Nitrate

Question 1

How much nitrate generated daily from NO oxidation?

Answer 1

1mmol

Question 2

How much daily from typical western diet?

Answer 2

1-2mmol

Question 3

Benefits of organic nitrate supplementation

Answer 3

Rapid onset
Fast absorption through mucosal membrane
Lowers systemic BO
inhibits platelet aggregation

Question 4

Limitations of organic nitrate supplementation

Answer 4

Can develop tolerance
Can cause endothelial dysfunction
Variable bioavailability when taken orally
Extensive 1st pass metabolism

Question 5

What factors effect NO bioavilability

Answer 5

Oxidative stress (excess ROS impairs NO reduction)
Substrate/co-factor availability
Increased expression of intracellular eNOS inhibitors
Increased circulation of NOS inhibitors
retention by altered haemoglobin

Question 6

What effect does calveolin-1 have

Answer 6

Intracellular e-NOS inhbitor

Question 7

What is ADMA

Answer 7

NOS inhibitor

Question 8

What does oxyhaemoglobin do

Answer 8

Acts as a nitrate reductase

Question 9

What is NO generated from endogenously

Answer 9

L-arginine

Question 10

What enzymes catalyse endogenous NO production

Answer 10

eNOS (endothelial)
nNOS (neuronal)
iNOS (inducible)

Question 11

What are NOS enzymes dependent on

Answer 11

calmodulin

Question 12

What do NOS use as an electron donor

Answer 12

NADPH

Question 13

How do NOS convert arginine to NOS

Answer 13

5 cofactors for 5 electron oxidation of arginine to NO

Stoichiometric production of citrulline

Question 14

What are nitrothiols

Answer 14

Storage molecules for NO, broken down to form NO

Question 15

Where is dietary nitrate absorbed

Answer 15

GI tract

Question 16

How much absorbed nitrate is in salivary glands

Answer 16

25%

Question 17

What reduces dietary nitrate to nitrate and where

Answer 17

Facultative anaerobes

Dorsum of tongue

Question 18

What happens to smallowed nitrite not absorbed

Answer 18

Acid reduction to NO in stomach

Question 19

How much dietary nitrate is lost via urine

Answer 19

60% in first 48 hours

Question 20

Action of Nitrate

Answer 20

Decreases BP
Reduces platelet aggregation
Reduced oxygen cost
Increased cerebral blood flow
Increased muscle contractility

Question 21

Action of Nitric Oxide

Answer 21

Regulates vascular tone (vessel dilation and contraction)
Keeps stomach mucus thick
Neurotransmitter
Higher effect in veins than arteries

Question 22

Symbol for nitrite

Answer 22

NO2-

Question 23

Symbol for nitrate

Answer 23

NO3-