Adrenaline vs noradrenaline?

Question

Whats the difference?

Adrenaline does Alpha 1 (and 2?-but 2 doesnt do much right?) and Beta 1,2

while

Noradrenaline does ___________________________?

Thanks

Answer 1

In brain, there is very little epinephrine, and quite a bit of norepinephrine (NE), so NE acts on all adrenergic receptors.  BTW, epinephrine = adrenaline and NE = noradrenaline.

Answer 2

- I love these Qs and Pharmacology in general.

- Epinephrine (adrenaline) has agonistic action on both alpha & beta receptors. At low doses, beta action predominates and at moderate & high doses, alpha effects are strongest.

- Norepinephrine- it has a very weak beta-2 activity. Beta-2 receptors are present in blood vessels (vasodilation) and bronchioles (bronchodilation). Thus, noradrenaline is not useful in treament of asthma.

- Ranks according to potency-

1. Alpha receptors- adrenaline ≥ noradrenaline >> isoproterenol

2. Beta receptors- isoproterenol > adrenaline > noradrenaline

Answer 3

Noradrenaline has a strong affinity towards alpha receptors and only a weak impact on beta receptors.

Gives vasoconstriction of coronary vessels as well as peripheral vessels.