Immunohistochemical localization of angiotensin II receptor types 1 and 2 in the mesenteric artery from spontaneously hypertensive rats

✍ Scribed by Carmen Diniz; Sandra Leal; Karen Logan; Carolina Rocha-Pereira; Ana Sofia Soares; Eduardo Rocha; Jorge Gonçalves; Paula Fresco

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 308 KB
• Volume: 70
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/jemt.20453

✦ Synopsis

Angiotensin II plays a crucial role in the control of blood pressure, acting at AT 1 or AT 2 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 AT 1 and AT 2 receptors on mesenteric artery sections differs in spontaneously hypertensive rats (SHR) versus their respective controls (Wistar-Kyoto [WKY] rats). Immunohistochemistry using anti-AT 1 or anti-AT 2 antibodies was performed on perfused-fixed/paraffin-embedded mesenteric arteries from SHR and WKY rats. 3,3 0 -Diaminobenzidine tetrahydrochloride (DAB; activated by hydrogen peroxide) staining revealed distinct AT 1 and AT 2 labeling of all artery layers (adventitia, media and intima) from WKY rats, whereas in SHR an abundant AT 1 labeling was found in both intima and adventitia and a sparser labeling in the media. There was a vast reduction of AT 2 labeling throughout all layers. These results suggest a crucial role for AT 2 receptors in the pathogenesis of hypertension.