New insight and therapeutic strategies in cardiovascular disease and focus on endothelial target: endothelin-1 and angina

Old and New Biomarkers Associated with Endothelial Dysfunction in Chronic Hyperglycemia

Chronic hyperglycemia and vascular damage are strictly related. Biomarkers of vascular damage have been intensively studied in the recent years in the quest of reliable cardiovascular risk assessment tools able to facilitate risk stratification and early detection of vascular impairment. The present study is a narrative review with the aim of revising the available evidence on current and novel markers of hyperglycemia-induced vascular damage. After a discussion of classic tools used to investigate endothelial dysfunction, we provide an in-depth description of novel circulating biomarkers (chemokines, extracellular vesicles, and epigenetic and metabolomic biomarkers). Appropriate use of a single as well as a cluster of the discussed biomarkers might enable in a near future (a) the prompt identification of targeted and customized treatment strategies and (b) the follow-up of cardiovascular treatment efficacy over time in clinical research and/or in clinical practice.

ETA receptors mediate vasoconstriction of large conduit arteries during reduced flow in humans

Vascular tone is regulated by endothelium-derived vasodilating and constricting substances, mainly nitric oxide and endothelin (ET)-1. These 2 mediators, which antagonize the actions of each other, are released in response to shear-stress produced by blood flow. The aim of this study was to delineate the contribution of endogenous ET-1 on vascular tone of a large conduit artery during reduced and hyperemic flow. Radial artery diameter was continuously measured with a high-resolution ultrasonic echo-tracking device in 8 healthy subjects. After establishing stable baseline conditions, a wrist cuff was inflated to suprasystolic pressure for 5 minutes. In another 5 subjects, measurements were obtained during intraarterial infusion of saline or an ETA receptor antagonist (BQ-123, 1 nmol/min) in a dosage not affecting basal radial diameter. Wrist occlusion caused a progressive vasoconstriction of the radial artery (P = 0.0001). Vasoconstriction of the radial artery during wrist occlusion was significantly attenuated by ETA receptor antagonism (-2.7% +/- 0.6% versus -6.8% +/- 0.6% during saline, P = 0.007). Flow-mediated vasodilation was not influenced by BQ-123 (7.5% +/- 0.8% versus 7.8% +/- 1.1%, P = NS). This study demonstrates active vasoconstriction of large conduit arteries during conditions of reduced blood flow via ETA receptoractivation. This may play an important role in disease states with reduced systemic or local blood flow and indicates the therapeutic potential of ETA receptor antagonism.

Sickle cell crisis and endothelin antagonists

Sickle cell crisis may be more complex than a vaso-occlusive event in response to hypoxia. Endothelin-1 (ET-1) is a potent vasoconstrictor and mitogen secreted in response to hypoxia. ET-1 contributes to the vaso-occlusion and inflammation in sickle cell crisis. ET-1 antagonists may be useful in the prevention and treatment of crisis.