Pumps, ATPases, Ion Channels

Question 1

Liddle’s syndrome

Answer 1

Mutation in ENaC (Na+ in, K+ out paired channel)
Impaired degradation, gain of function
Increased Na+ absorption into blood
Mimics hyperaldosteronism which would normally activate this channel
Pseudohyperaldosteronism

Question 2

Liddle’s syndrome symptoms

Answer 2

High blood pressure
Low plasma renin
Low aldosterone

Question 3

Liddle’s syndrome treatment

Answer 3

Low sodium diet

Meteoroid diuretics to block ENac

Question 4

Gitelman’s syndrome

Answer 4

Cotransporter of Na and CL not working in the distal convoluted tubule
Have increased ions in urine
Less water reabsorbed too

Question 5

Bartter’s syndrome

Answer 5

Thick ascending limb co transporter of Na+/K+/2CL- not working

Question 6

What is primary polydipsia?

Answer 6

psychogenic polydipsia

Feeling thirsty, drinking too much water

Question 7

Symptoms of primary polydipsia?

Answer 7

Symptoms include:
Excessive thirst , leading to overconsumption of water
Hyponatraemia, causing headache, muscular weakness
Too much sodium and water in urine
ADH levels fallen
Can lead to hypervolemia
Urine osmolality too low

Question 8

Which part of the nephron has no aquaporins?

Answer 8

Ascending loop of Henle

Question 9

What is renal glucoseria?

Answer 9

Glucose left in urine despite low levels of glucose in blood

Question 10

What can cause renal glucoseria?

Answer 10

Mutation of SGLT2

Question 11

Osmolality is sensed by what?

Answer 11

Hypothalamus by osmoreceptors creating thirst signal

Question 12

How does aldosterone affect DCT?

Answer 12

If too much potassium in plasma aldosterone released
Cause more ENaC to be in apical membrane/ more activated
Upregulates + activates basolateral na+/k+ pump

Question 13

What do loop diuretics cause?

Answer 13

Loss of Na+ and H2-
Increased Ca2+ loss
Hypokalemic metabolic alkalosis