Pbd Final Exam Review- Ras

Front 1

What are the two major effects of the renin-angiotensin system in the body?

Back 1

Maintains blood pressure
Salt and water balance

Front 2

What are two other roles the renin-angiotensin system plays in?

Back 2

Vasoconstriction of vessels
Inflammation

Front 3

The RAS is composed of?

Back 3

systemic (vascular) and local tissue system

Front 4

T/F The RAS is involved in short term regulation of blood pressure only.

Back 4

False- involved in short and long term regulation of blood pressure

Front 5

Is the rate limiting factor in the activity of the systemic renin angiotensin system

Back 5

Angiotensinogen

Front 6

Angiotensinogen is primarily synthesized in the _____

Back 6

hepatocytes found in the liver

Front 7

In adipose tissue angiotensinogen mRNA is upregulated by what?

Back 7

Insulin

Front 8

In the hepatocytes angiotensinogen mRNA is upregulated by what?

Back 8

Estrogen

Front 9

Angiotensinogen is cleaved by the what enzyme?

Back 9

Renin

Front 10

Angiotensinogen is cleaved into what?

Back 10

Angiotensin I

Front 11

Synthesis of angiotensinogen can be stimulated by what?

Back 11

Inflammation
Angiotensin II

Front 12

Angiotensin II may exert what sort of feedback regulation via what sort of receptor.

Back 12

Positive Feedback
AT1 receptor

Front 13

Several lines of investigation suggest that angiotensinogen contributes to what phenotype?

Back 13

Hypertensive

Front 14

Angiotensinogen is the protein from which angiotensins are formed by what type of reactions?

Back 14

Proteolytic Cleavage reactions

Front 15

Is a highly substrate-and species-specific aspartyl protease enzyme

Back 15

Renin

Front 16

How many amino acids are lost in the reaction involving renin that created angiotensin I from angiotensinogen

Back 16

four
14aa Angiotensinogen to a 10aa Ang I

Front 17

What cells are the systemic source for renin synthesis, storage and release?

Back 17

Juxtaglomerular (JG) cells

Front 18

What is the initial step in the synthesis of renin?

Back 18

The formation of the pre-pro-renin by renin mRNA

Front 19

How many amino acids make up the "pre" portion of pre-pro-renin?

Back 19

23 aa

Front 20

How many amino acids make up the "pro" portion of pre-pro-renin?

Back 20

43 aa

Front 21

Where in the cell is the "pro" portion of pre-pro-renin cleaved to renin?

Back 21

in the golgi apparatus

Front 22

The active renin molecule has how much energy?

Back 22

40,000 Daltons

Front 23

What enzyme mediates the cleavage and activation of renin?

Back 23

Cathepsin B

Front 24

Renin is excreted from the cell into the blood stream by what action?

Back 24

exocytosis

Front 25

What are the three regulatory pathways of the JG cells that control the secretion of renin?

Back 25

1. Macula densa pathway
2. Intrarenal baroreceptor pathway
3. Beta-adrenergic receptor pathway

Front 26

How does the regulatory macula densa pathway work?

Back 26

They monitor sodium levels.
Low sodium level is the signal that initiates a series of steps that ultimately stimulates renin release

Front 27

How does renin effect sodium levels?

Back 27

Renin helps to create angiotensin which interacts with aldosteron which causes sodium uptake in the body

Front 28

The macula densa pathway is like more of what type of system for regulating renin release?

Back 28

chronic adaptive system

Front 29

What are two other molecules activated by the macula densa pathway that stimulate the release of renin?

Back 29

PGE2 and Cox 2 enzyme

Front 30

Dietary sodium restriction results in an upregulation of what?

Back 30

The inducible Cox 2 expression

Front 31

What substance inhibits renin release?

Back 31

Adenosine

Front 32

Where are the renal baroreceptors located?

Back 32

in the afferent arterioles

Front 33

How do baroreceptors effect renin secretion?

Back 33

They stimulate renin secretion in response to reduced renal perfusion pressure and attenuates renin secretion as renal perfusion is elevated.

Front 34

What pathway is the most powerful regulator of renin release?

