Depressor role of angiotensin AT2 receptors in the (mRen-2)27 transgenic rat

American Journal of Hypertension
T NishiokaM F Callahan

Abstract

The (mRen-2)27 transgenic rat (Tg+), a hypertensive model dependent on increased expression of the renin angiotensin system, was used to explore the role of angiotensin AT2 receptors in the control of cardiovascular and renal excretory function. Experiments tested the effect of blockade of AT2 receptors on basal blood pressure and the pressor, renal excretory, and vasopressin (VP) responses to intravenous hypertonic saline (HS). Chronically catheterized male Tg+ and normotensive Sprague-Dawley rats (Tg-) were housed in metabolic cages. PD123319 (AT2 antagonist) or 0.9% NaCl was given by intravenous bolus (3 mg/kg) followed by infusion (50 microg/kg/ min). Blockade of AT2 receptors both in Tg+ and Tg- rats produced no change in basal mean arterial pressure (MAP). The pressor response to intravenous HS (10% NaCl; 325 microL/100 g body weight) was significantly greater in Tg+ than in Tg- rats. PD123319 did not affect the peak rise in MAP but extended the time course of the response only in Tg+ rats. MAP was increased 39+/-4 and 36+/-3 mm Hg in Tg+ rats with and without the antagonist as compared to 20+/-2 and 24+/-2 mm Hg in Tg- rats. In the antagonist-treated Tg+ rats, MAP remained elevated for 60 min as compared to 5 min for Tg+...Continue Reading

Citations

Apr 24, 2007·American Journal of Physiology. Heart and Circulatory Physiology·Vera FarahMariana Morris
Dec 17, 2002·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Shigefumi NakamuraCarlos M Ferrario
Oct 22, 2002·American Journal of Physiology. Heart and Circulatory Physiology·Zhen LiMasatsugu Horiuchi
Jan 15, 2004·The Journal of Pharmacology and Experimental Therapeutics·Bradley T AndresenEdwin K Jackson
Mar 11, 2000·American Journal of Physiology. Endocrinology and Metabolism·S GallinatC Sumners

❮ Previous
Next ❯

Related Concepts

Related Feeds

Antihypertensive Agents: Mechanisms of Action

Antihypertensive drugs are used to treat hypertension (high blood pressure) which aims to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Discover the latest research on antihypertensive drugs and their mechanism of action here.