Smooth muscle hypertrophy and arterial remodelling in deoxycorticosterone acetate-salt hypertension.

Morphometric analyses were made of medial-intimal cross-sectional area and lumen diameter in transverse sections of large arteries and small arterioles from normal and deoxycorticosterone acetate-salt hypertensive animals whose vasculatures were perfusion fixed at their in vivo mean arterial pressures. During the borderline and established phases of hypertension, changes in medial cross sectional area and lumen diameter were not detected in any vessel. During chronic mineralocorticoid hypertension, significant (p < 0.05) medial hypertrophy and an increased lumen diameter were found in the abdominal aorta whereas these parameters were normal in other large conduits, small arteries, and arterioles examined. These results indicate that medial hypertrophy is a late consequence of chronic hypertension in this model and is confined primarily to the abdominal aorta. Further, remodelling without medial hypertrophy may explain the normal lumen diameters of small arteries and arterioles in this model of hypertension.