Back 34

The Baroreceptor Pathway

Front 35

The JG cells are directly innervated by what nerves?

Back 35

Sympathetic nerves

Front 36

Direct stimulation of the sympathetic nerves innervating the JG cells causes what?

Back 36

An increase in renin release

Front 37

The Beta-adrenergic receptor pathway is what type of pathway?

Back 37

Acute pathway

Front 38

Which pathway provides rapid activation of the RAS which is provoked by such stimuli as stress and posture?

Back 38

Beta-adrenergic Receptor Pathway

Front 39

What sort of physiological network are the three renin regulatory systems in?

Back 39

Short-loop negative feedback system

Long-Loop negative feedback

Front 40

Increase in renin secretion will result in what?

Back 40

an increase in Ang II

Front 41

Ang II stimulates what on the JG cells?

Back 41

AT1R

Front 42

Stimulated AT1R on the JG cells does what?

Back 42

inhibits renin release

Front 43

Ang II increases what via AT1R?

Back 43

Blood Pressure

Front 44

How does an increase in blood pressure inhibit renin release?

Back 44

Throught the Baroreceptor pathway

Front 45

cAMP it he primary second messenger for what in the renin regulatory loops?

Back 45

Beta-adrenergic and PGE

Front 46

An increase in cAMP causes what in the renin regulatory loops?

Back 46

Increase in Renin

Front 47

Renin release is inhibited by an increase in what intracellular ion?

Back 47

Ca ++

Front 48

In the renin regulatory loop cGMP acts as what?

Back 48

An inhibitory second messenger

Front 49

How would factors that stimulate cGMP affect renin release?

Back 49

Inhibit renin release

Front 50

Loop Diuretics do what in the renin pathways?

Back 50

Block NaCl reabsorption which then stimulates the macula densa pathway to secrete more renin

Front 51

How do NSAIDS affect renin release?

Back 51

They inhibit PG which decreased renin release

Front 52

How do ACE inhibitors and AT1R blockers affect renin release?

Back 52

They interrupt the feedback systems which then causes an increase in renin release

Front 53

How do Beta-adrenergic blockers and central acting sympatholytic drugs affect renin release?

Back 53

They inhibit the adrenergic pathway and therefore decrease renin release

Front 54

The macula densa chemoreceptors act as what type of regulator in the renin release system?

Back 54

Long term regulator

Front 55

The Juxaglomerular baroreceptors act as what type of regulator in the renin release system?

Back 55

Most powerful regulator

Front 56

The Sympathetic stimulation act as what type of regulator in the renin release system?

Back 56

Most rapid regulator

Front 57

An ubiquitous enzyme, found in the plasma and is a membrane-bound extoenzyme predominately on endothelial and epithelial cells.

Back 57

Angiotensin Converting Enzyme (ACE)

Front 58

What is the major physiological function of ACE?

Back 58

Convert Ang 1 to Ang II

Front 59

ACE inactivates what regulator of blood pressure?

Back 59

Bradykinins (which act as vasodialtors reducing pressure while Angs increase pressure)

Front 60

What enzyme acts as the angiotenisn converter?

Back 60

Chymase

Front 61

Endothelial ACE contains how many inhibitory binding sites per molecule?

Back 61

Two

Front 62

Homozygous individuals for the insertion polymorphism ACE gene have what?

Back 62

Lower levels of ACE in the plasma

Front 63

Homozygous individuals with the deletion polymorphism (DD) have what?

Back 63

Double the circulating levels of ACE

Front 64

ACE is found on endothelial cells especially where in the body?

Back 64

lungs
retina
brain

Front 65

Ace is found on epithelial cells especially where in the body?

Back 65

kidney and gut

Front 66

ACE2 is expressed in the endothelial cells located where in the body?

Back 66

heart
testis
kidney

Front 67

ACE2 catalyzes the formation of what vasodilator molecule from both Ang I and Ang II?

Back 67

Ang I-7

Front 68

ACE2 may act as what of Ang II action?

Back 68

An antagonist

Front 69

How is ACE 2 affected by ACE inhibitors?

Back 69

It is insensitive to ACE inhibitors

Front 70

ACE 2 levels increase in what two disease states?

