Blockers Flashcards
Cells in the (xxxxx) synthesize and secrete norepinephrine and epinephrine.
adrenal medulla
Following release into blood, these hormones bind (XXXXXX) receptors on target cells, where they induce essentially the same effects as direct (XXXXXX) nervous stimulation.
adrenergic
sympathetic
Ratio for norepinephrine and epinephrine in the adrenal medulla?
80% is epi
20% is NE
How is norepinephrine made?
Tyrosine
DOPA
Dopmaine
Norepinephrine
How is Epinephrine made?
Tyrosine
DOPA
Dopmaine
Norepinephrine
What enzyme is responsible in making Tyrosine into DOPA?
tyrosine hydroxlase
what enzyme is responsible in making DOPA into Dopamine?
DOPA decarboxylase
What enzyme is responsible in making Dopamine into Norepinephrine?
Dopamine B-hyroxylase
What enzyme is responsible for making Norepinephrine into Epinephrine?
phenylethanolamine N-methyltransferase
Norepinephrine and Epinephrine are metabolically degraded by what two compounds?
MAO and COMT
Acetylcholine is broken down by what enzyme? How is it metabolized? What are the two compounds it is broken down into??
Acetylcholinesterase
Acetate + Choline
Norepinephrine and Epinephrine are both ultimately broken down into what compound?
Vanillymandelic Acid (VMA)
The metabolic pathway in the nerve endings for the breakdown of epi and norepi?
MAO to COMT
The metabolic pathway in the liver for the breakdown of epi and norepi?
COMT and MAO
Alpha 1 postsynaptic receptor stimulation causes what?
-Mydriasis (pupillary dilation d/t contraction of radial eye muscles) (fight or flight, you need to let more light in)
-Bronchoconstriction (through AcH)
-Vasoconstriction
-Uterine contracture
(male ejaculation)
-Contraction of sphincters of GI/GU tract
What g protein receptor is alpha 1 post synaptic?
Gs
Alpha 2 pre synaptic receptor stimulation causes?
- Some vasoconstriction of vascular smooth muscle
- Decreased N.E. release
- Sedation (how precedex works, 1600x more specific than clonidine)
- Sympathetic outflow (decreases)
- -Peripheral vasodilation
- -Lowers BP
- Inhibit insulin release from Islet cells (beta cells) (more glucose)
what g protein receptor is alpha 2 pre synaptic?
Gi
What are the non-selective alpha antagonist?
phentolamine
phenoxybenzamine
tolazoline
If it ends in -ine it is non slective
What are the selective alpha 1 antagonist?
Prazosin
Terazosin
Doxazocin
Tamsulosin
What is a selective alpha 2 antagonists?
Yohimbine
What does beta 1 receptor stimulate?
Chronotorpic (increase HR)
Dromotropic (increase conduction)
Inotropic (increase contractility)
What does beta 2 receptor stimulation cause? non cardiac
- Relaxes smooth muscle
- Bronchodilation
- Vasodilation (b/c there are some beta 2 in the periphery, mostly alpha receptors)
- Relax uterus/bladder/gut
- increase Glycogenolysis, lipolysis, gluconeogenesis (making glucose from aminoacids & from the glycerol portion of fat), insulin hypoglycemiagluconeogenesis).
- Activation of Na/K pump
- –K goes intracellular (can produce hypoK & dysrhythmia)
What are non selective beta antagonists?
propranolol
timolol
nadolol
pindolol
If the name starts after N is nonslecetive
what are selective beta 1 antagonists?
atenolol
esmolol
metoprolol
If the name starts between A-M it is selective
Alpha antagonists Inhibits action of NE at (XXXXX) synaptic receptors (reversible or irreversible)
post
NE is release presnyaptically, the alpha antagonist will inhibit the presynaptic site to prevent the release of NE. Therefore NE cannot stimulate postsynaptic. Will block pre and post synaptic alpha receptors.
Alpha antagonists Attenuates sympathetic responses which two places in the body?
heart, peripheral vasculature
true or false?
Alpha antagonists dont produce orthostatic hypotension, baroreceptor reflex tachycardia
False
Alpha antagonists MAY produce orthostatic hypotension, baroreceptor reflex tachycardia
true or false?
α blockade inhibits epinephrine’s effect on insulin secretion
True
α blockade inhibits epinephrine’s effect on insulin secretion
What is reversible inhibition?
- Competitive binding at receptor site**
- Effects of inhibition may be overcome by administering sympathomimetic
Competitive, if you give more of the stimulant you should be able to overcome the effect, this is for reversible
You wont be able to do that if it is irreversible