, respectively, and into nuclei (147.6 +/- 19.2%) after 30 min. Insulin stimulated AA uptake (24.1 +/- 14.1%) at 30 min by adipocytes from a non-obese subject, while inhibiting it (16.6 +/- 12%) in adipocytes from an obese subject. These results suggest that: (1) AA inhibits glucose uptake by adipocytes exposed over a short period, probably by a membrane-associated mechanism, (2) insulin-dependent AA uptake is dependent on the body mass index (BMI) of the donor and the insulin sensitivity of their adipocytes.
Malipa
Ana C A
AC
Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, South Africa.
Meintjes
Roy A
RA
Haag
Marianne
M
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016718:Arachidonic Acid / Q000493:pharmacokinetics*; D001692:Biological Transport / Q000187:drug effects; D015992:Body Mass Index; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000493:pharmacokinetics*; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance; D013997:Time Factors; D014018:Tissue Distribution
D007328:Insulin; D016718:Arachidonic Acid; D005947:Glucose