Back 70

Hypertension
Heart Failure

Front 71

What are the two specific receptors of Ang II?

Back 71

AT1 and AT2

Front 72

AT1 and AT2 are what type of proteins?

Back 72

Members of G protein coupled receptor family with 7 transmembrane regions

Front 73

What mediates most of the biological effects of AngII?

Back 73

AT1R

Front 74

Glucocorticoids and Insulin do what to the number of AT1R receptors?

Back 74

Increase the number of receptors

Front 75

Miineralocorticoids and Estrogens do what to the number of AT1R receptors?

Back 75

Decrease the number of receptors

Front 76

What receptor is widely distributed in the fetal tissues?

Back 76

AT2R

Front 77

How does AT2R interact with AngII on AT1 receptors?

Back 77

In opposition to

Front 78

What receptor is re-expressed in times of injury?

Back 78

AT2R

Front 79

Inhibition of ACE initially causes what?

Back 79

Increase in Ang I concentration
Decrease in Ang II concentration
Decrease in Aldosterone concentration

Front 80

Why could plasma levels of Ang II not remain suppressed during chronic therapy of ACEI?

Back 80

Incomplete block of the enzyme

Increase in Ang I may exceed inhibitory capacity of ACEI

Another rout for Ang II formation through Chymase

Front 81

ACE inhibition blocks the degradation of what which inhibits what which can cause what?

Back 81

Ang I-7
Ang II action
Allows for vasodilation and antiproliferation

Front 82

ACE inhibition increase what which also can what?

Back 82

Bradykinin
Vasodilate

Front 83

ACE inhibition increase what levels?

Back 83

ACE 2 and Ang I-7

Front 84

Local RAS systems are considered part of what system?

Back 84

Paracrine/autocrine system

Front 85

Locally formed angiotensins can act as what?

Back 85

growth factors
neurotransmitters
smooth muscle constrictors

Front 86

Weight loss decreases what in the angiotensin cycle?

Back 86

ACE

Front 87

What are the two major roles of Ang II?

Back 87

Regulation of blood pressure
Sodium homeostasis

Front 88

Ang II directly causes what primarily in the precapillary arterioles?

Back 88

Vasoconstriction

Front 89

How does Ang II enhance peripheral noradrenergic neutoransmission?

Back 89

It augments NE release
Inhibits uptake of NE
Enhances vascular response to NE

Front 90

What are Ang II effects on the central nervous system?

Back 90

increases sympathetic outflow

Increases arterial pressure through baroreceptor mediated sympathetic discharge

Causes dipogenic effect (water uptake)

Enhances the release of ADH

Front 91

What hormones does Ang II stimulate to be released and form where?

Back 91

Catecholamines from the medulla
Aldosterone form the cortex

Front 92

Ang II stimulates what in vascular smooth muscle (VSM)

Back 92

Hypertrophy
Vasoconstriction
Mitogenesis

Front 93

RAS plays a role in what disease state?

Back 93

Atherosclerosis

Front 94

RAS is required for the development of what?

Back 94

normal renal function

Front 95

RAS generates what?

Back 95

Reactive oxygen species

Front 96

RAS leads to what in the endothelial?

Back 96

endothelial dysfunction

Front 97

Ang II stimulates what in a pro-thrombotic effect?

Back 97

PAI-1 (plasminogen activator inhibitor)

Front 98

Angiotensin plays an important role in what process?

Back 98

Hemorrhaging

Front 99

Name the pro-inflammatory effects Ang II has.

Back 99

Act as a Cytokine (growth promoter and pro-inflammatory modulator)

Increase vascular permeability

Participates in the recruitment of cells

Regulates the expression of adhesion molecules and chemokines

Participate in tissue repair

Front 100

Where in the adrenal cortex is aldosterone produced?

Back 100

zona glomerulosa

Front 101

Secretion of aldosterone is regulated primarily by what?

Back 101

Ang II and potassium

Front 102

Aldosterone acts on renal and other epithelia to do what?

Back 102

Enhance sodium reabsorption and increase the excretion of potassium and hydrogen ions