Protocol on induction of TMJ articular disc degeneration in rats by utilization of botulinum toxin

ObjectiveTo develop a model of experimental degeneration in the articular disc of the TMJ of rats through the use of botulinum toxin that can be used in future studies of degenerative diseases on fibrocartilage.MethodsAiming at the above-mentioned objective, 12 Lewis male rats were used and divided into two groups: CG, control group and DG, group of animals to which the botulinum toxin was administered (6 units/kg). The morphological analysis was carried out utilizing histological cuts stained with hematoxyline-eosine, toluidine blue and Picrosirius; the biochemical analysis was made by SDS-polyacrylamide gel electrophoresis.ResultsThe DG showed peculiar characteristics regarding a degeneration joint disk, compatible with those described in literature as: reduction of cells number, general disorganization of cells direction and extracellular matrix, increase in glycosaminoglycans content and degradation of the tissue collagen.ConclusionsBased on the morphological and biochemical results, it was concluded that the proposed degeneration model showed to be satisfactory for futures studies of injuries and fibrocartilage regeneration processes.