Targeting the insulin-like growth factor 1 receptor may be an option for developing new drugs to prevent and treat the disease, according to a veterinary research team in Australia.

Veterinary researchers in Australia have identified a possible mechanistic link between high levels of insulin and equine laminitis.

The study, which investigated the effects of insulin on equine hoof lamellar cells in the laboratory, was conducted by the University of Melbourne Faculty of Veterinary and Agricultural Science, in conjunction with the Waltham Equine Studies Group, which underpins the science behind the Spillers brand.

The study has been published in Peer J.

Endocrine laminitis

High levels of the hormone insulin have been known for some time to cause acute endocrine laminitis.

The mechanism by which insulin – a metabolic hormone known best for its role clearing glucose from the blood stream – can cause effects in the foot leading to laminitis has been the subject of much debate in past years.

Hormones such as insulin must interact with a specific receptor on the surface of cells to produce their effects. What has confused researchers in the past is no insulin receptors appear to be on the hoof lamellar cells.

The researchers considered the close similarities between insulin and a growth factor hormone called insulin-like growth factor 1 (IGF-1).

Receptors for IGF-1 exist on the lamellar cells, and the researchers speculated high concentrations of insulin might be able to cross-stimulate these cells by activating the IGF-1 receptors.

Method

To investigate this possibility, PhD student Courtnay Baskerville, together with her supervisor Simon Bailey, developed a method for culturing lamellar epithelial cells in the laboratory and incubated them with increasing concentrations of insulin.

They found high concentrations of insulin stimulated the cells to proliferate. Furthermore, this effect could be prevented using an antibody that specifically blocks only the IGF-1 receptor.

Further work is ongoing to determine exactly how these cellular changes – induced by sustained high insulin concentrations – might cause laminitis. However, it seems targeting the IGF-1 receptor may be an option for developing new drugs to prevent and treat laminitis.