Researchers observed a decrease in the fecal microbial diversity in horses with EMS compared to metabolically normal horses. | Photo: iStock

In a recent study led by Melody de Laat, PhD, from Queensland University of Technology, in Australia, researchers sought to investigate three things:

• The tissue distribution of equine glucose-dependent insulinotropic polypeptide receptors (eGIPR)—receptors found mainly in gut that, when in the presence of glucose molecules, signals an increase in insulin secretion;
• If a GIP antagonist could block eGIPR;
• If a relationship exists between GIP concentration and obesity.

First, the researchers obtained pancreas samples from five healthy mixed-breed horses; they also gathered heart, kidney, lamellae, tongue, skeletal muscle, and duodenum (a part of the small intestine) samples from four healthy horses post-mortem in a previous study.

The team extracted tissue RNA from each sample and produced and sequenced a complementary DNA sample. This allowed them to determine specific gene expression in the various tissues. They confirmed eGIP gene expression in the heart, liver, pancreas, kidney, and duodenum; found very small amounts of eGIP expression in the lamellae and tongue; and observed no evidence of eGIP gene expression in the skeletal muscle