Renal Pharma and Drugs

Question 1

Function of Aliskiren.

Answer 1

Blocks enzymatic activity of Renin

Question 2

Function of Amiloride

Answer 2

Na+ Channel Blocker;
Competitive inhibitor of ENaC; Decreases driving force of K+ secretion (K+ sparing diuretic);
Also stimulates Ca2+ reabsorption

Question 3

Function of Biguanides.

Name one example.

Answer 3

Reduces blood sugar by inhibiting liver gluconeogenesis;
Enhances insulin receptor signaling;
Ex: Metformin

Question 4

Name 2 mineralocorticoid receptor antagonists and their function.

Answer 4

Eplerenone and Spironolactone;
Aldosterone blockers that lower Na+ retention;
Calcium-sparing diuretic drugs

Question 5

Function of Sulfonylureas.

Answer 5

Targets pancreatic Beta-cells;
Insulin secretagogue (promotes secretion of insulin)

Question 6

Function of Thiazolidenediones

Answer 6

Insulin sensitive agent - enhance the action of insulin in target cells

Question 7

Function of Tolvaptan.

What can it be used to treat

Answer 7

Vasopressin V2 receptor antagonist;

Can be used to treat hyponatremia by increasing plasma Na+

Question 8

What are the purposes of taking insulin?

What might occur if a type I diabetic stops his regimen?

Answer 8

Increase cellular uptake of K+ and glucose, in order to reduce blood sugar and lower plasma K+;
If a DM I patient abruptly stops that can result in severe hyperglycemia, ketoacidosis and hyperkalemia.

Question 9

What effect does a Loop Diuretic have on the Thick Ascending Loop?

Answer 9

Inhibits NKCC pump, thus reducing reabsorption of ions Na+, K+, Cl-. Water is pulled out towards the urine as part of pressure natriuresis. Ca++ and K+ wasting occurs

Question 10

This drug is a potent diuretic that blocks NCC in the distal convoluted tubule to stimulate Ca++ reabsorption and K+ wasting. Not recommended for someone with hypokalemia.

Answer 10

HCTZ (Thiazide type drug)

Question 11

This type of drug works by blocking NKCC thus promoting Ca++ wasting. It’s not recommended for someone with hypocalcemia.

Answer 11

Furosemide (Loop Diuretic)

Question 12

What hormone is secreted when there is high RAP (atrial distension)? What effect does it have on GFR and where does it act in the nephron?

Answer 12

ANP is secreted with high RAP. It increases GFR and increases Na+ filtration, by acting on the afferent arteriole and DCT.

Question 13

When Angiotensin II (ATII) binds to AT1-receptor, what effects does it have on GFR, aldosterone, Na+ and renin? Where does it act in the nephron?

Answer 13

ATII binding to AT1-receptor elicits increased GFR, increased aldosterone secretion, increased Na+ reabsorption and decreased Renin release. It acts on the PCT, TAL and efferent arteriole.

Question 14

What hormone is secreted in the presence of low plasma Ca++? What effects does it have and where does it act in the nephron?

Answer 14

PTH is secreted when there are low Ca++ or high phosphate levels in the plasma. When acting on the PCT it increases Ca++ reabsorption, reduces phosphate reabsorption and increases Calcitriol production. It indirectly increases Ca++ and phosphate absorption in the gut via activated Vitamin D.

Question 15

Aldosterone is secreted in response to ___ BP and ___ plasma K+. It acts on the DCT and CCT to ____ Na+ reabsorption and ____ plasma K+/H+.

Answer 15

Aldosterone is released in low BP and elevated plasma K+ levels. Effects include increased Na+ reabsorption and decreased K+/H+ via secretion.

Question 16

What hormone is secreted in the presence of high plasma osmolarity and low BP? Where does it act on the nephron and what effects does it elicit?

Answer 16

ADH (vasopressin) binds to V2R receptors to increase expression aquaporins in the CCT that enables water reabsorption. This causes dilution of hyper-osmolar plasma.