Trigger 4: NO and CVD Flashcards
in low oxygen levels
Nitrites are reduced to NO
- -> vasodilation
- -> reduces TPR reduced blood pressure
in hypoxia (CVD)
NO3 supplementation would have greatest benefit in hypoxia because reduction of NO2- to NO is undergone by deoxyhaemoglobin (without O2).
More deoxyhaemoglobin in venous circulation more NO2- reduced to NO vasodilation lowers BP
what mechanisms impair NO bioavailability
- oxidative stress
- substrat/cofactor availability
- retention by altered haemoglobin
- reduced expression and dysregulation of eNOS
- increased conc of circulating NOS inhibitors (ADMA)
name a NOS inhibitor
AMDA and Caveolin-1
oxidative stress (caused by CVD)
The imbalance between free radicals and antioxidants in your body.
what are free radicals
molecules with an uneven number of electrons (NO*) which allows them to react with other molecules.
a build of ROS….
images fatty tissue, DNA and proteins, causing inflammation and narrowing of blood vessels
ROS can also cause damage to mitochondria, which an result in apoptosis- ischameia
how does CVD cause oxidative stress (how does oxidative stress impair nitrate bioavailability?)
decreased cardiac output leads to oxygen starvation of tissue and production of free radicals.
free radicals such as superoxide can
readily react with NO to form ONOO- (peroxynitrite)- reducing bioavailability
what causes a reduction in NOS
increased expression of Caveolin-1
Caveolin-1
Inhibits eNOS by anchoring it to the membrane. In CVD there is increased expression of Caveolin-1, therefore less NO production
name 6 CVD factors
- Increased expression of Caveolin-1
- Increased inhibition of eNOS
- Less NO produced
- Decreased NO bioavailability
- Reduction in NO-mediated vasodilation
- Endothelial dysfunction which promoted atherosclerosis (with hyperlipidaemia
ischameica caused by CVD causes
increased turnoverr of ADMA
increased turnover of AMDa mean
there are less activated NOS- less NO produced
what other causes increases in AMDA
renal impairment-
