AT(1) receptors: Coronary flow and flow reserve

Angiotensin II, through its effects at the angiotensin-type 1 receptor, ele vates arterial pressure and exacerbates hypertensive heart disease. Alterat ions in coronary hemodynamics, including reductions in coronary blood now a nd now reserve promotes coronary insufficiency and contributes to the incre ased cardiovascular risk associated with these conditions. In spontaneously hypertensive rats, coronary now reserve, the difference between basal coro nary blood flow and the flow achieved during maximal coronary vasodilation achieved by dipyridimole, was increased to a greater extent after treatment for 3 months with an angiotensin II receptor blocker as compared with an a ngiotensin converting enzyme inhibitor. The combination of the two agents, in equidepressor doses, almost restored coronary flow reserve to levels see n in normotensive Wistar Kyoto rats. This finding suggests a possible advan tage of combination angiotensin converting enzyme inhibitors and angiotensi n II receptor blocker therapy in patients with hypertension and hypertensiv e heart disease. Am J Hypertens 2000; 13:39S-44S (C) 2000 American Journal of Hypertension, Ltd.