Hypertension in rats caused an 18-28% reduction in arteriolar density at 1.5-11 months and an overall 30% decrease in lumen-to-wall ratio (p<0.01), contributing to depressed coronary reserve.
Both hypertension and aging are accompanied by structural alterations of the coronary resistance vasculature, which may contribute to depressed coronary reserve.
p-value: p=<0.01
Coronary reserve has been shown repeatedly to be depressed in hypertension and aging. The underlying mechanisms remain elusive, but structural alterations of the coronary vasculature have been implicated. In this study, we measured maximal coronary dilator capacity and structural characteristics relevant to coronary resistance in aging normotensive (Wistar-Kyoto, n = 22) and spontaneously hypertensive rat (SHR) strains (n = 25) at 1.5, 4, 11, 16, and 22 months of age. Coronary flow measurements, using radiolabeled microspheres, demonstrated a significant (p 50 microns. In addition, there was an overall 30% decrease (p < 0.01) in the ratio of lumen diameter to wall thickness in hypertensive compared with normotensive rats. These data indicate that both hypertension and aging are accompanied by structural alterations of the coronary resistance vasculature. These structural alterations may contribute to the depression in coronary reserve that complicates hypertension and aging.
Vitullo et al. (Thu,) conducted a other in Hypertension and aging (n=47). Hypertension and aging vs. Normotensive rats and younger age was evaluated on Maximal coronary dilator capacity and arteriolar density (p=<0.01). Hypertension in rats caused an 18-28% reduction in arteriolar density at 1.5-11 months and an overall 30% decrease in lumen-to-wall ratio (p<0.01), contributing to depressed coronary reserve.