Regulation of Potassium Balance

Question 1

Effect of Epinephrine on K+

Answer 1

Decrease in serum potassium by increasing uptake into cells

Question 2

Effect of Insulin on K+

Answer 2

Decrease in serum potassium by increasing Na-K ATPase activity

Question 3

What hormone can be used to treat hyperkalemia?

Answer 3

Insulin

Question 4

Effect of Aldosterone on K+

Answer 4

Increase potassium secretion

Question 5

What three factors enhance the cellular uptake of potassium?

Answer 5

Insulin
Alkalosis
B-catecholamines

Question 6

What three factors cause decreased cellular uptake of K+

Answer 6

A-catecholamines
Acidosis
Cell damages

Question 7

What two factors enhance cellular efflux?

Answer 7

Hyperosmolarity

Strenous exercise

Question 8

Formula for filtered load?

Answer 8

(GFR)(plasma concentration)(% filterability)

Question 9

What drives the reabsorption of K+ in the proximal tubule?

Answer 9

Positive TEPD

Question 10

Where does Medullary recycling occur?

Answer 10

Potassium is reabsorbed in the Medullary collecting duct, and then secreted into the loop of henle

Question 11

What’s the goal of medullary recycling?

Answer 11

Increase in medullary K+ will increase the activity of the NKCl2 receptor on the TAL –> allows more Na to be delivered to the distal tubule

Question 12

What cells in the distal tubule allow for K+ secretion?

Answer 12

beta-intercalated cells

principle cells

Question 13

What cells in the distal tubule allow for K+ reabsorption?

Answer 13

alpha-intercalated cells

Question 14

What increases secretion of K+ in the distal tubule?

Answer 14

Increase in ECF concentration
Aldosterone
Increase in tubular flow rate

Question 15

What transporters are found on the apical side of principle cells, and are responsible for secretion of K+?

Answer 15

BK and ROMK transporters

Question 16

What 5 factors regulate K+ secretion?

Answer 16

NaK ATPase pump on the basolateral membrane
Reduced back leakage of K+
Increase in K+ channels
Increase in aldosterone
Increased Distal tubular flow rate

Question 17

What does acute alkalemia do to K+?

Answer 17

Leads to hypokalemia

(Increased K+ secretion)

(K is Low)

Question 18

What does acute acidemia do to K+?

Answer 18

Hyperkalemia

decreased K+ secretion

Question 19

What does chronic acidosis do to K+?

Answer 19

Stimulate K+ secretion

Question 20

What effect do diuretics have on K?

Answer 20

Promote K+ secretion by increasing Na+ reabsorption