RESUMO
BACKGROUND: The outcome of the autograft therapy for Parkinson's disease including autologous cells from adrenal medulla was disappointing. This could be attributed to the pathological process in Parkinson's disease affecting cells of the adrenal medulla. This study was performed to investigate the histopathological changes in the adrenal medulla of AS/AGU rat, a model of Parkinson's disease, in comparison with Albino Swiss (AS) rats. MATERIALS AND METHODS: A total of 24 male AS rats were divided into four groups, each of 6 animals: AS W1 - AS rats aged 1 week; AS adult - AS adult rats; AS/ /AGU W1 - AS/AGU rats aged 1 week; and AS/AGU adult - AS/AGU adult rats. The rats were sacrificed and the adrenal glands were dissected and processed for histological staining with haematoxylin and eosin and periodic acid Schiff and for immunohistochemical staining for S100 protein, ubiquitin and tyrosine hydroxylase. RESULTS: The histological investigation of the adrenal medulla of AS/AGU rats showed vascular congestion, inflammatory cellular infiltration, pyknotic nuclei, necrotic chromaffin cells and medullary inclusion bodies. The immunohistochemical investigation of AS/AGU rats showed a statistically significant decrease in the expression of S100 protein, ubiquitin and tyrosine hydroxylase compared to AS rats. CONCLUSIONS: The histological and immunohistological changes in the adrenal medulla could explain the failure of outcome of adrenal autograft therapy in Parkinson's disease.