More recently, a third-level of RAS (i.e. intracellular/intracrine) has been suggested in peripheral tissues.10, 11 The system may be activated by AII internalized using AT1 receptors or by intracellularly synthesized AII.12 Immunohistochemical studies suggest an apparent intracellular localization of several RAS components in the SNc of mammals, including primates and humans.5, 13 Mitochondrial dysfunction plays a major role in several neurodegenerative disorders, particularly in the degeneration of dopaminergic neurons in Parkinson's disease (PD). This evidence concerns the gene AGTR1 and Parkinson disease.