RAAS

Question 1

This system invelved in pathophysiology of :

Answer 1

HTN, CHF, MI, diabetic nephropathy

Question 2

It is a protese synthesized and stored in juxtaglomerular apparatus (JGA) of nephron that lie in the wall of the afferent arterioles

Answer 2

Renin

Question 3

JGA is innervated by :

Answer 3

nor-adrenergic neurons

Question 4

Control of renin by 3 pathways:

Answer 4

Two acting locally:1.macula densa and intra-renal baroreceptor
And one is CNS mediated by NE release from renal nor-adrenergic nerve.

Question 5

Macula densa pathway

Answer 5

NaCl flux across the M.D inhibits renin release, and vise versa
Regulation of this pathway is more dependent on the luminal con. Of Na+ and Cl
PG and adenosin mediate this pathway
PG ++ renin release
Adenosin – renin release

Question 6

Intra renal baroreceptor pathway:

Answer 6

++ pressure in the preglomerular vessele – renin release

— pressure in the preglomerular vessels stimulates renin release

Question 7

CNS mediated pathway

Answer 7

By NE release from renal NA nerve

Stimulation of beta receptors on JGC increases renin secretion

Question 8

Factors ++ renin release:

Answer 8

Loop diuretic, vasodilators, beta agonist, alpha antagonist
phosphodiesterase inhibitors (-- c-AMP in JGC)

Question 9

Factors – renin release:

Answer 9

NSAIDs》–PG
Beta blockers
Centrally acting sympatholytic drugs

Question 10

Direct renin inhibitor:

Answer 10

Aliskiren

Question 11

Mechanism of action of aliskiren:

Answer 11

It blocks the conversion of prorenin to renin

Question 12

Angiotensinogen synthesized in :

Answer 12

In The Live

Question 13

Factors that + Angiotensinogen sythesis:

Answer 13

Inflammation, insulin, estrogen, glucocorticoid, thyroid h, pregnancy and AgII

Question 14

ACEs:

Answer 14

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Question 15

Angiotensinase:

Answer 15

It metabolises AgII
the product has V.D effect
Does not hydrolyse bradykinin
It is not inhibited by ACE I

Question 16

Angiotensin R

Answer 16

GPCR(q)

There is 2 subtypes

Question 17

AT1-R:

Answer 17

+ PLC》IP3,DAG》S.M. contraction
Vascular and cardiac growth mediated by other pathway through tyrosine kinase pathway》+ transcription of some specifi genes
It is associated with HTN, hypertrophic cardiomyopathy, coronary artery disease

Question 18

Most of AgII action is mediated via this receptor:

Answer 18

AT1-R

Question 19

AT2-R:

Answer 19

Distributed widely in fetal tissue
Antiproliferative
Antihypertensive
Vasodilator effect through NO dependent mechanism, may involve bradykinin B2-R

Question 20

Pharmacological effects of AgII :

Answer 20

TPR: direct V.C, +NE release from sympathetic outflow, -NE reuptake into nerve terminal
CNS: + ABP by + symp out flow
+ ADH, stimulation of thirst centre and increases water intake

Question 21

AgII effects on adrenal cortex and kidney :

Answer 21

Agii acts on the Zona glomerulosa and causes release of aldosterol
Kidney : Renal VC》-RBF》-GFR
\+ proximal tubular Na+ reabsorbtion
- renin secretion
Enhance renal sympathetic tone
Facilitate renal adrenergic transmission

Question 22

Effects of Aldosterol

Answer 22

It acts on the principal cells (p-cells) which are present at last part of DCT and collecting duct
It causes Na+ retension, k+, H+ excretion
So increases BP

Question 23

AgII Altered CV structure

Answer 23

Stimulation migration, proliferation, hypertrophy of vascular S.M, cardiac myocyte, + extracellular matrix prodoction
Leading to CV hypertrophy and morphological changes》remodelling

Question 24

Cardiac remodeling

Answer 24

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