Age-related changes in Ang II receptor´s immunolocalization and expression in the Substantia nigra

ARCE MARIA ELENA; BRUERA MANUEL; SANCHEZ SUSANA INES; CIUFFO GLADYS MARIA

Córdoba

Congreso; XXXIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2019

Sociedad Argentina de Investigación en Neurociencias

Substantia nigra (SN) is the main source of dopamine and a critical area in Parkinson Disease (PD). Overstimulation of Ang II AT1 receptors could produce oxidative stress, which affect the sensitive area of the SN. Thus, we evaluated developmental changes in Ang II receptor´s expression and localization in this area. Animals of P21, P100 and P365 days were used. For RNA extraction, the SN was dissected from slides obtained with a cryostat at the adequate level. RT-PCR assays allowed us to observe a decrease in the expression level of both AT1 and AT2 receptors with age. AT1 receptors decreased about 80% at P100, while AT2 receptors showed no significant difference between P21 and P100. Both receptors diminished at P365. Immunofluorescence staining of AT1 and AT2 receptors showed at P21 and P100 higher density of AT2 stained cells than AT1 labeled cells, with citoplasmatic and perinuclear localization. The number of stained cells diminishes at the stage P365. These results might account for the natural process encompassing aging. There are no previous reports regarding Ang II receptor localization in the SN by immunofluorescence at different ages. A new role has been proposed for Ang II AT2 receptors as neuroprotector, since its actions counteracts the damage cause by oxidative stress due to AT1 receptors. Our present results confirm the presence of both receptors during aging with a lower level of AT1 receptors and provide information of potential use for future treatments.