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Acute Laminitis (acute + laminitis)
Selected AbstractsEquine laminitis: glucose deprivation and MMP activation induce dermo-epidermal separation in vitroEQUINE VETERINARY JOURNAL, Issue 3 2004K. R. French Summary Reasons for performing study: Acute laminitis is characterised by hoof lamellar dermal-epidermal separation at the basement membrane (BM) zone. Hoof lamellar explants cultured in vitro can also be made to separate at the basement membrane zone and investigating how this occurs may give insight into the poorly understood pathophysiology of laminitis. Objectives: To investigate why glucose deprivation and metalloproteinase (MMP) activation in cultured lamellar explants leads to dermo-epidermal separation. Methods: Explants, cultured without glucose or with the MMP activator p -amino-phenol-mercuric acetate (APMA), were subjected to tension and processed for transmission electron microscopy (TEM). Results: Without glucose, or with APMA, explants under tension separated at the dermo-epidermal junction. This in vitro separation occurred via 2 different ultrastructural processes. Lack of glucose reduced hemidesmosomes (HDs) numbers until they disappeared and the basal cell cytoskeleton collapsed. Anchoring filaments (AFs), connecting the basal cell plasmalemma to the BM, were unaffected although they failed under tension. APMA activation of constituent lamellar MMPs did not affect HDs but caused AFs to disappear, also leading to dermo-epidermal separation under tension. Conclusions: Natural laminitis may occur in situations where glucose uptake by lamellar basal cells is compromised (e.g. equine Cushing's disease, obesity, hyperlipaemia, ischaemia and septicaemia) or when lamellar MMPs are activated (alimentary carbohydrate overload). Potential relevance: Therapies designed to facilitate peripheral glucose uptake and inhibit lamellar MMP activation may prevent or ameliorate laminitis. [source] Treatment of acute laminitisEQUINE VETERINARY EDUCATION, Issue 5 2003A. H. Parks First page of article [source] The pathogenesis of acute laminitis: fitting more pieces into the puzzleEQUINE VETERINARY JOURNAL, Issue 3 2004S. R. Bailey First page of article [source] Equine laminitis: cryotherapy reduces the severity of the acute lesionEQUINE VETERINARY JOURNAL, Issue 3 2004A. W. Van Eps Summary Reasons for performing study: The hypometabolic and vasoconstrictive effects of cryotherapy could prevent the development of laminitis. Objectives: To use distal limb cryotherapy to prevent laminitis induced by alimentary carbohydrate overload. Methods: Laminitis was induced in 6 Standardbred horses that had one front limb continuously cooled in an ice/water mixture. Lameness evaluation, blinded lamellar histological grading and analysis for lamellar matrix metalloproteinase-2 (MMP-2) mRNA expression were used to evaluate the severity of laminitis. Results: Cryotherapy was well tolerated and effective in cooling the feet. In each horse no lameness was observed in the treated limbs. Laminitis histology scores in the treated limbs were significantly less than those of the corresponding untreated forelimbs (P<0.05). Laminitis histology scores in the treated limbs were also significantly less than those of the untreated limbs (fore- and hind) as a group (P<0.05). Expression of MMP-2 mRNA in the iced feet was significantly (P<0.05) less than that detected in the untreated feet. Conclusions: Cryotherapy, when applied to one foot, markedly reduced the severity of acute laminitis in this study. We propose that vasoconstriction (preventing delivery of haematogenous trigger factors) and hypometabolism (reduction in lamellar MMP activity) were the primary therapeutic mechanisms. Potential relevance: Although further research is needed, we suggest cryotherapy as a potentially effective prophylactic strategy in horses at risk of developing acute laminitis. [source] | ||||||||||