Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Cholinergic Pharm
Pharmacolgy Exam 2
| Question | Answer |
|---|---|
| What is one of the only sites in the sympathetic nervous system where a postganglionic neuron releases acetylcholine onto a muscarinic receptor? | Sweat glands |
| What are the two substrates required to produce acetylcholine? | Choline + Acetyl-CoA |
| What is the function of the choline transporter? (CHT) | The choline transporter functions in bringing extracellular choline into the neuron |
| What is the function of choline acetytransferase? (ChAT) | ChAT synthesizes acetylcholine by combining choline and acetyl-CoA |
| What is the function of Vesicle Associated Transporters? (VAT) | VAT transports acetylcholine into the vesicles for storage. |
| How is the release of Ach in the synaptic cleft initiated? | Voltage gated Ca++ channels open after an action potential passes through the cell. This causes the fusion of acetylcholine-containing vesicles with the membrane |
| What enzyme terminates Ach's actions? | Acetylcholinesterase |
| What is the function of heteroreceptors? | Heteroreceptors are activated by substances released from other nerve terminals that synapse with the nerve ending |
| What is the function of autoreceptors? | Autoreceptors respond to their own substance release |
| What are Vesicle Associated Membrane Proteins? (VAMPs) | VAMPs align vesicles with their release site on the cell membrane (inside the neuron) |
| What are Synaptosomal nerve-associated proteins? (SNAPs) | SNAPs are the release site outside of the cell in the nerve terminal membrane |
| What types of drugs affect the parasympathetic nervous system? | Cholinergic |
| What are the two types of receptors that acetylcholine binds to? | Nicotinic & Muscarinic |
| What is the rate limiting step in the synthesis of norepinephrine? | Tyrosine -------> Dopamine *Tyrosine Hydroxylase* |
| How is norepinephrine released from the terminal? | Voltage gated Ca++ channels open after an action potential passes through. Increases in intracellular Ca++ causes the fusion of the norepinephrine-containing vesicles with the membrane. |
| What types of drugs block the reuptake of norepinephrine? | Antidepressants and cocaine |
| Once norepinephrine is release from the cell, what happens to it? | a) diffuses out of the cleft b) transported into the cytoplasm of the terminal by the Norepinephrine Transporter (NET) |
| How is norepinephrine synthesized? (Describe the process) | 1. Tyrosine is brought into the cell via a sodium-dependent carrier 2. Tyrosine is converted into dopamine via tyrosine hydroxylase 3. Dopamine is transported in to a vesicle via VMAT and covnerted into norepinephrine via dopamine-beta-hydroxylase |
| Compounds derived from the amino acid Tyrosine are called | catecholamines |
| What types of tissues/organs do muscarinic receptors innervate? | Nerve, heart, smooth muscle, glands, endothelium |
| Where are muscarinic receptors found? | Muscarinic receptors are found on ORGANS and in the brain *heart, bronchioles, stomach, intestine, pancreas, eye, mouth* |
| Where are nicotinic receptors found? (what do they innervate?) | Nueromuscular end plate, skeletal muscle, & autonomic ganglion cells, |
| What are the functions of muscarinic receptors 1, 3, & 5? | Muscarinic 1, 3, 5 Stimulate Phospholipase C as a second messenger |
| What are the functions of muscarinic receptors 2 & 4? | Muscarinic 2 & 4 inhibit adenylate cyclase open K+ channels (hyperpolarize) close Ca++ channels (block entry of Ca++ that mediates cellular activity) |
| What is chronotropy? | Chronotropy affects time or rate (i.e. heart rate) |
| What is dromotropy? | Dromotropy affects conduction |
| What is inotropy? | Inotropy affects the force of contraction |
| What are the effects of parasympathomimetics on the heart? | 1. Bradycardia (negative chronotropy) 2. Decrease conduction (negative dromotropy) 3. Decrease force of contraction (negative inotropy) |
| What are the effects of parasympathomimetics on the GI system? | In GI smooth muscle, increased tone and motility of the wall muscles and relaxation of sphincters |
| What are the effects of parasympathomimetics on the bladder? | In bladder, the body (detrussor mm) contracts while sphincters relax |
| What are the effects of parasympathomimetics on the lungs? | In lungs, bronchoconstriction and increase secretion |
| What are the effects of parasympathomimetics on the eyes? | In the eye, contraction of the ciliary mm (lens) and circular mm of the iris (accommodate for close up vision) |
| What are the effects of parasympathomimetics on the exocrine gland? | In exocrine glands, promotes secretion (anomylous) |
| Muscarinic receptors cause a ___________ response. | SLUDGE S = Salivation L = Lacrimation U = Urination D = Defecation G = GI upset E = Emesis (vomiting) |
