IQUIMEFA   05518
INSTITUTO QUIMICA Y METABOLISMO DEL FARMACO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Catecholaminergic activity in the olfactory bulb of DOCA-salt hypertensive rats following central ETB stimulation.
Autor/es:
MERCEDES SCHOLLER; MARCELO S. VATTA; MARIA JULIA GUIL; LILIANA G. BIANCIOTTI; LUIS CASSINOTTI
Lugar:
Praga
Reunión:
Congreso; The Fifteenth International Conference on Endothelin; 2017
Resumen:
We previously reported that endothelins (ETs) regulate catecholaminergic activity in the olfactory bulb in normotensive and hypertensive animals. Acute administration of an ETA antagonist decreases blood pressure (BP) in DOCA-salt hypertensive rats along with a reduction in tyrosine hydroxylase (TH) activity, phosphorylation (P-TH), protein expression and mRNA levels, through a proteasome dependent mechanism. In the present study, we sought to establish the role of brain ETB receptors on BP regulation and its relationship with the catecholaminergic system within the OB of DOCA-salt rats. We characterized ETA and ETB distribution, along with TH, and evaluated the effect of IRL1620 (ETB agonist) applied to the brain, on BP and TH. Hypertensive rats showed higher TH and ETA levels in the glomerular area, with an increase in ETA-TH and ETB-TH co-localization. IRL1620 significantly reduced BP, as well as TH activity, P40-TH and P19-TH, and TH mRNA levels. These findings suggest that that DOCA-salt hypertension depends on endogenous central ETA activity, rather than on ETB, and that low ETB stimulation is essential for blood pressure elevation in this animal model. The effect of ETA antagonism may also result from ETB overstimulation. The present study show that the ET receptors are involved in TH regulation in the OB and such changes are likely implicated in the hemodynamic regulation and sympathetic outflow.