Equine laminitis: ultrastructural lesions detected 24–30 hours after induction with oligofructose

Abstract

Hindgut events occurring in the first 24 h after dosing have begun the destruction of the hoof lamellar interface. Prevention and treatment strategies should precede lameness if they are to be efficacious.

Drug delivery to equine digital lamellar tissue

“…Similar ultrastructural lesions are present at 24 hours post-OF-induction (Nourian, Baldwin et al 2007). …”

“…Decreased expression of the integrin α6β4 subunit in the acute phase of laminitis also occurs (French 2002), thus loss and dysfunction of the α6β4 subunit may contribute to Ln-332 disengagement and subsequent lamellar failure. Whilst, no consistent change in integrin α6β4 gene expression has been detected (Visser 2009), changes may be occurring at the protein level and this theory fits with the reduction in HD numbers in areas of dermo-epidermal separation Nourian, Baldwin et al 2007). …”

“…Grade 1 changes are typified by narrowed, elongated SEL with pointed tips; rounded and abnormally located EBC nuclei; detachment of the BM at the SEL tips to form teat-shaped bubbles and loss of BM staining at the base of the SEL. Lamellar lesions present during the developmental phase, between 18 and 30 hours post induction with OF, are often consistent with Grade 1 lesions (Croser 2006;Nourian et al 2007). However, histological changes that are milder than typical Grade 1 lesions have been detected at 12 hours post OF induction.…”

Alterações morfológicas de tecido laminar do casco e parâmetros clínicos e laboratoriais de equinos com síndrome cólica letal

“…Uma dessas, a teoria enzimática, sugere a ativação de MMPs por leucócitos, citocinas inflamatórias ou toxinas bacterianas, causando degradação do colágeno presente na membrana basal e perda das interdigitações entre as lâminas dérmicas e epidérmicas (Pollitt 1999), e sugere-se que estes fatores ativadores das MMPs possam estar no tecido laminar em menos de 24 horas após o início do processo primário (Loftus et al 2007a, Nourian et al 2007.…”

Equine laminitis: a tissue microdialysis study of lamellar bioenergetics

“…Rounding of EBC nuclei, elongation of the tips of the SEL, and loss of attachment of EBC to their BM occurs as the BM disintegrates (Pollitt, 1996a;Pollitt and Daradka, 1998). At ultrastructural, subcellular level, HDs are disassembled and lost in a manner that correlates with the severity of laminitis, at least in experimental subjects (French and Pollitt, 2004b;Nourian et al, 2007). The separation of EBC from their BM is associated with this HD disassembly, and the rounding of EBC nuclei is the result of collapse of the cellular cytoskeleton.…”