Sweatman: Drugs at the Synapse Flashcards
What type of nerve in the ANS has a long pre-ganglionic neuron and a short postglanic neuron?
Parasympathetic
What is the relative length of the preganglionic of the sympathetic vs. parasympathetic?
Sympathetic is shorter, postganglionic is long
What type of receptor is located in ganglionic neurons and what is the neurotransmitter?
- Nicotinic receptor
- ACh neurotransmitter
What are the postganglionic receptor and neurotransmitter in the parasympathetic division?
- Muscarinic receptor
- ACh neurotransmitter
Suppose a person experiences excessive sweating, What kind of neurtransmitter would you be trying to block?
ACh
What a major issue with giving drugs that act upon the autonomic nervous system?
The receptors are located all over the body, so its hard to affect only a target tissue
What is a difficulty of autonomic drugs, besides difficulties getting autonomic drugs to receptors only in the target tissues.
They often cause an excessive response
What is the advantage of putting a neurotransmitter in a vesicle?
Increase the concentration of the neurotransmitter, increasing your chances of action potential on other side
If you give someone a strong inhibitor of Ach-esterase what is the result?
excessive stimulation of preganglionics
What type of neurotransmitter and receptor are specific sympathetic nervous system?
- alpha (1,2) and beta (1,2,3) receptors
Norephinephrine and Epinephrine neurotransmitters - Dopaminergic (D1 and D2)
Dopamine
Elevated levels of metanephrine and normetanephrine and VMA is indicative of what?
Pheochromocytoma
What is the purpose of co-transmitters?
They modify the effects of the primary neurotransmitter
What is the problem when taking monoamine oxidase inhibitors?
- Tyramine is found in food stuffs
- You can’t breakdown the tyramine
- tyramine pushes NE out of the vesicle
- Articficial sympathetic response results (Elevated heart rate etc.)
What is comT?
works similarly to monoamine oxidase in that it breaks down catecholamines
What happens to specificity once you increase the dose past the clinical window?
A drug that is usually specific for one receptor starts to act on other receptors
What is the point of autoreceptors?
cuts off stimulation or increases stimulation by recognizing the primary neurotransmitter
What is the point of heteroreceptors?
Receptors modulated by a secondary neurotransmitter
This is huge in allowing complementarity between sympathetic and parasympathetic stimulation
Lidocaine
Na+ channel blocker in neuronal axon
Hemicholinium
Blocks choline uptake; depletes Ach availability
Metyrosine
inhibitor of dopamine synthesis; depletes NE
Vesamicol
inhibits vesicle associated transporter, VAT
reserpine
Inhibits vesicular monoamine transporter VMAT
botulinum toxin
Degrades VAMPs and SNAPs - no vesicle fusion
Tyramine
Releases stored transmitters from NE neurons
