Continuous digital hypothermia prevents lamellar failure in the euglycaemic hyperinsulinaemic clamp model of equine laminitis.

BACKGROUND Continuous digital hypothermia can prevent the development and progression of laminitis associated with sepsis but its effects on laminitis due to hyperinsulinaemia are unknown. OBJECTIVES To determine the effects of continuous digital hypothermia on laminitis development in the euglycaemic hyperinsulinaemic clamp model. STUDY DESIGN Randomised, controlled (within subject), blinded, experiment. METHODS Eight clinically normal Standardbred horses underwent laminitis induction using the euglycaemic hyperinsulinaemic clamp model (EHC). At initiation of the EHC, one forelimb was continuously cooled (ICE), with the other maintained at ambient temperature (AMB). Dorsal lamellar sections (proximal, middle, distal) were harvested 48 h after initiation of the EHC and were analysed using histological scoring (0-3) and histomorphometry. Cellular proliferation was quantified by counting epidermal cell nuclei staining positive with an immunohistochemical proliferation marker (TPX2). RESULTS Severe elongation and disruption of SEL with dermo-epidermal separation (score of 3) was observed in all AMB feet at one or more section locations, but was not observed in any ICE sections. Overall 92% of the AMB sections received the most severe histological score (grade 3) and 8% were grade 2, whereas ICE sections were classified as either grade 1 (50%) or grade 2 (50%). Relative to AMB feet, ICE sections were 98% less likely to exhibit grades 2 or 3 (OR: 0.02, 95% CI 0.001, 0.365; P<0.01). Histomorphometry measurements of total and nonkeratinised primary epidermal lamellar length were significantly increased (P<0.01) in AMB limbs compared with ICE. TPX2 positive cell counts were significantly increased (P<0.01) in AMB limbs compared with ICE. MAIN LIMITATIONS Continuous digital hypothermia was initiated before recognition of laminitis and therefore the clinical applicability requires further investigation. CONCLUSIONS Continuous digital hypothermia reduced the severity of laminitis in the EHC model and prevented histological lesions compatible with lamellar structural failure.

[1]  M. Sillence,et al.  Characterization of insulin and IGF-1 receptor binding in equine liver and lamellar tissue: implications for endocrinopathic laminitis. , 2019, Domestic animal endocrinology.

[2]  K. Refsal,et al.  Association between hyperinsulinaemia and laminitis severity at the time of pituitary pars intermedia dysfunction diagnosis , 2018, Equine veterinary journal.

[3]  S. Eades,et al.  Ex vivo effects of insulin on the structural integrity of equine digital lamellae , 2019, Equine veterinary journal.

[4]  A. V. van Eps,et al.  Effect of Continuous Digital Hypothermia on Lamellar Inflammatory Signaling When Applied at a Clinically‐Relevant Timepoint in the Oligofructose Laminitis Model , 2017, Journal of veterinary internal medicine.

[5]  L. J. McCutcheon,et al.  Lamellar events related to insulin‐like growth factor‐1 receptor signalling in two models relevant to endocrinopathic laminitis , 2017, Equine veterinary journal.

[6]  N. Karikoski,et al.  Lamellar pathology in horses with pituitary pars intermedia dysfunction. , 2016, Equine Veterinary Journal.

[7]  N. Karikoski,et al.  Pathology of Natural Cases of Equine Endocrinopathic Laminitis Associated With Hyperinsulinemia , 2015, Veterinary pathology.

[8]  Xin-cheng Liu,et al.  TPX2 Level Correlates with Hepatocellular Carcinoma Cell Proliferation, Apoptosis, and EMT , 2015, Digestive Diseases and Sciences.

[9]  P. Savagner.  Epithelial-mesenchymal transitions: from cell plasticity to concept elasticity. , 2015, Current topics in developmental biology.

[10]  A. V. van Eps,et al.  Continuous digital hypothermia initiated after the onset of lameness prevents lamellar failure in the oligofructose laminitis model. , 2014, Equine veterinary journal.

[11]  J. Hauptman,et al.  Prophylactic digital cryotherapy is associated with decreased incidence of laminitis in horses diagnosed with colitis. , 2014, Equine veterinary journal.

[12]  L. J. McCutcheon,et al.  Effect of Dietary Nonstructural Carbohydrate Content on Activation of 5′‐Adenosine Monophosphate‐Activated Protein Kinase in Liver, Skeletal Muscle, and Digital Laminae of Lean and Obese Ponies , 2014, Journal of veterinary internal medicine.

[13]  Ricardo Garcia,et al.  The softening of human bladder cancer cells happens at an early stage of the malignancy process , 2014, Beilstein journal of nanotechnology.

[14]  N. Karikoski,et al.  Morphological and cellular changes in secondary epidermal laminae of horses with insulin-induced laminitis. , 2014, American journal of veterinary research.

