Nitrates Flashcards
What are the 2 Nitric oxide pathways
L-arginine pathway
Nitrate reverse pathway
how does the L-arginine pathway work
L-arginine + 02 + NADPH (w/ nitric oxide synthase) = nitric oxide
what happens after nitric oxide is produced
turned into nitrite and then nitrate
how does the reverse nitric oxide pathway work?
nitrate to nitrite then to nitric oxide
what does endothelia nitric oxide do?
allows blood vessel relaxation / vasodilation
what does nitric oxide do to smooth muscle?
causes it contract
what are the 3 types of NOS
neuronal, endothelial, inducible
how does NO reduce calcium in muscle
- diffuses into muscle
- activates guanylyl cyclase
- ^ cyclic guanosine monophosphate
- activates protein kinase = decrease Ca2
4 ways decreased Ca is achieved in the muscle
- inhibition of voltage gated channels
- activation of plasma membrane Ca ATPase
- inhibition of inositol triphosphate receptors
- activation of sarcoplasmic calcium ATPase
How does age effect nitric oxide production
it is impaired but the effects can be decreased with a good diet and exercise
what does arginine supplementation do?
lowers systolic & diastolic blood pressure
which foods are high in nitrates/ nitrites?
(depends on growth and storage conditions
green leaf veg, beetroots, spinach ect
drinking water
why are beetroot shots used for NO research
- high dose
- easy to measure NO levels in it
- low volume
- nitrate depleted bottles used in double blind placebo trails
what is the nitrate journey?
25% recycled to saliva then converted into nitrite (20%)
5% reaches stomach - NO
75% excreted
how is nitrate converted to nitrite by the mouth
reduced by oral facultative bacteria
what happens to nitrite in the stomach/SI
some is reabsorbed & converted to nitric oxide into systemic circulation
which region eats more nitrate on average
EU > NA
which diet has the most nitrate
DASH - dietary approach to stop hypertension
WHO guidelines for nitrate / nitrite
nitrate - 3.7 mg/kg
nitrite - 0.07 mg/kg
why are their guidelines for nitrates/nitrites
links between them and cancer
nitrate and cardiovascular disease link
low nitrate intake = higher chance of having cardiovascular disease when aging
what is flow mediated dilation?
cardiovascular health test
cuff blown up and then released dramatically increasing blow flow (shear stress) endothelium will release vasodilators and NO = healthy arteries
how does beetroot juice effect exercise performance?
same power output can be produce while using less oxygen (more efficient)
(delay reaching vo2 max)
why might nitrate supplementation be less effect in elite atheletes?
higher baseline plasma
higher NOS activity
better muscle oxygenation
what are the mechanisms of nitrate increasing performance?
augmented muscle blood flow
enhanced mitochondrial efficiency
reduced ATP cost of muscle force production
