Agents affecting Renin-angiotensin system (RAS) Flashcards
RAAS Inhibitors
ACE (___________)
Angiotensin (____________)
Renin (Aliskiren)
Captopril
Losartan
Is Angiotensin II (Ang II) ONLY involved in the
Renin-Angiotensin-Aldosterone System (RAAS)?
No, angiotensin II will increase the blood pressure and it works on the blood vessels and blood constriction and with heart it will make heart bigger and cause hypertrophy…not only RAAS…it can increase the release of catecholamines including norepinephrine
Angiotensin II goes to adrenal gland especially adrenal cortex to make cells release aldosterone and then it goes to the collecting duct and aldosterone stimulates the protein expression of ENac and the potassium sodium pump by that way sodium in and potassium out
Angiotensin II on the kidney
Directly – Vasoconstriction (AA, EA)
→ decreases GFR
Indirectly – Through ____________
vasoconstriction
aldosterone
How does Ang II exert its physiological effects?
Angiotensin II (Ang II) binds to the angiotensin II type 1 receptor (_______ = AGTR1).
AT1R
The hypertensive, _______, and ____________ effects of Ang II are mediated by AT1-R.
renal, hypertrophic
Do JG cells express AT1R? _______
YES
If so, what is the result of Ang II binding to AT1R?
To be, or not to be secreted, that is the question.
Angiotensin II binding to AT1R acts as _________________.
This binding (Ang II-AT1R) signals the JG cells to decrease
renin secretion. This process ensures that the RAAS doesn’t
become overactive and maintains ______________
negative feedback
homeostasis
Angiotensin II type 1 receptor (AT1R = AGTR1)
Angiotensin II – Actions on cardiovascular system
Actions on cardiovascular system
________ pressor response
________ pressor response
CV remodeling
How much the blood vessels resist the blood flow
Narrower vessels create, more resistance
rapid
slow
Peripheral Resistance
Direct Vasoconstriction → _______ in arterial BP (“Arterial vasoconstrictor”)
Increase in sympathetic discharge
Attenuates baroreceptor reductions-increasing arterial BP
Increases secretion of vasopressin (ADH) and ACTH
increase
Renal Function: Aldosterone release
Stimulates release and synthesis of aldosterone (ADLO)
Angiotensin II is the active form
Cardiovascular Structure:
Cardiac hypertrophy and remodeling
Hypertrophy increases mortality and morbidity
Stimulates migration, proliferation of vascular smooth muscle cells
Hypertrophy of cardiac myocytes
Ang II induce expression of oncogenes : c-fos, c-jun, egr-1
Alteration in the expression of FGF, TGF-β
Renin- Secreted in the_________ cells
juxtaglomerular
Angiotensinogen- Synthesized by _______
liver
Angiotensin-converting enzyme (ACE)-
Substrates: Ang I and II- Bradykinin,
Control of Renin secretion
Macula densa pathway
_________ pathway
__________receptor pathway
Baroreceptor
β-Adrenergic
Active renin release is controlled by the
___________, a renal vascular receptor,
the sympathetic nervous system, and ANG II
macula densa
Bradykinin is a substrate of ACE (angiotensin converting enzyme)
Angiotensin I is converted to angiotensin II by ACE converting enzyme
Angiotensin II is the active form and binds to AT1
