Whole Genome Functional Analysis of Laminar Tissue From Horses With Laminitis Induced by Prolonged Euglycemic-Hyperinsulinemic Clamp

Abstract

s Vol 30, No 2 (2010) 107 CHO administration or upon reaching Obel grade 3 lameness whichever occurred first. Horses in the treatment group received 8.5 mg/kg PTX in 1 L saline IV over 30 minutes beginning 12 hours prior to CHO administration, then every 12 hours thereafter until the completion of the study. MMP activity in the digital plasma will be evaluated using gelatin zymography. PRELIMINARY RESULTS All control horses (5/5) developed Obel grade 3 lameness, four of them within 32 hours post-CHO. However, only one PTX horse reached Obel grade 3. Of the remaining four PTX horses, two never became lame, one reached Obel grade 2 and then returned to almost complete soundness by 60 hours, and one fluctuated between Obel grades 1 and 2 during the entire study. MMP analysis is being performed at this time. DISCUSSION The horses appear to have responded favorably to PTX treatment with significantly decreased lameness. This response to PTX could result from 1) MMP inhibition, 2) anti-inflammatory effects of PTX, or 3) individual response to CHO. CLINICAL RELEVANCE If future data confirms our preliminary findings, PTX could be used as a preventative/treatment for cases of laminitis associated with carbohydrate overload. CONCLUSION PTX appears to decrease lameness associated with CHOinduced laminitis. Isolation of Equine Hoof Epidermal Cells for in Vitro Studies Hannah Galantino-Homer, Susan Megee, and Makoto Senoo, Laminitis Institute, Department of Clinical Studies/New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA TAKE HOME MESSAGE We present a method for aseptic retrieval of equine hoof epidermal cells. INTRODUCTION Disruption of basal epidermal cell-basement membrane adhesion is a key event during the developmental and acute phases of laminitis and disorganized proliferation of basal cells may contribute to the pathology of chronic laminitis. The isolation of these cells would facilitate in vitro studies of normal and disrupted basal cell-extracellular matrix adhesion and proliferation and could provide basal epidermal progenitor cells (BEPCs) for autografting following hoof wall resection. MATERIALS AND METHODS Aseptic surgical techniques are used to remove a 5 cm by 4 cm section of the dorsal hoof wall of equine cadavers up to 3 hr following euthanasia. Coronary and lamellar epidermal tissue and underlying dermal tissue are dissected by scalpel and washed in DPBS containing antibiotic/antimycotic and held in DMEM, 10% Fetal Calf Sera and antibiotic/antimycotic. Mechanical disruption by dicing, scraping, and electric homogenizer in combination with enzymatic digestion is used to generate a single cell suspension of mixed epidermal and dermal cells that are then frozen or used immediately for in vitro studies. RESULTS Mixed cells and selective culture have been used successfully in a preliminary experiment to generate BEPC holoclones. Non-selective in vitro culture of mixed cells results in non-uniform cell proliferation and differentiation. DISCUSSION AND CLINICAL RELEVANCE Selection of BEPCs is essential for repeatable culture of uniform populations of basal cells for laminitis pathophysiology studies as well as for successful therapeutic epidermal tissue regeneration. CONCLUSION Equine hoof BEPC selective culture from isolated mixed epidermal and dermal cells is currently under development. Chemical and Biological Properties of Aqueous Black Walnut Extracts That Contribute to the Pathogenesis of Laminitis D.J. Hurley, J.N. Moore, K.A. Hurley, L.J. Berghaus, K.L. Galland, and R.S.K. Majerle, Food Animal Health and Management Program, Department of Population Health, College of Veterinary Medicine, the University of Georgia, Athens, GA, Department of Large Animal Medicine, College of Veterinary Medicine, the University of Georgia, Athens, GA, Department of Chemistry, Hamline University, St. Paul, MN