Alpha and Beta Receptors Flashcards
where can you find alpha 1 receptors?
vascular smooth muscle, on GI and bladder sphincters, and radial muscle of the eye causing excitation (contraction)
this cholinergic receptor is g-coupled
alpha 1 receptors
this cholinergic receptor increases IP3
alpha 1 receptors
where can you find alpha 2 receptors?
presynaptic nerve terminals, platelets, fat cells, walls of GI tract
this adrenergic receptor causes inhibition?
alpha 2 receptor
Cholinergic and Adrenergic receptors are G-protein coupled? Are nicotinic receptors?
true; no
what is the effect of activating the alpha 2 receptors?
inhibition of adenylate cyclase and decrease in cAMP causing inhibition (dilatation)
where can you find the beta 1 receptors?
SA node, AV node, ventricular muscle of heart
what is the effect of Beta 1 receptors?
stimulation of adenylate cyclase and increase in cAMP causing excitation (increaes heart rate, contactility, increased conduction velocity)
where can you find Beta 2 receptors?
vascular smooth muscle of skeletal muscle, bronchioles, walls of GI tract and bladder
what is the effect of Beta 2 receptors?
stimulation of adenylate cyclase and increase in cAMP, increase epinephrine and this produces relaxation (dilation of vascular smooth muscle and bronchioles, relaxation of bladder wall)
Which of the following are Gq coupled and/or Gi coupled for cholinergic receptors? M1, M2, M3; are these G-protein coupled receptors
M1 and M3 are Gq coupled
M2 is Gi coupled
which of the following are Gq coupled and/or Gi coupled for adrenergic receptors? alpha 1, alpha 2, Beta 1, Beta 2, Dopaminergic 1
alpha 1 is Gq coupled
alpha 2 is Gi coupled
Beta 1, Beta 2, Dopaminergic is Gs coupled
since M1 and M3 are are Gq coupled, what is the effect?
what type of receptors are these?
increase phospholipase C -> increase IP3, DAG, and calcium; cholinergic
since M2 is Gi coupled, what is the effect? what type of receptors are these?
decrease adenylyl cyclase -> decrease cAMP; cholinergic
