Adrenergic Receptors (Heart and Vasculature)

Question 1

Which adrenergic receptors are primarily expressed in the vascular beds?

Answer 1

Alpha 1/Beta 2

Question 2

Activation of Alpha 1/2 causes ___ while activation of beta 2 result in ____

Answer 2

Vasoconstriction, vasodilation

Question 3

Both alpha 1/2 are found in what specific vascular bed?

Answer 3

Skeletal muscle

Question 4

While B1/2 are primarily expressed in ___, an organ, A1 is primarily expressed in ____

Answer 4

the heart; myocardium

Question 5

What does activation of B1/2 result in? (4)

Answer 5

1) Increase HR (positive chronotropic effect)
2) Increase conduction velocity
3) Increase myocardium contractility (positive inotrophic effect)
4) Increase CO

Question 6

What does activation of A1 cause?

Answer 6

1) Minor positive inotrophic effect

Question 6

What does activation of A1 cause?

Answer 6

1) Minor positive inotrophic effect

Question 7

While A1/B1 receptors are located in the post-synaptic, A1/B2 are located in the ___ and ___. What do they do at these locations?

Answer 7

Pre-synapse and Extrajunctional

PS: A1: (-) feedback, B2: (+) feedback
Extrajunctional: activated preferentially by circulating catecholamines