ABSTRACT
Cardiovascular homeostasis involves a complex interplay among a variety of mechanisms involved in the short- and long-term regulation of the cardiovascular system. While renal mechanisms contribute to the long-term control of blood pressure, neural reflexes play a keen role in the short-term regulation of cardiovascular function. Angiotensin II (ANG II) has been postulated to increase sympathetic outflow by acting in brain areas known to be involved in cardiovascular regulation and by decreasing the sensitivity of the arterial baroreflex. The chapter attempts to clarify the relationship between these major cardiovascular peptide hormones and the regulation of the sympathetic nervous system. Studies in humans have shown that atrial natriuretic peptide (ANP)-induced hypotension is accompanied by an increase in heart rate, suggesting that ANP may not alter the reflex control of the cardiovascular system in humans. Although arginine vasopressin, ANG II, and ANP are the hormones frequently associated with cardiovascular regulation, other hormonal systems have been identified to influence the sympathetic nervous system.
