Differences in adipocytokines and fatty acid composition between two adipocyte fractions of small and large cells in high-fat diet-induced obese mice.

Objective: This study was conducted to compare the differences in adipocytokines and fatty acid composition between two fraction sizes of small and large cells from subcutaneous and visceral fat of mice receiving a high-fat diet (HFD).
Methods: Body weight, blood glucose and cholesterol levels, and adipocyte diameter distribution were examined. Total adipocyte fractions could be separated into the small-cell fraction (SCF) and the large-cell fraction (LCF). Adipocytokine expression, fatty acid composition and stearoyl-CoA desaturase (SCD) expression were compared between SCF and LCF.
Results: In HFD mice, body weight, glucose and cholesterol levels were significantly higher than in NCD mice. The adipocyte diameter of HFD mice continuously increased throughout the feeding period regardless of the fat depot. The expression of adipocytokine genes such as angiotensinogen, plasminogen activator inhibitor-1, adipsin, leptin, TNF-alpha and adiponectin was higher in LCF than SCF. The ratio of stearic acid to the total fatty acid content was lower in SCF than LCF, whereas oleic acid composition was higher in LCF. SCD expression was higher in LCF than SCF.
Conclusion: Our results indicate that large adipocytes strongly express adipocytokine genes and show high oleic acid composition via SCD upregulation. Based on these findings, the differences in fatty acid composition between adipocyte sizes may be related to adipocytokine expression.
(Copyright 2009 S. Karger AG, Basel.)