The Cardiovascular Clock

This chapter discusses the importance of the circadian clock and circadian rhythms with regard to their significance in cardiovascular cell signaling, blood pressure control, vascular function, and disease based on insights from human physiology and experimental animal models. Signals with established roles in the control of vascular contractility, tone, and remodeling also impart a significant influence on the circadian clock. These include endothelin, prostanoids, angiotensin (AT), and even nitric oxide (NO). The disturbances in blood pressure rhythm cause increased cardiovascular disease and death. Recent basic science studies have further implicated the circadian clock in the control of blood pressure. While obesity and metabolic dysfunction are major risk factors for the impaired control of blood pressure, recent evidence has also implicated the circadian clock. There are different animal models with mutations in renin-angiotensin system (RAS) pathway that exhibit hypertension and defects in blood pressure circadian rhythm.