Cardiac angiotensin II receptors are downregulated by chronic angiotensin II infusion in rats.
We studied the effect of chronic (7 days) angiotensin II infusion in a subpressor (200 ng/kg per minute) dose on angiotensin II receptors in the left ventricle in rats. Infusion of angiotensin II caused an elevation in systolic blood pressure after 3 days, usually to values of about 150 mmHg, and the increase continued during the drug administration. The number of angiotensin II type 1 and angiotensin II type 2 receptors was significantly decreased by 20-30% in the angiotensin II-infused left ventricular membranes without affecting the affinity. Thus, these data suggest that angiotensin II may regulate the number of its own receptors in rat left ventricles.
Kato
M
M
Discovery Research Laboratory, Tanabe Seiyaku Co, Ltd, Toda, Saitama, Japan.
Egashira
K
K
Takeshita
A
A
D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D015536:Down-Regulation; D004333:Drug Administration Routes; D006352:Heart Ventricles / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011921:Rats, Inbred WKY; D011945:Receptors, Angiotensin / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*; D016277:Ventricular Function, Left
D011945:Receptors, Angiotensin; D014662:Vasoconstrictor Agents; D000804:Angiotensin II