renin
Last reviewed 11/2023
Renin is a proteolytic enzyme stored in an inactive form within the juxtaglomerular apparatus of the kidneys. Microscopically, renin granules can be seen within modified smooth muscle cells in close proximity to both the macula densa of the distal tubule and the afferent arteriole.
In response to a number of stimuli - see submenu, renin is secreted into the afferent arteriole to act on the circulating protein, angiotensinogen, converting it to the decapeptide angiotensin I.
Reference range for renin:
- standing 0.76-3.20 nmol/L/hr
- supine 0.39-2.03 nmol/L/hr
Note that reference ranges may vary between laboratories.