Immunohistochemical localization of angiotensin II receptor types 1 and 2 in the mesenteric artery from spontaneously hypertensive rats.
Angiotensin II plays a crucial role in the control of blood pressure, acting at AT1 or AT2 receptors, and can act as a potent vasoconstrictor of the peripheral vasculature inducing hypertrophy, hyperplasia, or both, in resistance arteries. The aim of the present study was to investigate whether the pattern of distribution of angiotensin AT1 and AT2 receptors on mesenteric artery sections differs in spontaneously hypertensive rats (SHR) versus their respective controls (Wistar-Kyoto [WKY] rats). Immunohistochemistry using anti-AT1 or anti-AT2 antibodies was performed on perfused-fixed/paraffin-embedded mesenteric arteries from SHR and WKY rats. 3,3'-Diaminobenzidine tetrahydrochloride (DAB; activated by hydrogen peroxide) staining revealed distinct AT1 and AT2 labeling of all artery layers (adventitia, media and intima) from WKY rats, whereas in SHR an abundant AT1 labeling was found in both intima and adventitia and a sparser labeling in the media. There was a vast reduction of AT2 labeling throughout all layers. These results suggest a crucial role for AT2 receptors in the pathogenesis of hypertension.
Diniz
Carmen
C
Serviço de Farmacologia, REQUIMTE, Faculdade de Farmácia, Universidade do Porto, 4050-047 Porto, Portugal. cdiniz@ff.up.pt
Leal
Sandra
S
Logan
Karen
K
Rocha-Pereira
Carolina
C
Soares
Ana Sofia
AS
Rocha
Eduardo
E
Gonçalves
Jorge
J
Fresco
Paula
P
D000818:Animals; D006973:Hypertension / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008638:Mesenteric Arteries / Q000737:chemistry / Q000378:metabolism*; D016612:Paraffin Embedding; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D044140:Receptor, Angiotensin, Type 1 / Q000032:analysis* / Q000378:metabolism; D044139:Receptor, Angiotensin, Type 2 / Q000032:analysis* / Q000378:metabolism
D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2