Nitric Oxide Flashcards
How is NO implicated in vasodilation?
relaxation of the smooth muscle of blood vessels
what are the three main components of blood vessels?
lumen (space where blood flows)
endothelium (cells lining lumen)
vascular smooth muscle (muscle surrounding endothelium, control size of lumen)
what is biggest symptom of angina?
reduced ability to dilate blood vessels in accordance with increased oxygen demand, drugs to target smooth muscle relaxation would be helpful i.e. NO
what is amyl nitrite?
a drug which brings about muscle relaxtion
‘poppers’
enlarges blood vessels in brain
what is glycerol trinitrate (GTN)?
highly explosive muscle relaxant
careful inhalation can releive angina symptoms
what is sodium nitropraside (SNP)?
muscle relaxant good at lowering blood pressure
but can cause cyanide poisoning
what is the action of nitric oxide synthesis?
arginine and oxygen -> citrulline and NO
what are two factors contributing to the formation of blood clots?
platelet aggregation and adhesion, NO controls these processes
what are three contributing factors to blood clot development?
aging
radical damage
lipid layer
describe the relationship between NO and cellular respiration…
respiration in mitochondria and mitochondria contain iron-sulphide clusters.
when NO binds to iron, this disrupts the clusters, resulting in non-functioning mitochondria.
this leads to necrotic cell death and associated inflammatory symptoms.
describe NO as a food preservative…
NO can be added to canned food to kill bacteria responsible for food poisoning
the nitrite nitrosates the iron-sulphate clusters of bacteria, this killing the bacteria
nitrosation also causes the pink colour of preserved meats
what is the non-specific immune system, and how is NO implicated here?
protects the body from invading pathogens using phagocytes which engulf the foreign bodies.
in immune system, NO produced by supermoxide (a radical anion) and stops system from attacking itseld
describe NO in the brain and the functions it controls…
neurotransmitter released by presynaptic neuron nad binds to postsynaptic neuron allowing an influx of ca.
glutamate is the neurotransmitter and this binds to NMDA receptor.
ca influx stimulates nNOS to convert arginine to NO.
NO diffuses back, reaching not only presynaptic neuron but many others
why do we have an NO feedback mechanism present in the brain?
diffusion of NO across synapse enhances the learning process (LTP)
what are the NO nerves associated with the peripheral NS and the associated neurotransmitter?
non-adrenergic non-cholinergic nerves
NO is neurotransmitter
