Abstract
An experimental study was done in two rabbits to establish whether the early stages of cartilage generation involves stimulation via the platelet-derived growth factor β receptor (PDGFR-β). Rib perichondrium was dissected off and transplanted to the knee joint. The perichondrial grafts were removed for microscopic investigation at day 0 and day 6 and kept frozen until analysed by immunohistochemistry and in situ hybridisation for the presence of PDGF β receptor protein and mRNA, respectively. Samples from day 0 showed sparse cells with a positive immunohistochemical reaction. In samples from day 6 there were signs of perichondrial proliferation and chondroid maturation and a more widespread immunohistochemical staining reaction could be seen mainly on proliferating perichondrial cells, but also on some chondrocytes. In situ hybridisation confirmed the expression of PDGF β receptor mRNA in the same areas of serial sections. These findings may indicate that PDGF β receptor activity is part of the early response after autotransplantation of perichondrium.