REPRO/NEPHRO BLOCK: Week 3 - Kidneys

Describe ADH action.
1. ADH binds to ( receptors) on the basolateral side of collecting duct cells
2. This causes a in the receptor, leading to the alpha subunit activating adenine cyclase
3. This stimulates production
4. This stimulates production
5. This causes expression of in the cell membrane, allowing more

What membrane transporters are found in the collecting duct?
1. (function: of Na+)
2. (function: of K+)
3. (function: of H+)

Change in kidney function in reduced tubular flow due to decreased blood flow:
1. Sensed by the
2. produce
3. Renin stimulates the renin-angiotensin system: results in the production
4. causes of the efferent arteriole
---This pressure in the glomerulus
---This hyperfiltration and thus tubular flow
5. also stimulates secretion
---This increases sodium retention via

Change in kidney function in increased tubular flow due to increased blood flow:
1. Sensed by the
2. Macula densa produces
3. causes
4. This blood flow to the kidney

Describe renal excretion of drugs via glomerular filtration protein binding.
1. Some drugs can enter the tubules via , e.g. if they are:
---
--- to plasma proteins
2. These drugs can then be in the urine
---NOTE: this cannot happen to large drugs (e.g. ) or those bound to plasma proteins

Describe renal excretion of drugs via tubular secretion independent of protein binding.
1. of drugs into the tubule from the
2. There are 2 routes of tubular secretion:
---
------Carry (i.e. alkaline), e.g.
--------->
--------->
--------->
---
------Carry , e.g.
---------> (loop diuretic)
--------->
---------> (NSAID)
3. Drugs are excreted in the urine very rapidly after secretion into the tubules
4. To prolong therapeutic effect:
---Agents can be prescribed to tubular reabsorption

Describe reabsorption dependent manipulability of drugs in the kidney.
1. After entering the tubules (either through or ), drugs are either:
--- in the urine
--- into the blood
2. Drugs are into the bloodstream together with

How can you measure creatinine clearance, used as a measure of kidney function?
1. (via 24 hour urine collection)
2.
3.
4.
5. (which take into account factors which change creatinine clearance, e.g. age, sex)

How do the kidneys excrete drugs?
1.
2. independent of protein binding
3.

What are the effects of impaired kidney function on drug metabolism/clearance?
1. Altered pharmacokinetics:
---
---
---
---
2. Altered drug effects
---
---
3. Worsening of existing renal impairment
---
---
---
4.
5.

What are the 5 main effects of impaired renal function on drug metabolism?
1.
2.
3.
4.
5.

Which factors affect the effects of renal impairment on drug metabolism?
1.
2.
3.

What are the different types of nephrotoxicity?
1. /
2.
3.
4.

How do ACE inhibitors cause nephrotoxicity?
1. Normally, if the sensed volume is reduced, causes of the to maintain glomerular filtration pressure and GFR
2. prevent the action of
3. Therefore there is no vasoconstriction of the efferent arteriole
4. Therefore, glomerular filtration pressure and GFR
---This causes kidney function impairment, i.e. nephrotoxicity

How do NSAIDs cause nephrotoxicity?
1. Normally, in reduced sensed volume, cause of in the nephron (while angiotensin II causes vasoconstriction of efferent arterioles) to maintain GFR
2. NSAIDs the action of prostaglandins
3. Therefore, there is of afferent arterioles
4. Therefore, glomerular filtration pressure and GFR
---This causes kidney function impairment, i.e. nephrotoxicity

How does gentamicin cause nephrotoxicity?
1. are needed for antibacterial activity, but this creates
2. cause , which affect the
3. Development of kidney failure depends on:
---
---
---
---

What are the 3 factors which affect the extracellular fluid volume/composition?

1.
2.
3.

What are the features of the tubular epithelium in the proximal convoluted tubule?

1.
2.
3.

What are the features of the tubular epithelium in the thin descending loop of Henle?

1.
2.

What are the features of the tubular epithelium in the thick ascending limb of the loop of Henle?

1.
2. ()

What are the features of the tubular epithelium in the collecting duct?

1.
2. ()

Describe the counter-current exchange multiplier.

1. and are transported out of the (via )
a. The is impermeable to water, so this stays in the lumen
b. This creates a concentration of electrolytes in the and

2. The around the loop of Henle flow in the direction to the nephron, so the high concentration of electrolytes is moved to surround the

3. The creates a around the
a. This allows for the reabsorption of large amounts of from the descending loop

4. This also creates a filtrate in the descending loop, which then moves on to the ascending loop – this increases reabsorption of electrolytes along the concentration gradient in the ascending loop

Describe the renin-angiotensin-aldosterone system (RAAS).

1. is secreted by the in the kidney, stimulated by:
a. Increased
b. Decreased
c.
d. levels in the DCT (sensed by the )

2. stimulates conversion of into

3. is converted to by

4. Effects of :
a. (via AII/AT1 receptors)
b. Stimulates in the nephron
c. Stimulates secretion from the adrenal cortex
d. Stimulates secretion from the posterior pituitary gland
e. Stimulates in the brain
f. Enhances adrenergic innervation
g. Stimulates cardiac and vascular hypertrophy

How does aldosterone increase sodium and fluid retention?

1. (via preformed vesicles)
2.
3.

What is the juxtaglomerular apparatus made of?

1. (in the DCT)
2. (around the afferent arteriole)
3. (in the glomerulus)