Jpn. J. Pharmacol. 84 (1), 75-77 (2000)

Cardiac Angiotensin II Receptors Are Downregulated by Chronic Angiotensin II Infusion in Rats

Makoto Katoh1,2, Kensuke Egashira2 and Akira Takeshita2

1Discovery Research Laboratory, Tanabe Seiyaku Co., Ltd., 2-2-50, Kawagishi, Toda, Saitama 335-8505, Japan
2The Department of Cardiovascular Medicine, Kyushu University Faculty of Medicine, 3-3-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan

Abstract: 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.

Keywords: Angiotensin II, Angiotensin receptor, Rat left ventricle

Copyright© The Japanese Pharmacological Society 2000

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