Angiotensin converting enzyme inhibitor (ACEi)

Question 1

ACE inhibitors function

Answer 1

Block conversion of angiotensin I -> 2
(by blocking active site of ACE enzyme,
stops fluid retention, helps decrease BP
- decrease Na+ retention in kidneys)
- stops effects of Angiotensin II (vasoconstriction, etc.)
- also increases concentration of bradykini

Question 2

angiotensin converting enzyme (ACE)

Answer 2

If NaCl, ECF and BP is low….
converts angiotensin I to angiotensin II
- causes thirst
- increases fluid intake
- arteriolar vasoconstriction
- fluid/salt retention (high Na+ reabsorption by tubules)
- increases BP

Question 3

effects of Angiotensin 2

Answer 3

• increase sympathetic activity
• tubular Na+ and Cl- reabsorption, K+ excretion, H2O retention
• adrenal gland aldosterone secretion
• arteriolar vasoconstriction (increase BP)
• pituitary gland ADH secretion (H2O absorption)

Question 4

renin-angiotensin system

Answer 4

angiotensin released by liver, renin enzyme forms angiotensin I, passes lungs and kidneys, metabolised by ACE to Angiotensin II. Taken up by Angiotensin type 1 receptors (AT1R1)
- vasoconstriction
-Na+/H2O retention
-aldosterone release

Question 5

ACEi

Answer 5

meachnism of action:
relaxes blood vessels, reducing blood pressure
ACEi nhibitors prevent an enzyme in the body from making angiotensin 2, a substance that narrows blood vessels.

This narrowing can cause high blood pressure and forces the heart to work harder.

reducing salt and unire, meaning there is a smaller vol of blood for ur heart to pump. reduced strian on heart.

Question 6

Considerations when starting ACEi or sartans

Answer 6

Considerations when starting ACEi or sartans
- Stop K+ supplements and potassium-sparing dieuretics
- Review NSAID use
- Low dose when starting
- Check and review renal function and eletrolytes
- Work the best 4-6 weeks after starting treatment