title: Adipose tissue fatty acid storage factors: effects of depot, sex and fat cell size.
abstract: OBJECTIVE
  Patterns of postabsorptive adipose tissue fatty acid storage correlate with sex-specific body fat distribution. Some proteins and enzymes participating in this pathway include CD36 (facilitated transport), acyl-CoA synthetase (ACS; the first step in fat metabolism) and diacylglycerol acetyltransferase (DGAT; the final step of triglyceride synthesis). Our aim was to better define CD36, ACS and DGAT in relation to sex, subcutaneous fat depots and adipocyte size.
  
  
  METHODS
  Data were collected from studies conducted at Mayo Clinic between 2004 and 2012. Abdominal and femoral subcutaneous fat biopsy samples must have been collected in the postabsorptive state from healthy males and premenopausal females. Body composition was measured with dual-energy X-ray absorptiometry and abdominal computerized tomography scans. Adipocyte size (microscopy), CD36 protein content (enzyme-linked immunosorbent assay) and ACS and DGAT enzyme activities were measured. Data are presented as medians and 25th, 75th quartiles.
  
  
  RESULTS
  Males (n=60) and females (n=78) did not differ by age (37; 28, 46 years), body mass index (28.4; 24.6, 32.1 kg m(-)(2)) or abdominal (0.60; 0.45, 0.83 μg lipid per cell) and femoral adipocyte size (0.76; 0.60, 0.94 μg lipid per cell). Femoral ACS and DGAT were greater in females than males when expressed per mg lipid (ACS: 73 vs. 55 pmol/mg lipid/min; DGAT: 5.5 vs. 4.0 pmol/mg lipid/min; P<0.0001 for both) and per 1000 adipocytes (ACS: 59 vs. 39 pmol per min per 1000 adipocytes; DGAT: 4.3 vs 3.1 pmol per min per 1000 adipocytes; P⩽0.0003 for both). There were no differences in abdominal fat storage factors between sexes. ACS and DGAT decreased as a function of adipocyte size (P<0.0001 for both). The decrease in ACS was greater in males and abdominal subcutaneous fat. There were no sex differences in CD36 in either fat depot, nor did it vary across adipocyte size.
  
  
  CONCLUSIONS
  Facilitated transport of fatty acids by CD36 under postabsorptive conditions would not be different in those with large vs small adipocytes in either depot of both sexes. However, intracellular trafficking of fatty acids to triglyceride storage by ACS and DGAT may be less efficient in larger adipocytes.
authors: Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA.
authors: K C
authors: KC
authors: Hames
authors: Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA.
authors: C
authors: C
authors: Koutsari
authors: Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA.
authors: S
authors: S
authors: Santosa
authors: Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA.
authors: N C
authors: NC
authors: Bush
authors: Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA.
authors: M D
authors: MD
authors: Jensen
mesh_terms: D017667:Adipocytes / Q000473:pathology*; D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D050218:Body Fat Distribution; D018955:CD36 Antigens / Q000378:metabolism*; D048429:Cell Size; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D050151:Subcutaneous Fat / Q000378:metabolism / Q000473:pathology*; D014280:Triglycerides / Q000378:metabolism
chemical_list: D018955:CD36 Antigens; D005227:Fatty Acids; D014280:Triglycerides
references: Curr Opin Clin Nutr Metab Care. 2001 Nov;4(6):499-502
references: 11706283
references: Am J Physiol Endocrinol Metab. 2012 Jun 15;302(12):E1599-604
references: 22510710
references: Diabetes. 2013 Mar;62(3):775-82
references: 23209188
references: Diabetes. 2014 Nov;63(11):3606-14
references: 24917573
references: J Lipid Res. 2003 Sep;44(9):1795-801
references: 12777477
references: J Biol Chem. 2003 Oct 31;278(44):43008-13
references: 12937175
references: Am J Clin Nutr. 1995 Feb;61(2):274-8
references: 7840063
references: Prog Lipid Res. 1995;34(1):53-70
references: 7644553
references: J Biol Chem. 1999 Jul 2;274(27):19055-62
references: 10383407
references: Int J Obes (Lond). 2006 Jun;30(6):877-83
references: 16418758
references: Diabetes. 2007 May;56(5):1369-75
references: 17287467
references: Am J Clin Nutr. 2008 Jan;87(1):56-63
references: 18175737
references: Int J Obes (Lond). 2008 Feb;32(2):283-91
references: 17726433
references: Diabetologia. 2009 May;52(5):882-90
references: 19252892
references: Obesity (Silver Spring). 2009 Jun;17(6):1129-34
references: 19197254
references: Metabolism. 2009 Nov;58(11):1564-71
references: 19595383
references: Obesity (Silver Spring). 2010 Feb;18(2):261-5
references: 19696757
references: Proc Natl Acad Sci U S A. 2010 Oct 19;107(42):18226-31
references: 20921416
references: J Lipid Res. 2011 Feb;52(2):408-15
references: 21115967
references: Am J Physiol Endocrinol Metab. 2011 Jul;301(1):E105-12
references: 21505146
references: Diabetes. 2011 Aug;60(8):2032-40
references: 21659500
references: Diabetes. 2012 Feb;61(2):329-38
references: 22228715
references: PLoS One. 2012;7(2):e31473
references: 22363653
references: Nat Rev Genet. 2012 Apr;13(4):227-32
references: 22411467