ACE INHIBITORS
Overview of RAAS
Maintain ance of volume
circulatory
and b p
Activated when volume 1 pressure
falls or glometular filtration is
reduced
Angiotensin II promotes
vas constriction
and aldosterone
vas pressin
secretion
promotes Nat and
H2O retention
Also mediates vascular and cardiac
growth structural
remodelling and enhances NA release from sympathetic
nerves
3 mechanisms of renin secretion
In response to saltwater loss fall in blood Vol l b p and
filtration
reduced glomerular
Detected by volume receptors in central veins and
baro receptors in carotid arteries t aortic arch
leading to
disinhibition of renal sympathetic nerves N A release is
coupled to B l adrenocepters in the kidney to stimulate
renin production
, Pressure sensitive
granular cells also respond
fall in renal arterial pressure
directly to a localised
by
renin
Reduced CFR and
relea ing
Na to the macula densa cells causes
granular cells to secrete renin
Most angio I Angio I occurs in vascular beds
Angiotensin II
Direct Indirect
Stimulates Adrenal
AT 1 receptors cortex stimulated
in PCT T to produce aldos
Nat reabsorption tenne Stimulate
receptor in DCT
Aldosterone mechanism of action T N are absor
Steroid hormone nuclear receptor ption
Enters the cell nucleus binding to a nuclear receptor attema
m RNAlgerie expression forsynthesis of exchange1 channel
proteins activators of Nat 1kt channels and proteinsregulating
mitochondrial ATP production This results 1in T capacity in
the DCT for Nat reabsorption and KH H secretion
Vasopressin mechanism of action
Overview of RAAS
Maintain ance of volume
circulatory
and b p
Activated when volume 1 pressure
falls or glometular filtration is
reduced
Angiotensin II promotes
vas constriction
and aldosterone
vas pressin
secretion
promotes Nat and
H2O retention
Also mediates vascular and cardiac
growth structural
remodelling and enhances NA release from sympathetic
nerves
3 mechanisms of renin secretion
In response to saltwater loss fall in blood Vol l b p and
filtration
reduced glomerular
Detected by volume receptors in central veins and
baro receptors in carotid arteries t aortic arch
leading to
disinhibition of renal sympathetic nerves N A release is
coupled to B l adrenocepters in the kidney to stimulate
renin production
, Pressure sensitive
granular cells also respond
fall in renal arterial pressure
directly to a localised
by
renin
Reduced CFR and
relea ing
Na to the macula densa cells causes
granular cells to secrete renin
Most angio I Angio I occurs in vascular beds
Angiotensin II
Direct Indirect
Stimulates Adrenal
AT 1 receptors cortex stimulated
in PCT T to produce aldos
Nat reabsorption tenne Stimulate
receptor in DCT
Aldosterone mechanism of action T N are absor
Steroid hormone nuclear receptor ption
Enters the cell nucleus binding to a nuclear receptor attema
m RNAlgerie expression forsynthesis of exchange1 channel
proteins activators of Nat 1kt channels and proteinsregulating
mitochondrial ATP production This results 1in T capacity in
the DCT for Nat reabsorption and KH H secretion
Vasopressin mechanism of action
