The effect of simvastatin and pravastatin on arterial blood pressure, baroreflex, vasoconstrictor, and hypertensive effects of angiotensin II in Sprague-Dawley rats

Research suggests that statins affect the regulation of arterial blood pressure (BP), however, the mechanisms remain obscure. We maintained male, 12 week old, Sprague Dawley rats on tap water (controls) or water containing simvastatin or pravastatin for 4 weeks. Subsequently, we measured mean arterial blood pressure and heart rate at baseline and after intravenous infusion of either saline or angiotensin II (Ang II). Additionally, we tested baroreflex function and the effect of statins on vasoconstrictor response to Ang II on isolated femoral artery branches. Controls and simvastatin and pravastatin groups showed a significant increase in mean arterial BP and heart rate in response to Ang II. The increase was significantly smaller in the simvastatin group than in controls and in the pravastatin group. In contrast, when pretreated with hexamethonium, a ganglionic blocker, simvastatin and pravastatin groups showed a similar hypertensive response to Ang II, which was smaller than in controls. Likewise, the Ang II induced vasoconstrictor response of femoral artery branches was comparable between simvastatin and pravastatin groups and smaller than in controls. We found no effect of statins on the baroreflex. This study shows that simvastatin and pravastatin differ in their effects on the Ang II dependent mechanisms controlling BP. (C) 2014 American Society of Hypertension. All rights reserved.