Steroidogenic
acute regulatory
protein,
mitochondrial
Gγ
Cholesterol
side-chain
cleavage enzyme,
mitochondrial
Cytochrome P450
11B2,
mitochondrial
Cytochrome P450
11B2,
mitochondrial
Cytochrome P450
11B2,
mitochondrial
Steroid
21-hydroxylase
3 beta-
hydroxysteroid
dehydrogenase/Delta
5-->4-isomerase
type 1
Gγ
Type-1
angiotensin II
receptor
Type-1
angiotensin II
receptor
Gβ
Gβ
Gαq
Gαq
Angiotensin II
Deoxycorticosterone
Deoxycorticosterone
Pregnenolone
Pregnenolone
Cholesterol
O2
H+
Corticosterone
H2O
O2
18-
Hydroxycorticosterone
H2O
O2
Aldosterone
H2O
Progesterone
O2
H2O
NAD
NADH
H+
Aldosterone
Heme
Heme
Heme
Heme
GDP
GTP
Angiotensin II
Reduced adrenal
ferredoxin
Oxidized
adrenal
ferredoxin
Reduced adrenal
ferredoxin
Oxidized
adrenal
ferredoxin
Reduced adrenal
ferredoxin
Oxidized
adrenal
ferredoxin
Reduced
acceptor
Acceptor
Heme
Zona Glomerulosa Cell
The GPCR activates the G
protein by exchanging GDP
for GTP. This exchange
triggers the dissociation of
the Gα subunit from the Gβγ
dimer and the receptor.
Angiotensin II from the
circulation travels to the
adrenal cortex through the
suprarenal and capsular
arteries
Capsular Artery
Signaling cascade that
activates the steroidogenic
acute regulatory (StAR)
protein which triggers
cholesterol uptake into the
mitochondria
Mitochondrion
Smooth Endoplasmic Reticulum
Transported into the
mitochondrion
Adrenal Cortex
Aldosterone synthesized from
the mitochondria primarily
acts on the collecting duct
in addition to the distal
convoluted tubule to
stimulate reabsorption of
Na+
Aldosterone goes to act on
nephron collecting duct and
distal convoluted tubule