Activation of ET-B1 receptors on the endothelium causes vasodilatation by inducing the release of NO and PGI2 [73, 74]. In ED, ET-B1 receptors on the endothelial cells are downregulated, while ET-B2 receptors on smooth muscle cells are upregulated, thus enhancing vasoconstriction [75, 76].
Do endothelial cells cause vasoconstriction?
When endothelial damage occurs, the endothelium produces less nitric oxide and prostacyclin, which causes the adrenergic vasoconstrictor tone to be unopposed. This can lead to increased vascular tone and vasospasm.
How do endothelial cells regulate blood pressure?
In healthy blood vessels, the endothelial cell lining of blood vessels (the endothelium) controls vascular reactivity (and hence blood pressure) by releasing paracrine signaling molecules, such as nitric oxide (NO) and prostacyclin.
