Hypertension I: Structure of Small Arteries in Hypertension

0662 Struijker-Boudier Arteriolar growth and vascular resistance

Dear Dr. Struijker-Boudier:
In your introduction you mention that it is not clear if arteriolar rarefaction is an adaptation to hypertension rather than a possible contributing factor. We have shown that rarefaction develops after the pressure begins to rise. The arterioles first go through a period of functional rarefaction where they are closed to flow but can be opened with vasodilators. After more time, the closed vessels are lost completely. This occurs in the SHR as well as renal hypertensive models where there is no genetic predisposition for rarefaction. Both rarefaction and inward, eutrophic remodeling were not seen in the cremaster muscle of rats subjected to aortic coarctation, suggesting that pressure is the stimulus for both of these phenomena. Would you agree that these results suggest that rarefaction is an adaptation to elevated pressure?

Fri Dec 11