Flashcards in General Adrenergic Receptors Deck (13)
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1
Which type of adrenergic receptor is a G-alpha-q receptor?
Alpha 1
2
What kind of signal is sent by the alpha-1 g-alpha-q receptor?
An excitatory signal to the blood vessels.
3
What second messengers are activated by the g-alpha-q receptor and what does this result in?
Phospholipase C (PLC) is activated which hydrolyzes phosphoinositol (PIP2) into IP3 and DAG. IP3 causes an increased release of intracellular calcium and DAG activates protein kinase C which causes the phosphorylation of proteins causing them to be activated.
4
What type of a physiologic response results from activation of the alpha-1 g-alpha-q receptor?
Smooth muscle constriction.
5
Which type of adrenergic receptor is a g-alpha-i receptor?
Alpha-2
6
What kind of signal is sent by the alpha-2 g-alpha-ireceptor?
Inhibitory.
7
To which three places do the alpha-2 q-alpha-i receptors send inhibitory signals?
1. Brain
2. Blood vessel
3. Pre-synaptic on the post ganglionic neuron innervating the blood vessels.
8
What second messengers are inactivated by the alpha-2 g-alpha-i receptors?
Adenylate cyclase is inactivated so ATP cannot be converted into cAMP. So we have a decrease in cAMP and potassium conductance is increased.
9
What type of physiologic responses result from activation of the alpha 2 g-alpha-i receptor?
Smooth vessels constrict (cAMP is responsible for smooth muscle relaxation). Potassium conductance is increased and the cell is hyperpolarized.
10
What types of adrenergic receptors are g-alpha-s receptor?
Beta 1, 2 & 3.
11
What kind of signal is sent by the beta 1, 2 & 3 g-alpha-s receptors?
It could be excitatory or inhibitory depending on cAMP actions.
12
What second messenger is activated by the beta 1, 2 & 3 g-alpha-s receptors?
The activation of adenylate cyclase is responsible for converting ATP into cAMP.
13
