title: Detection of calprotectin and apoptotic activity within the equine colon from horses with black walnut extract-induced laminitis.
abstract: The black walnut extract (BWE) model of equine laminitis is associated with a systemic inflammatory response manifest by increased expression of inflammatory cytokines in the lungs and liver as well as the laminae. The specific role of the gastrointestinal tract in development of this response is unclear and is of utmost importance, as gastrointestinal disease and laminitis are intimately related. We investigated calprotectin expression and epithelial and endothelial apoptosis in the colon of horses exposed to orally administered BWE. Sections of colon from 19 horses including 7 controls not exposed to BWE, 6 horses at the developmental time-point of leukopenia (DTP) and 6 at the onset of Obel grade 1 laminitis (LAM) after BWE-administration were histologically examined. Immunohistochemical evaluation for calprotectin expression with MAC 387 antibody was performed along with assessment of epithelial and endothelial apoptosis with caspase-3 active antibody. Calprotectin expression and percentage of apoptotic cells were compared between controls and the two treatment groups and presence of a correlation between calprotectin expression and apoptosis was evaluated. Histological findings from BWE-treated horses included eosinophil and lymphocyte epitheliotropism. The DTP group had a higher (p<0.01) calprotectin score with respect to the control group, while there was no significant difference in percentage of epithelial and endothelial apoptotic cells between groups (p=0.08 and p=0.48 respectively). No significant correlation was found between calprotectin score and epithelial or endothelial apoptosis (p=0.69 and p=0.29 respectively). There is preliminary evidence that exposure of horses to BWE results in an early inflammatory response in the colon. Further studies are needed to characterize the nature of the colonic injury in BWE-exposed horses and the link to the development of laminitis.
authors: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors: Ludovica
authors: L
authors: Chiavaccini
authors: Diana M
authors: DM
authors: Hassel
authors: Megan L
authors: ML
authors: Shoemaker
authors: Joseph B
authors: JB
authors: Charles
authors: James K
authors: JK
authors: Belknap
authors: E J
authors: EJ
authors: Ehrhart
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D003106:Colon / Q000737:chemistry* / Q000473:pathology; D005534:Foot Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D006724:Hoof and Claw / Q000187:drug effects* / Q000473:pathology; D006734:Horse Diseases / Q000139:chemically induced* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006736:Horses; D007413:Intestinal Mucosa / Q000737:chemistry / Q000473:pathology; D031324:Juglans / Q000633:toxicity; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis* / Q000502:physiology; D010936:Plant Extracts / Q000633:toxicity
chemical_list: D039841:Leukocyte L1 Antigen Complex; D010936:Plant Extracts