Angiotensin II acts against both the afferent and efferent arterioles via type IA receptor to the same extent, not with predominance of the efferent arteriole--direct evidence using AT1a
ASN 30th Annual Meeting, San Antonio
J Am Soc Nephrol (Sep) 8:301A 1997
In this experimental paper the authors use a mouse model to disprove the idea that angiotensin II affects predominantly the efferent arteriole with minimal effect on the afferent arteriole. They first created AT1 gene deficient mice, substituting the AT1 receptor gene with a reporter gene, which allowed immunochemical localization of the AT1 receptors. These were expressed to a similar extent at the afferent and efferent arterioles. They next did functional studies in mice subjected to ureteral ligation to produce hydronephrosis. This model allows direct microscopic observation of arteriolar diameter in the hydronephrotic kidney. AII constricted both afferent and efferent arterioles to the same extent in mice in which none or half of the AT1 receptors had been replaced by the reporter gener. AII had no effect on either arteriole in mice homozygous for AT1 receptor replacement with the reporter gene.
Comment: This observation, if true in humans, will force us to rethink many of our mechanistic explanations for the effects of ACE inhibitors and AII on glomerular hemodynamics. (John Ball, M.D., Illinois Masonic Hospital, Chicago, IL)
To go back use the BACK button on your browser. Otherwise click on the desired link to this article below:
ASN 30th Annual Meeting, San Antonio
H: Pathophysiology : Kidney in hypertension
H: Drug therapy : ACE inhibitors