Subcellular localization of Angiotensin II receptors in Substantia nigra of young and aged rats

ARCE M.E.; CIUFFO G.M.; SÁNCHEZ S.I; BLANCO H.M.

Carlos Paz-Córdoba

Congreso; XXXIV Reunion Anual Sociedad Argentina de Investigacion en Neurociencias (SAN); 2019

Aging is the most prominent risk factor for Parkinson and other neurodegenerative diseases. The Renin Angiotensin System (RAS) regulates multiple physiological functions, activating Angiotensin II (Ang II) type 1 (AT1) and type 2 (AT2) receptors. The presence of both Ang II receptor subtypes have been described in the Substantia nigra (SN) and Ang II receptors considered as participants of neurodegenerative process. We evaluated age-dependent variations in the Ang II receptor immunolocalization in brain sections at the level of SN in young (P21) and aged (P365) male rats. Both Ang II receptors were detected with anti- AT1 and anti AT2 antibodies in 14 μm sections. Young animals evidenced a higher number of AT2 positive neurons than AT1 immunolabeled neurons (38% vs 12% respectively). AT1 receptors localized mainly intracellularly, in a perinuclear localization. The immunohistochemical analysis of AT1 and AT2 receptors showed at P365 a lower density of AT1 cells than AT2 labeled cells ( 8% vs 13% respectively), with cytoplasmic and perinuclear localization. The overall number of immunoreactive cells (AT1 and AT2) diminishes at P365. These results might contribute to a better understanding of the effect of age-related changes in the renin angiotensin system as a crucial part of the aging process and a potential cause for neurodegenerative diseases, including Parkinson disease.