Theme C lecture 9 Flashcards
What does low birth weight do to BP?
Low birth weight increases chance of developing hypertension late in life.
Which part of the blood vessel respond to vasocinstrictors and vasodilators?
Smooth muscle
Which part of the blood vessel produce vasocinstrictors and vasodilators?
endothelial cells
What are the cell types that can be influenced by vascular dysfunction?
Smooth muscle
Endothelium
Extracellular matrix
Nerves
Where can smooth muscle be found?
In the tunica media layer
What is the layer in which the extracellular matrix of blood vessels can be found?
tunica adventitia
How do endothelial cells react to vasodilators?
3 pathways to relaxation of blood vessels:
Nitric oxide production (eNOS)
Prostacyclin (PGI2 production)
Ion channels causing hyperpolarisation by opening potassium channels.
How does nitric oxide production cause vasodilation?
NO binds to guanylate cyclase which increases cyclic gmp causing vascular smooth muscle to relax.
How does PGI2 cause vasodilation?
It converts ATP to cAMP which causes smooth muscle to relax
What protein causes PGI2 production?
COX
How do ion channels cause smooth muscle relaxation in blood vessels?
Potassium enters vascular smooth muscle making it hyperpolarised and as a result relaxation occurs.
Why is production of cAMP and cGMP a cause of vasodilation?
They cause hyperpolarisation and relaxation of blood vessels
What is the effect of vessel size on the kind of vasodilators they use?
The bigger the vessel the more reliance on NO and the smaller vessels use all 3 pathways.
What effect does small birth weight have on blood flow through blood vessels?
Being born small has negative consequences on blood flow.
What happens to acetylcholine response in adults born small?
Response to acetylcholine is impaired in adults born small.
What causes the reduced vasodilation effect in adults born small?
A study conducted in 9 year old children used nitroglycerine and nitric oxide to see whether the reduced blood vessel dilation was due to smooth muscle or endothelial tissue. It was discovered that the effect is due to reduced endothelial function
What is wire myography?
A technique used to measure the ability of blood vessels to constrict/dilate to a particular drug. It measures both endothelial function and smooth muscle function.
What happens to blood pressure of offspring with mothers that have 30% reduction in their diet?
If the mother’s diet is restricted by 30% it has an impact on the blood pressure of their offspring. This effect happens earlier in males than females.
What is the effect of birth weight on sensitivity to thromboxane mimetic?
Adults born small are more sensitive to thromboxane mimetic than control.
What effect do age and diet restriction have on vascular function?
Diet restrictions alters vascular function in different ways. Age affects these effects differently.
What effect does protein restriction in the diet have on vasodilation?
Reduction of protein in the diet impacts on both endothelial cells and smooth muscle cells.altering their function
How does low birth weight cause hypertension via vascular resistance effect?
It causes hypertension by increasing total peripheral resistance in response to the same amount of vasoconstrictor
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