Effects of short term high fat diet on obesity and perivascular adipose structure and function in mice : role of aldose reductase, and aldehyde metabolizing enzyme

This study was undertaken to determine the effects of high fat diet and aldose reductase deficiency on the structure and function of murine perivascular adipose tissue. Wild type (WT) (C57 bl/6) and aldose reductase knockout (AR-null) mice were aged to 8 or 18 weeks on a normal chow diet then some were switched to a high fat diet for 4 weeks while others remained on the control diet for the same amount of time. Following 4 weeks, mice were euthanized PVAT was analyzed. High fat feeding significantly increased body fat percentage in both age groups of mice and the area of PVAT present around distal thoracic aorta sections also increased. Additionally, WT and AR-null mice appeared to exhibit an increase in the area of white adipocyte clusters present in PVAT, although the results were not significant. When examining the area of white adipocytes present in PVAT, HF feeding significantly increased area of adipocytes throughout PVAT in WT, 22-week old mice and a significant increase in VAT and overall PVAT, but not DAT in AR-null mice. To examine the functional properties of PVAT, sections of aorta with intact and removed PVAT were measured for contraction and relaxation properties. In WT mice, HF feeding resulted in endothelial dysfunction, seen as a reduced relaxation response to acetylcholine. The presence of intact PVAT reversed the observed dysfunction. Collectively, these data suggest that PVAT adiposity is increased similar to overall adiposity with high fat feeding and that this change is structure may contribute to the functional changes also observed with high fat feeding.