Does angiotensin 2 causes vasoconstriction of arteries or arterioles
Reading File
Finding Sources
Searching PubMed
"Angiotensin II"[MeSH Terms] AND "Vasoconstriction"[MeSH Terms]
Angiotensin II constricts arterioles, and this is its main vascular action. It constricts veins much less.
Guyton and Hall states that angiotensin II causes vasoconstriction "intensely in the arterioles and less so in the veins." Constricting the arterioles raises total peripheral resistance, which raises arterial pressure. The mild venous constriction increases venous return to the heart, which also supports cardiac output (Guyton and Hall Textbook of Medical Physiology, Components of the Renin-Angiotensin System).
- Arterioles: these are the resistance vessels. They have a thick smooth muscle layer and set systemic vascular resistance. Angiotensin II acts on AT1 receptors on their smooth muscle, which activates Gq/PLC and raises intracellular Ca²⁺. This is why it is such a potent pressor.
- Arteries: the large conduit arteries are affected only slightly. They do not contribute much to resistance.
- Veins: the effect is mild, as above.
- Efferent arterioles: angiotensin II constricts these preferentially in the kidney. That maintains glomerular filtration pressure when renal perfusion falls.
ACE inhibitors work the other way. Lowering angiotensin II dilates both arterioles and veins. Part of the effect also comes from raised bradykinin (Lippincott Illustrated Reviews: Pharmacology, Actions).
A recent systematic review on the direct vascular effects of angiotensin II (PMID 39795971, 2024) looks at its signalling in vascular smooth muscle. I searched for recent evidence and found nothing that contradicts the textbook account. I did not read the full text of that review.
This is a shared conversation. Sign in to Orris to start your own chat.