BRAIN ENDOTHELINS (ETS) CONTRIBUTE TO BLOOD PRESSURE ELEVATION IN DOCA-SALT HYPERTENSION BY ENHANCING CATECHOLAMINERGIC ACTIVITY IN THE OLFACTORY BULB (OB).

GUIL MJ; SORIA C; PANE A; MORALES VP; HOPE S; BIANCIOTTI LG; GIRONACCI M; VATTA MS

IGUASSU FALLS

Congreso; 1ST PANAMERICAN CONGRESS OF PHYSIOLOGICAL SCIENCES; 2014

ASOCIACION LATINOAMERICANA DE CIENCIAS FISIOLOGICAS

In previous studies we reported that ETs regulate catecholaminergic activity in the OB of normotensive rats. The aim of the present work was to evaluate the contribution of brain ETs to blood pressure (BP) elevation in DOCA-salt hypertension and its relationship with the catecholaminergic system in the OB. A guide cannula was placed in the brain lateral ventricle of DOCA-salt hypertensive rats for drug administration, BP was recorded for 60 min following drug injection and OBs were then removed to determine tyrosine hydroxylase (TH) activity and expression as well as the phosphorylated forms of the enzyme. The administration of BQ610 (selective ETA receptor antagonist) significantly reduced blood pressure as well as the activity and expression of TH and its phosphorylated forms. Furthermore, similar results were obtained in the presence of IRL1620 (ETB receptor agonist). In order to determine proteasome system implication in ETs response, animals were pretreated with the proteasome inhibitor MG132 before BQ610 administration. Blockade of proteasome activity partially prevented BQ610 effect. These findings show that in DOCA-salt hypertension ETs through ETA receptors increase catecholaminergic activity by enhancing TH activity in the OB, supporting that ETs contribute to hypertension in this animal model.