Angiotensin II AT(1) and AT(2) receptors contribute to maintain basal adrenomedullary norepinephrine synthesis and tyrosine hydroxylase transcription.

JEZOVA M, ARMANDO I, BREGONZIO C, YU ZX, QIAN S, FERRANS VJ, IMBODEN H, SAAVEDRA JM

ENDOCRINOLOGY

Año: 2003 vol. 144 p. 2092 - 2092

0013-7227

ngiotensin II (Ang II) AT(1) receptors have been proposed to mediate the Ang II-dependent and the stress-stimulated adrenomedullary catecholamine synthesis and release. However, in this tissue, most of the Ang II receptors are of the AT(2) type. We asked the question whether AT(1) and AT(2) receptors regulate basal catecholamine synthesis. Long-term AT(1) receptor blockade decreased adrenomedullary AT(1) receptor binding, AT(2) receptor binding and AT(2) receptor protein, rat tyrosine hydroxylase (TH) mRNA, norepinephrine (NE) content, Fos-related antigen 2 (Fra-2) protein, phosphorylated cAMP response element binding protein (pCREB), and ERK2. Long-term AT(2) receptor blockade decreased AT(2) receptor binding, TH mRNA, NE content and Fra-2 protein, although not affecting AT(1) receptor binding or receptor protein, pCREB or ERK2. Angiotensin II colocalized with AT(1) and AT(2) receptors in ganglion cell bodies. AT(2) receptors were clearly localized to many, but not all, chromaffin ce