Relationships between Rodent White Adipose Fat Pads and Human White Adipose Fat Depots

Abstract

The objective of this review was to compare and contrast the physiological and metabolic profiles of rodent white adipose fat pads with white adipose fat depots in humans. Human fat distribution and its metabolic consequences have received extensive attention, but much of what has been tested in translational research has relied heavily on rodents. Unfortunately, the validity of using rodent fat pads as a model of human adiposity has received less attention. There is a surprisingly lack of studies demonstrating an analogous relationship between rodent and human adiposity on obesity-related comorbidities. Therefore, we aimed to compare known similarities and disparities in terms of white adipose tissue (WAT) development and distribution, sexual dimorphism, weight loss, adipokine secretion, and aging. While the literature supports the notion that many similarities exist between rodents and humans, notable differences emerge related to fat deposition and function of WAT. Thus, further research is warranted to more carefully define the strengths and limitations of rodent WAT as a model for humans, with a particular emphasis on comparable fat depots, such as mesenteric fat.

Keywords: fat depot; fat distribution; fat pads; humans; obesity; rodents.

Figure 1

(A) Distribution of fat depots in the human. The white adipose tissue (WAT) is found in subcutaneous adipose tissue (SAT) abdominally (a), gluteofemorally (g), and intramuscularly (h). WAT is also found in the visceral adipose tissue (VAT). The visceral depots are omental (b), mesenteric (c), retroperitoneal (d), gonadal (e), and pericardial (f). Brown adipose tissue is found supraclavicularly (i) and in the subscapular region (j). (B) Those fat depots linked to increased risk of developing obesity-related morbidities and mortality are colored in red (13).

Figure 2

Distribution of fat pads in the mouse. The fat is composed of two subcutaneous pads and several visceral pads. The main white adipose tissue (WAT) pads are the inguinal and epididymal, with the latter being the most frequent dissected pad. Brown adipose tissue (BAT) is distributed throughout the fat pads with the main BAT depot in the interscapular region (18).