Lecture 6 - Integration of H2O and Na+ Balance

Question 1

Is there Edema in Primary Hyperaldosteronism?

Answer 1

NO

Question 2

In Secondary Hyperaldosteronemia, Renin and Angiotensin II levels are ______ (high or low?).

Answer 2

High

Question 3

Bartter Syndrome symptoms mimic ______ poisoning. Remember there are 4 congenital mutations that result in Bartter Syndrome:

1. Na/K/Cl cotransporter mutation
2. Apical K+ channel mutation
3. Basolateral Cl- channel mutation
4. Barttin (Cl- subunit) mutation.

Which segment of the Nephron is most affected, and what basically is the result of these mutations?

Answer 3

Furosemide

The TAL is most affected, and the basic result is a decrease in the function of the Na/K/Cl cotransporter –> hence the mimicking of Furosemide poisoning symptoms!

Question 4

In Bartter Syndrome, there is an ______ (increase or decrease) in Urine Ca++ concentration. What might this result in?

Answer 4

Increase

Kidney stones

Question 5

Gitelman Syndrome symptoms mimic ______ diuretic poisoning, so that means there is a mutation in the ______ cotransporter in the _____ (early or late?) DCT.

Answer 5

Thiazide

Na / Cl cotransporter

Early DCT

Question 6

How does Urinary Ca++ concentration/excretion compare in Bartter vs Gitelman Syndrome?

Answer 6

Urine Ca++ is HIGH in Bartter and LOW or NORMAL in Gitelman

Question 7

Liddle Syndrome is caused by an ______ (activating or deactivating?) mutation of ______ channels in _____ cells.

What happens with K+ in response?

Answer 7

Activating

ENaC

Principal cells

Since ENaC is activated, which is what Aldosterone does, K+ will change in the same way it would with HyperAldosteronism –> More is EXCRETED, so plasma concentration goes DOWN.

Question 8

PsedoHYPOaldosteronism can be caused by an inactivating mutation of the ______ channel in Principal cells or the Mineralocorticoid receptor (MR).

Answer 8

ENaC

Question 9

Lack of ADH (aka Central ______ ______)

Answer 9

Central Diabetes Insipidus

Question 10

Nephrogenic Diabetes Insipidus has the same symptoms of Central, but it is caused by a congenital lack of ____ receptor or ______, or it can be acquired (i.e. from Lithium medication).

These patients will obviously NOT respond to treatment with _____, so hydration, _____ restriction, and/or ______ diuretics should be used to treat.

Answer 10

ADH receptor

Aquaporin

ADH

Na+ restriction (to prevent hypernatremia)

Thiazide diuretics

Question 11

Syndrome of Inappropriate ADH Secretion (SIADH) can be treated with ADH receptor antagonists. What were they called and which receptors do they act on?

Answer 11

“Vaptans”

Conivaptan –> nonselective V1/V2 antagonist

Tolvaptan –> V2 selective

Question 12

Diabetes Mellitus (untreated Type 1) causes Glucose to accumulate in the Nephron –> increases Urine volume –> what effect does this have on Na+ and K+ reabsorption?

Answer 12

Reabsorption DECREASES (more is excreted).