Abstract
Background/ObjectivesPatterns 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 synthetases (ACS; the first step in fat metabolism), and diacylglycerol acetyl-transferase (DGAT; the final step of triglyceride synthesis). Our goal was to better define CD36, ACS and DGAT in relation to sex, subcutaneous fat depots, and adipocyte size.Subjects/MethodsData was 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 DXA and abdominal CT scans. Adipocyte size (microscopy), CD36 protein content (ELISA), and ACS and DGAT enzyme activities were measured. Data are presented as medians; 25th:75th quartiles.ResultsMales (n=60) and females (n=78) did not differ by age (37;28:46 yr), BMI (28.4;24.6:32.1 kg/m2), or abdominal (0.60;0.45:0.83 μg/cell) and femoral adipocyte size (0.76;0.60:0.94 μg/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/1000adipocytes/min; DGAT: 4.3 vs. 3.1 pmol/1000adipocytes/min; 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.ConclusionsFacilitated 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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.