Discontinuities in the endothelium of epiphyseal cartilage canals and relevance to joint disease in foals

摘要: Cartilage canals have been shown to contain discontinuous blood vessels that enable circulating bacteria bind cartilage matrix, leading vascular occlusion and associated pathological changes in pigs chickens. It is also inconsistently reported are surrounded by a cellular or acellular wall may influence whether bacterial binding can occur. not known equine endothelium wall. This study aimed examine there were discontinuities the of canal vessels, had wall, epiphyseal growth foals. Epiphyseal from proximal third medial trochlear ridge distal femur six healthy foals 1, 24, 35, 47, 118 122 days old different breeds sexes was examined light microscopy (LM), transmission electron (TEM) immunohistochemistry. The majority patent contained lined thin layer continuous endothelium. Fenestrations found two locations one venule located deep close ossification front 118-day-old foal. Chondrifying all TEM-examined degenerated endothelial cells detached basement membrane, resulting gap formation. Thirty-three percent hypercellular rim interpreted as contribution chondrocytes cartilage. On LM, 69% ring matrix stained intensely eosinophilic consisted collagen fibres on TEM confirmed be type I In summary, types discontinuity observed vessels: fenestrations foal; gaps chondrifying Canals any but large proportion an consisting I. Bacterial therefore probably occur horses mechanisms similar those previously demonstrated