Alteration in vascular function due to high intravascular pressure: arterial stiffness and the role of beta-adrenoceptors

Background: Hypertension-induced arterial stiffness is associated with high risks of morbidity and mortality. The sympathetic nervous system plays an important role in the control of cardiovascular function through beta-adrenoceptors (β-AR). The involvement of β-AR in the control of arterial stiffness in a state of hypertension and normotension was examined. Methods: Pulse wave velocity (PWV) was assessed within a narrow range of blood pressures in isoflurane-anaesthetized 13-14-week-old male spontaneously hypertensive (SH) and Wistar-Kyoto (WKY) rats. Results: Baseline PWV was higher in SH (9.2±0.9 m/s) compared to WKY rats (6.7±0.4 m/s). The stimulation of β₂- but not β₃-AR reduced PWV in SH rats despite comparable reductions in blood pressure. Sodium nitroprusside infusions initiated a dose-dependent reduction of PWV in SH rats. Conclusion: The evidence suggests that a reduction in central vascular tone may play a key role in decreasing elevated PWV independently from reduction in blood pressure in a state of hypertension.