[15]  Xinxiang Li,et al.  TPX2 is a novel prognostic marker for the growth and metastasis of colon cancer , 2013, Journal of Translational Medicine.

[16]  A. P. Kolychev,et al.  Differences in time course of internalization of receptors of insulin and insulin-like growth factor (IGF-1) in isolated rat hepatocytes , 2013, Journal of Evolutionary Biochemistry and Physiology.

[17]  T. Licka,et al.  Hyperinsulinaemia increases vascular resistance and endothelin-1 expression in the equine digit. , 2013, Equine veterinary journal.

[18]  C. Pollitt,et al.  A potential role for lamellar insulin-like growth factor-1 receptor in the pathogenesis of hyperinsulinaemic laminitis. , 2013, Veterinary journal.

[19]  L. J. McCutcheon,et al.  Distribution of insulin receptor and insulin-like growth factor-1 receptor in the digital laminae of mixed-breed ponies: an immunohistochemical study. , 2013, Equine veterinary journal.

[20]  C. Pollitt,et al.  Histological and morphometric lesions in the pre-clinical, developmental phase of insulin-induced laminitis in Standardbred horses. , 2013, Veterinary journal.

[21]  A. V. van Eps,et al.  Digital hypothermia inhibits early lamellar inflammatory signalling in the oligofructose laminitis model. , 2012, Equine veterinary journal.

[22]  C. Pollitt,et al.  Lamellar leukocyte infiltration and involvement of IL-6 during oligofructose-induced equine laminitis development. , 2011, Veterinary immunology and immunopathology.

[23]  A. V. van Eps,et al.  Equine laminitis: comparative histopathology 48 hours after experimental induction with insulin or alimentary oligofructose in standardbred horses. , 2011, Journal of comparative pathology.

[24]  N. Karikoski,et al.  The prevalence of endocrinopathic laminitis among horses presented for laminitis at a first-opinion/referral equine hospital. , 2011, Domestic animal endocrinology.

[25]  D. Beiser,et al.  Abstract 2: Therapeutic Hypothermia Cardioprotection During Cardiac Arrest Inhibits mTOR Kinase Signaling , 2010 .

[26]  R. Geor.  Current concepts on the pathophysiology of pasture-associated laminitis. , 2010, The Veterinary clinics of North America. Equine practice.

[27]  T. Vanden Hoek,et al.  Therapeutic hypothermia cardioprotection via Akt- and nitric oxide-mediated attenuation of mitochondrial oxidants. , 2010, American journal of physiology. Heart and circulatory physiology.

[28]  C. Pollitt,et al.  Equine laminitis: induced by 48 h hyperinsulinaemia in Standardbred horses. , 2010, Equine veterinary journal.

[29]  S. Bailey,et al.  Proliferative Effects of Insulin on Equine Lamellar Epithelial Cells Mediated By the IGF-1 Receptor , 2010 .

[30]  A. V. van Eps,et al.  Equine laminitis model: cryotherapy reduces the severity of lesions evaluated seven days after induction with oligofructose. , 2009, Equine veterinary journal.

[31]  C. Pollitt,et al.  Equine laminitis: ultrastructural lesions detected in ponies following hyperinsulinaemia. , 2009, Equine veterinary journal.

[32]  R. Geor,et al.  Metabolic syndrome-From human organ disease to laminar failure in equids. , 2009, Veterinary immunology and immunopathology.

[33]  L. Douglass,et al.  Prediction of incipient pasture-associated laminitis from hyperinsulinaemia, hyperleptinaemia and generalised and localised obesity in a cohort of ponies. , 2009, Equine veterinary journal.

[34]  C. Pollitt,et al.  Induction of laminitis by prolonged hyperinsulinaemia in clinically normal ponies. , 2007, Veterinary journal.

[35]  E. Armstrong,et al.  Differential binding and internalization of insulin-like growth factor (IGF)-I in cultured human trophoblast and JEG-3 cells: possible modulatory effect of IGF binding proteins (BP) , 1995, Endocrine.

[36]  A. V. van Eps,et al.  Lamellar pro-inflammatory cytokine expression patterns in laminitis at the developmental stage and at the onset of lameness: innate vs. adaptive immune response. , 2007, Equine veterinary journal.

[37]  A. V. van Eps,et al.  Equine laminitis induced with oligofructose. , 2010, Equine veterinary journal.

[38]  R. Geor,et al.  Insulin resistance in equids: possible role in laminitis. , 2006, The Journal of nutrition.

[39]  A. V. van Eps,et al.  Equine laminitis: cryotherapy reduces the severity of the acute lesion , 2010 .

[40]  Eric Karsenti,et al.  Tpx2, a Novel Xenopus Map Involved in Spindle Pole Organization , 2000, The Journal of cell biology.

[41]  C. Pollitt.  Basement membrane pathology: a feature of acute equine laminitis. , 1996, Equine veterinary journal.