Caveolae are plasma membrane invaginations enriched with high cholesterol and
sphingolipid content; they also contain caveolin proteins in their structure. Endothelial nitric
oxide synthase (eNOS), an enzyme that synthesizes nitric oxide (NO) by converting L-
arginine to L-citrulline, is highly concentrated in plasma membrane caveolae. Hypertension
is associated with decreased NO production and impaired endothelium-dependent
relaxation. Understanding the molecular mechanisms that follow hypertension is important …

Results Caveolae disruption reduced acetylcholine (ACh)-induced endothelium-dependent
relaxation. ACh-induced endothelium-dependent relaxation decreased in the SHR aortas
(Fig. 1A) and mesenteric arteries (Fig. 1B). In the aortas, stimulation with ACh elicited similar
maximum relaxant effects in normotensive rats (98.4±0.3%, n= 5) and SHRs (89.6±0.6%, n=
7), but the ACh potency was lower in the SHR aortic rings (pD2: 5.75±0.4, n= 7) than in the
normotensive rat aortic rings (pD2: 6.51±0.1, n= 5). On the other hand, the ACh potency …