Increased ET(A) and ET(B) receptor contraction in the left internal mammary artery from patients with hypertension.

Patients with hypertension have an increased activity in the endothelin system and an increased vascular tone, which predisposes them to target organ damage. In the present study, in vitro pharmacology, real-time PCR and immunofluorescence techniques were used to show enhanced endothelin type A (ETA) and type B (ETB) receptor contraction and expression in the left internal mammary artery from patients with hypertension as compared to normotensive patients. These receptors may be important in the pathophysiology of hypertension.