Angiotensin II AT1 and AT2 receptor types regulate basal and stress-induced adrenomedullary catecholamine production through transcriptional regulation of tyrosine hydroxylase

ARMANDO I, JEZOVA M, BREGONZIO C, BAIARDI G, SAAVEDRA JM

Annals of the New York Academy of Sciences

Año: 2004 vol. 1018 p. 302 - 302

he sympathoadrenal response to stress includes a profound increase in adrenomedullary catecholamine synthesis driven by stimulation of tyrosine hydroxylase (TH) transcription. We studied the role of Angiotensin II type 1 and 2 (AT(1) and AT(2)) receptors during isolation stress, and under basal conditions. Pretreatment of rats with the AT(1) receptor antagonist candesartan for 14 days prior to isolation completely prevented the stress-induced stimulation of catecholamine synthesis, decreasing tyrosine hydroxylase transcription by preventing the expression of the transcriptional factor, Fos-related antigen 2 (Fra-2). In addition, AT(1) receptor antagonism prevented the stress-induced increase in adrenomedullary AT(2) receptor binding and protein. Treatment of non-stressed, grouped animals under basal conditions with the AT(1) receptor or with PD 123319, an AT(2) receptor antagonist, decreased the adrenomedullary norepinephrine (NE) content and TH transcription. While AT(1) receptor ant