Expression and functional role of urotensin-II and its receptor in the adrenal cortex and medulla: novel insights for the pathophysiology of primary aldosteronism.
BACKGROUND
The involvement of urotensin II, a vasoactive peptide acting via the G protein-coupled urotensin II receptor, in arterial hypertension remains contentious.


OBJECTIVE
We investigated the expression of urotensin II and urotensin II receptor in adrenocortical and adrenomedullary tumors and the functional effects of urotensin II receptor activation.


METHODS
The expression of urotensin II and urotensin II receptor was measured by real time RT-PCR in aldosterone-producing adenoma (n = 22) and pheochromocytoma (n = 10), using histologically normal adrenocortical (n = 6) and normal adrenomedullary (n = 5) tissue as control. Urotensin II peptide and urotensin II receptor protein were investigated with immunohistochemistry and immunoblotting. To identify urotensin II-related and urotensin II receptor-related pathways, a whole transcriptome analysis was used. The adrenocortical effects of urotensin II receptor activation were also assessed by urotensin II infusion with/without the urotensin II receptor antagonist palosuran in rats.


RESULTS
Urotensin II was more expressed in pheochromocytoma than in aldosterone-producing adenoma tissue; the opposite was seen for the urotensin II receptor expression. Urotensin II receptor activation in vivo in rats enhanced (by 182 +/- 9%; P < 0.007) the adrenocortical expression of immunoreactive aldosterone synthase.


CONCLUSIONS
Urotensin II is a putative mediator of the effects of the adrenal medulla and pheochromocytoma on the adrenocortical zona glomerulosa. This pathophysiological link might account for the reported causal relationship between pheochromocytoma and primary aldosteronism.
Giuliani
Luisa
L
Department of Clinical and Experimental Medicine, Internal Medicine 4, School of Medicine, University of Padua, Padua, Italy.
Lenzini
Livia
L
Antonello
Michele
M
Aldighieri
Enrico
E
Belloni
Anna S
AS
Fassina
Ambrogio
A
Gomez-Sanchez
Celso
C
Rossi
Gian Paolo
GP
D000236:Adenoma / Q000150:complications / Q000235:genetics / Q000378:metabolism; D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism*; D000310:Adrenal Gland Neoplasms / Q000150:complications / Q000235:genetics / Q000378:metabolism; D000313:Adrenal Medulla / Q000378:metabolism*; D000328:Adult; D000818:Animals; D019405:Cytochrome P-450 CYP11B2 / Q000235:genetics / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D006929:Hyperaldosteronism / Q000209:etiology* / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D010673:Pheochromocytoma / Q000150:complications / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D014579:Urotensins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*
D043562:Receptors, G-Protein-Coupled; C121697:UTS2R protein, human; D014579:Urotensins; C029677:urotensin II; D019405:Cytochrome P-450 CYP11B2