Fig. 4

Histological finding in the articular cartilage of the rats’ facet joints L3-L4. High-fat diet: b areas without cells, uneven colouring of the matrix, growth of blood vessels into the articular cartilage, and empty lacunae, Hematoxylin and Eosin stain (H&E); e intensity of the Alcian blue matrix staining (cyan colour) around these clusters significantly lower than control, Picrosirius Red/Alcian Blue stain (P&A). Compression: c marked degenerative changes in the articular cartilage: cell death, necrotic areas, H&E; f decrease in glycosaminoglycan concentration (absent of cyan colour) compared to the control, P&A