Physiological evolution of the renin-angiotensin system

Area of Science:

• Comparative physiology
• Evolutionary biology
• Endocrinology

Background:

• The renin-angiotensin system (RAS) regulates blood pressure and aldosterone secretion in mammals.
• Renin release is influenced by intrarenal receptors, the sympathetic nervous system, and humoral agents.
• Interactions between RAS, prostaglandins, and the kallikrein-kinin system are subjects of recent research.

Purpose of the Study:

• To investigate the evolutionary history of the renin-angiotensin system (RAS) across vertebrate classes.
• To explore the functional roles of RAS components in primitive vertebrates compared to mammals.
• To understand the relationship between RAS evolution and blood pressure homeostasis.

Main Methods:

• Comparative analysis of anatomical and physiological data across diverse vertebrate species.
• Review of studies on renin release mechanisms and the effects of angiotensin administration.
• Examination of evolutionary emergence of RAS components like juxtaglomerular (JG) cells and macula densa.

Main Results:

• Renal renin and JG cells evolved early in bony fishes; the macula densa evolved later.
• Angiotensins and renin exhibit vasopressor and mineralocorticoid-stimulating effects across vertebrates.
• RAS appears linked to blood pressure homeostasis, with evidence of JG cell evolution preceding macula densa.

Conclusions:

• The RAS evolved in close association with blood pressure regulation, originating in primitive vertebrates.
• Some RAS functions observed in mammals may be evolutionary relics from more critical roles in primitive animals.
• Comparative studies offer valuable insights into the fundamental mechanisms of the RAS.