Regulation of Vascular Endothelium

Question 1

Which nerves innervate the vascular endothelium?

Answer 1

M3 cholinergic receptors

Question 2

Endothelial cells secrete what kind of vasoconstricters?

Answer 2

angiotensin converting enzyme, thromboxane, free radicals, & endothelin

Question 3

Endothelial cells secrete what kind of vasodilators’?

Answer 3

nitric oxide, prostacyclin

Question 4

What is the role of acetylcholine action in the endothelium?

Answer 4

induces release of NO

Question 5

What will happen if acetylcholine cannot stimulate release of NO due to endothelial damage?

Answer 5

vessels will not be able to relax

Question 6

Describe the downstream effects after Acetylcholine activates M3.

Answer 6

ACh binding releases Ca which binds to calmodulin; calmodulin will activate eNOS to convert L-arginine to NO; NO then activates guanylyl cyclase to convert GTP to cGMP; cGMP activates PKG to relax the vessel

Question 7

Describe the mechanism of Viagra?

Answer 7

PDE-5 inhibitor; PDE-5 degrades cGMP to reverse vasodilation, so if this is blocked, vessels will remain dilated

Question 8

In addition to NO, what other pathways can cause vasodilation?

Answer 8

PG, & EDHF

Question 9

Describe the mechanisms of Von-Willebrand Disease and the treatment?

Answer 9

autosomal dominant; decreased vWF; vWF is crucial for the formation of platelet plug to heal an injured endothelium; treatment is desmopressin which will increase release of vWF from endothelial cells

Question 10

what parts of the vascular endothelium are susceptible to shear stress?

Answer 10

bifurcations

Question 11

which blood vessels account for most TPR?

Answer 11

mesenteric arteries

Question 12

what drugs are used for pulmonary arterial hypertension?

Answer 12

bosentan (endothelin-1 receptor antagonist); Sildenafil (AKA viagra)

Question 13

Endothelin is naturally elevated in pts. w/ T2DM. How will this affect endothelial function?

Answer 13

more endothelin means less NO production which causes the vessels to be constricted for long periods of time; additionally, endothelin is a pro-proliferation factor of smooth muscle cells

Question 14

List the triad of symptoms seen with DVT.

Answer 14

stasis, hypercoagulability, endothelial damage (triggers clotting cascade)

Question 15

How does COVID-19 contribute to endothelial dysfunction

Answer 15

stimulates release of vMF causing coagulopathy

Question 16

Increased production of ROS can cause oxidative stress. Liste epidemiology & treatments

Answer 16

commonly seen in diabetes, HTN, inflammatory disorders, & obesity; oxidative stress increases vasoconstriction; treatment: anti-oxidants; phenols increase eNOS and block NOX proteins that produce ROS