November 27, 2022. Renin 1. The Basics

Renin, aka angiotensinogenase, is a 340 amino acid enzyme (which also acts as a hormone). Its molecular weight is 340 kDa.

It is secreted by the juxtaglomerular cells (JG) cells of the juxtaglomerular apparatus in response to 3 stimuli:

• Hypotension (baroreceptors)
• Decreased delivery of sodium or chloride to the distal tubule (macula densa)
• β1 adrenergic stimulation (sympathetic nervous system)

Renin uses its endopeptidase activity to cleave angiotensinogen, to yield angiotensin I. This is the first step in the activation of the renin-angiotensin-aldosterone system (RAAS)

References

https://en.wikipedia.org/wiki/Renin

https://link.springer.com/article/10.1007/BF00584260 - β1 adrenergic stimulation

Kidneys Image obtained from here. Image belongs to the public domain.

Renin Image obtained from here. Image belongs to the public domain.

Juxtaglomerular apparatus picture obtained from here. Author: OpenStax College. Image is under the Creative Commons Attribution 3.0 Unported license