Diuretics: Ch. 2.1- Acetazolamide, mannitol

Question 1

By the end of the proximal convoluted tubule, the concentration of ______ is decreased.

Answer 1

most solutes

Question 2

By how much is the concentration of filtered sodium decreased by the end of the proximal convoluted tubule?

Answer 2

66%

Question 3

Carbonic anhydrase inhibitors, such as ______, cause sodium and bicarb to stay in the lumen leading to urine alkalization.

Answer 3

acetazolamide

Question 4

The buildup of bicarb in the tubule _____ the pH of the urine.

Answer 4

increases

Question 5

What does water always follow?

Answer 5

Na+

Question 6

What is reabsorbed at the end of the proximal convoluted tubule?

Answer 6

bicarb

Question 7

The H2O + CO2 produced by carbonic anhydrase (H2CO3) diffuse into the ______.

Answer 7

intracellular space

Question 8

Where are Na+/K+ ATPase pumps located?

Answer 8

on the basolateral membrane

Question 9

_____, such as acetazolamide, cause sodium and bicarb to stay in the lumen leading to urine alkalization.

Answer 9

Carbonic anhydrase inhibitors

Question 10

What are the SEs of acetazolamide?

Answer 10

• K+ wasting (hypokalemia)
• type 2 renal tubular acidosis
• increased calcium phosphate stone formation
• they’re sulfa drugs (= hypersensitivity rxns)

Question 11

Cue:

• mom at the vending machine taking away peanuts and giving her son a banana

Answer 11

• vending machine = Na+/K+ ATPase (pump) on the basolateral membrane
• taking away peanuts = taking away Na+
• giving banana = giving K+
• *** The Na+/K+ ATPase pumps 3 Na+ out and 2 K+ in.

Question 12

Cue:

• helmets labeled “H+”

Answer 12

protons

Question 13

Cue:

• peanuts

Answer 13

salt (Na+)

Question 14

Cue:

• 3 batteries powering a banana vending machine

Answer 14

• 3 batteries = 3 ATPs
• banana = K+
• vending machine = Na+/K+ ATPase (pump) on the basolateral membrane

Question 15

What is the function of the proximal convoluted tubule?

Answer 15

reabsorption

Question 16

Cue:

• pro-cart track

Answer 16

proximal convoluted tubule

Question 17

Where in the nephron does mannitol exert its effects?

Answer 17

• in the proximal convoluted tubule
• in the descending limb of the Loop of Henle

Question 18

What is resorbed at the proximal convoluted tubule?

Answer 18

• electrolytes (Na+, Cl-, K+)
• organic solutes (glucose, amino acids)

Question 19

Carbonic acid (H2CO3) –> ____ + ____

Answer 19

H2O + CO2

Question 20

By how much is the concentration of bicarb increased at the end of the proximal convoluted tubule?

Answer 20

85%

Question 21

Cue:

• batteries

Answer 21

ATP

Question 22

H+ + HCO3- = ______

Answer 22

carbonic acid (H2CO3)

Question 23

Is acetazolamide K+ sparing or wasting? Why?

Answer 23

• wasting
• bc Na+ is spared

Question 24

Why is bicarb reabsorbed in the proximal convoluted tubule?

Answer 24

to maintain acid-base status

Question 25

What is the normal intracellular concentration of Na+ in the renal ? Why?

Answer 25

* low * to allow for increased renal tubule absorption

Question 26

What kind of acid/base change do carbonic anhydrase inhibitors, such as acetazolamide, cause?

Answer 26

a normal anion gap metabolic acidosis

Question 27

Carbonic anhydrase inhibitors, such as acetazolamide, cause sodium and bicarb to stay in the lumen leading to \_\_\_\_\_.

Answer 27

urine alkalization

Question 28

How does mannitol work in the kidney?

Answer 28

it remains in the lumen --\> water is pulled into the lumen towards it (osmotic diuresis)

Question 29

Cue: * track worker standing at the edge of the yellow/gray tracks handing out peanuts to the gray side and letting H+ helmets back into the yellow side

Answer 29

* track worker = Na+/H+ exchanger * peanuts = Na+ * H+ helmets = protons * \*\*\* Na+/H+ exchanger is located on the apical membrane

Question 30

By how much is the concentration of filtered glucose and amino acids decreased by the end of the proximal convoluted tubule?

Answer 30

all

Question 31

Cue: * bananas

Answer 31

potassium (K+)

Question 32

Which diuretics exert their effects at the proximal convoluted tubule?

Answer 32

* acetazolamide * mannitol

Question 33

What is the function of the Na+/H+ exchanger?

Answer 33

allows bicarb reabsorption at the proximal convoluted tubule

Question 34

At which site in the nephron do acetazolamide and mannitol exert their effects?

Answer 34

at the proximal convoluted tubule

Question 35

What is mannitol? What is it used to treat?

Answer 35

* an osmotic diuretic * tx for: * elevated intracranial pressure * elevated intraocular pressure/glaucoma

Question 36

Excessive bicarb depletion leads to \_\_\_\_\_.

Answer 36

excessive Na+/Cl- reabsorption

Question 37

The Na+/K+ ATPase pumps ____ out and _____ in.

Answer 37

* 3 Na+ out * 2 K+ in

Question 38

Carbonic anhydrase inhibitors, such as acetazolamide, cause ______ to stay in the lumen leading to urine alkalization.

Answer 38

sodium and bicarb

Question 39

What are the s/s of acute mountain sickness?

Answer 39

* weakness * insomnia * dizziness * HA * nausea * pulm/cerebral edema

Question 40

By how much is the concentration of potassium decreased by the end of the proximal convoluted tubule?

Answer 40

65%

Question 41

What are carbonic anhydrase inhibitors used for? Name 1 example.

Answer 41

* tx for: * glaucoma (decrease aqueous humor production) * idiopathic intracranial HNT aka pseudotumor cerebri (decreased CSF production) * tx and prevention of: * acute mountain sickness * gout * uric acid stones/cystenuria * one ex: acetazolamide

Question 42

Cue: * yellow and gray race tracks separated by a divider

Answer 42

* yellow = lumen of the renal tubule * gray = intracellular compartment of the tubule epi cells (next to the interstitium) * divider = basolateral membrane where Na+/K+ ATPases are located

Question 43

Cue: * biCARb race car on the yellow track

Answer 43

* bicarb = HCO3- * yellow track = lumen of the prox. convoluted tubule (PCT)

Question 44

How does acetazolamide work?

Answer 44

it inhibits carbonic anhydrase --\> no bicarb reabsorption

Question 45

This drug inhibits carbonic anhydrase --\> no bicarb reabsorption.

Answer 45

acetazolamide

Question 46

What are the SEs of mannitol?

Answer 46

* pulmonary edema * heart failure exacerbation * hypernatremia --\> severe dehydration