Adipobiology (The Study of Fat in the Body): An Emerging Field

What exactly does stored fat do to a horse’s body? It wreaks serious havoc on at least 11 vital body functions. Nat Messer, DVM, Dipl. ABVP, an associate professor of equine medicine and surgery at the University of Missouri (UM), presented a compelling discussion of the relatively new field of adipobiology–the study of fat and its causes and effects. He discussed a paper submitted by Philip Johnson, BVSc(Hons), MS, Dipl. ACVIM, Dipl. ECEIM, MRCVS, professor of veterinary medicine and surgery at UM.

Excess body fat (both subcutaneous fat, such as the squishy stuff around a horse’s tailhead, and visceral fat that accumulates near various internal organs) isn’t just an unsightly way to store extra calories. Researchers are learning that fat–or adipose tissue as it’s scientifically called–is much more active biochemically in many species than was previously thought (particularly visceral fat), noted Johnson in his paper. Fat produces more than 100 substances (collectively called adipokines or adipocytokines) that can affect:

  • Lipid and glucose homeostasis (normal fat and glucose balance in the body);
  • Inflammation;
  • Hemostasis (control of bleeding);
  • Osteogenesis (bone production);
  • Hematopoiesis (formation and development of blood cells);
  • Complement activities (complement is a sequence of proteins in the blood that work to help the animal respond to inflammatory and infectious challenges);
  • Reproduction;
  • Angiogenesis (development of blood vessels in tissue);
  • Blood pressure; and
  • Feeding behavior.

In horses, adipokine-mediated alteration of