Lecture 8 - Kidney and Diuretics 2

Question 1

Define diabetes insipidus

Answer 1

Production of copious amount of diluted urine
Still feel thristy

Question 2

Define neurohypophyseal (central) DI

Answer 2

Reduced ADH secretion, normal kidney response

Question 3

What causes neurohypophyseal (central) DI?

Answer 3

Brain tumour, surgery and genetics

Question 4

Define nephrogenic DI

Answer 4

Normal ADH levels, impaired kidney reponse

Question 5

What causes nephrogenic DI?

Answer 5

Lithium poisoning, kidney diseases, genetics

Question 6

How is neurohypophyseal (central) DI treated?

Answer 6

Desmopressin (synthetic ADH)

Question 7

How is nephrogenic DI treated?

Answer 7

Thiazides - paradoxically reduce urine volume by interfering with the production of hypotonic fluid in the distil tubule

Question 8

Define the mechanism of ADH action

Answer 8

Increases the expression of aquaporin-2 on the luminal membrane

Question 9

Describe the renal effects of ADH

Answer 9

Increases water absorption
Controls the rate of urine formation

Question 10

Name the effects of aldosterone

Answer 10

Increases activation and surface expression of the luminal renal Na+ channels (ENaC)
Increases translocation of renal K+ channels (ROMK) to the luminal membrane
Increased synthesis of the basolateral Na+-K+ ATPase