F. Bonnet et al., Vascular expression of angiotensin type 2 receptor in the adult rat: influence of angiotensin II infusion, J HYPERTENS, 19(6), 2001, pp. 1075-1081
Citations number
42
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Objective The aim of this study was to investigate the relative role of the
angiotensin type 1 (AT(1)) and type 2 (AT(2)) receptors in mediating angio
tensin Ii-induced regulation of AT(2) receptor in mesenteric artery.
Design Sprague-Dawley rats were infused with either angiotensin II or vehic
le for 14 days at a dose of 58.3 ng/ min, Ang Ii-infused rats were allocate
d to receive either an AT(1) antagonist, valsartan at a dose of 30 mg/kg pe
r day or the AT(2) receptor antagonist PD123319 at a dose of 830 ng/min.
Methods Gene and protein expression of the AT(2) receptor in the mesenteric
vasculature was assessed by quantitative reverse transcriptase polymerase
chain reaction, immunohistochemistry and by in vitro autoradiography with a
specific radioligand, (1251)-CGp 42112B.
Results The AT(2) receptor mRNA and protein were detected in the mesenteric
artery from adult rats, Both nuclear emulsion and immunohistochemical stai
ning showed expression of the AT(2) receptor in the adventitial and medial
layers. Compared to control rats, angiotensin II infusion was associated wi
th a significant increase in the AT2 receptor expression, Valsartan treatme
nt significantly reduced AT(2) receptor gene expression, with no significan
t effect of PD123319 on this parameter.
Conclusions This study confirms that the presence of the AT(2), receptor in
mesenteric arteries in adult rats, shows an up-regulation of the AT(2) rec
eptor following angiotensin II infusion and suggests a role for the AT(1) r
eceptor in this regulation, In view of the recently demonstrated effects of
the AT(2) receptor, these findings may be relevant to the role of the AT(2
) receptor in the pathophysiology of vascular remodeling.