Angiotensin II (3-8), human

Angiotensin II (3-8) is an endogenous C-terminal fragment of the peptide vasoconstrictor angiotensin II .¹ It selectively binds to the angiotensin 2 (AT₂) over AT₁ receptors (IC₅₀s = 48.6 and >1,000 nM, respectively, in HEK293 cells expressing rat receptors). It also binds to AT₄ receptors in bovine aortic endothelial cell membranes (IC₅₀ = 1.6 nM).² Angiotensin II (3-8) induces a positive chronotropic effect in isolated rat right atria (EC₅₀ = 4.68 μM) and increases mean arterial pressure (MAP) in vivo in rats when administrated intracerebroventricularly at a dose of 1 pmol.^3,4 It also increases latency to withdrawal in a tail-flick test in rats when administered by microinjection into the ventrolateral periaqueductal gray (vlPAG).⁵

1.Bosnyak, S., Jones, E.S., Christopoulos, A., et al.Relative affinity of angiotensin peptides and novel ligands at AT1 and AT2 receptorsClin. Sci. (Lond.)121(7)297-303(2011) 2.Bernier, S.G., Bellemare, J.M., Escher, E., et al.Characterization of AT4 receptor from bovine aortic endothelium with photosensitive analogues of angiotensin IVBiochemistry37(12)4280-4287(1998) 3.Li, Q., Zhang, J., Pfaffendorf, M., et al.Direct positive chronotropic effects of angiotensin II and angiotensin III in pithed rats and in rat isolated atriaBr. J. Pharmacol.118(7)1653-1658(1996) 4.Wright, J.W., Jensen, L.L., Roberts, K.A., et al.Structure-function analyses of brain angiotensin control of pressor action in ratsAm. J. Physiol.257(6 Pt. 2)R1551-R1557(1989) 5.Guethe, L.M., Pelegrini-da-Silva, A., Borelli, K.G., et al.Angiotensin (5-8) modulates nociception at the rat periaqueductal gray via the NO-sGC pathway and an endogenous opioidNeuroscience231315-327(2013)