Abstracts | EQUINE
Ex vivo effects of insulin on the structural
integrity of equine digital lamellae
C. Sandow L. A. Fugler B. Leise L. Riggs W. T. Monroe N. Totaro J. Belknap S. Eades
First published: 14 May 2018
Background
Laminitis has a considerable impact on the equine
industry. Endocrinopathic laminitis is the most
common form and affected horses often have
hyperinsulinaemia due to an underlying metabolic
disorder.
Objectives
The aim of this study was to determine if insulin
weakens the structural integrity of digital lamellae
and to develop an ex vivo model for the study of
hyperinsulinaemia‐induced lamellar failure.
Study design
Ex vivo experiment.
Methods
Biomechanical testing was used to assess the
structural integrity of lamellar explants exposed
to either medium alone (control) or medium
supplemented with insulin. Lamellar explants
comprised of hoof wall, lamellar tissue and distal
phalanx were harvested from four adult horses with
no evidence of inflammatory disease or pre‐existing
disease of the digit. Following an equilibration
period, explants were incubated in medium or
medium supplemented with insulin (2.5 μg/ml) for
8 h prior to biomechanical testing to obtain load
(N), stress (MPa), elongation to failure (mm), and
Young's modulus (MPa) for each explant. Significant
differences were assessed using a mixed linear model
with horses as a random factor and control or insulin‐
treated group as a fixed factor.
Results
Lamellar explants incubated in medium
supplemented with insulin failed at significantly
lower load (P = 0.0001) and lower stress (P = 0.001)
and had greater elongation to failure (P = 0.02).
Main limitations
In addition to the ex vivo nature of the study,
location‐dependent variability in explant structural
integrity and variable diffusion of nutrients due to
explant size may have been limitations. However,
the study design attempted to account for these
limitations through random assignment of explants
to treatment groups independent of location and by
evaluating stress to failure.
Conclusions
Insulin weakens the structural integrity of equine
lamellar explants and an ex vivo model for evaluation
of hyperinsulinaemia‐induced lamellar failure was
established.
• Volume 20 Issue 3 | October 2018 •
https://doi.org/10.1111/evj.12964
11