| Acteylcholine and some analogues with similar chemical structures are known as ____________ | choline esters |
| Parasympathomimetics include what class of drugs? | Muscarinic agonists, nicotinic agonists, choline esters |
| What are the four types of choline esters? | Acetylcholine, methacholine, carbachol, & bethanechol |
| Which two choline esters have negligible susceptibility to cholinesterase? What is the significance of negligible susceptibility to cholinesterase? | a. Carbachol & Bethanechol b. Longer half-lives |
| What is bethanechol used in the treatment of? | Bethanechol is used in the treatment of postpartum or postoperative nonobstructive urinary bladder retention (causes the urinary sphincter to relax so that urine can be expelled) |
| To which class does bethanechol belong? | Choline Ester |
| To which class does carbachol belong? | Choline Ester |
| What is carbachol used in the treatment of? | Mitotic agents (small pupil) Treatment for glaucoma |
| What are the two types of muscarinic agonists? | Muscarine and Pilocarpine |
| What class does muscarine belong to? What is it used for? | Muscarine is a muscarinic agonist. It is a toxin from mushrooms. MUSCARINE = TOXIN |
| What class does pilocarpine belong to? What is it used for? | Pilocarpine is a muscarinic agonist. It is used in the treatment of glaucoma. |
| What is muscarinic toxicity? What are the symptoms? | Too much muscarinic antagonist. Severe SLUDGE reactions. Death can occur due to respiratory failure. |
| What is the antidote to muscarinic toxicity? | Atropine |
| What are some "anti-parasympathetic" effects observed from muscarinic antagonists? | tachycardia, constipation, urinary retention, hypertension, bronchodilation, dry mouth, pupil dilation |
| To which class does atropine belong? | Muscarinic Antagonist |
| To which class does scopalamine belong? | Muscarinic Antagonist |
| What is atropine used for? | Anti-Diarrhea cardiac support (crash cart) pre-operative antisecretory agent |
| What is scopalamine used for? | Anti-nausea |
| To which class does ipratropium belong? | muscarinic antagonist |
| What is ipratropium used for? | bronchodilator |
| What is a side effect of ipratropium? | dry mouth |
| To which class does tiatropium belong? | muscarinic antagonist |
| What is tiatropium used for? | bronchodilator - COPD longer half life than ipratropium |
| To which class does methscopolamine belong to? | muscarinic antagonist |
| What is methscopolamine used for? | GI spasms |
| What is homoatropine used for? | GI Spasms, irritable bowel |
| To which class does homoatropine belong? | muscarinic antagonist |
| To which class does proantheline belong? | muscarinic antagonist |
| What is proantheline used for? | ulcers |
| To which class does glycopyrrolate belong? | muscarinic antagonist |
| What is glycopyrrolate used for? | Anti-vagal during surgery stops visceral muscle movement |
| To which drug class does pirenzepine belong? | Muscarinic antagonist |
| What is pirenzepine used for? | anti-peptic disorder |
| Which receptors is pirenzepine specific for? | M1 & M4 |
| To which drug class does darifenacin belong? | Muscarinic antagonist |
| What is darifenacin used for | Darifenacin (Enablex) is used in the treatment of urinary or fecal incontinence |
| Which receptor is darifenacin selective for? | Darifenacin (Enablex) is specific for the M3 receptor |
| To which class does oxybutnin belong? | Oxybutnin (ditropan) is a muscarinic antagonist |
| What is oxybutnin used for? | Oxybutnin (ditropan) is used to relax the detrussor muscle (for bladder incontinence) |
| To which class does tolterodine belong? | Tolterodine (Detrol) is a muscarinic antagonist |
| What is tolterodine used for? | Tolterodine (Detrol) is used to relax the detrussor muscle (for bladder incontinence) |
| Benztropine, Trihexyphenidyl, Biperiden, Procyclidine are all examples of what class of drugs? What are they used for? | Benztropine, Trihexyphenidyl, Biperiden, Procyclidine are muscarinic antagonists used in the treatment of Parkinson's |
| What are indirect cholinergic agonists? | Indirect cholinergic agonists are drugs that stimulate Ach receptors because they inhibit acetylcholinesterase |
| To which class does echothiophate belong? | Indirect muscarinic agonist |
| To which class does diisopropylfluorophosphate (DFP) belong? | indirect muscarinic agonist |
| What are indirect muscarinic agonists used in the treatment of? | glaucoma |
| What is echothiophate used in the treatment of? | Glaucoma |
| What is diisopropylfuorophosphate used in the treatment of? | glaucoma |
| What is the significance of the quartenary amine on ipratropium and tiatropium? | The positively charged amine on ipratropium and tiatropium keep the drugs from crossing the BBB (since charged molecules can't cross) |
| What is myasthenia gravis? | An autoimmune disorder in which there is a loss of nicotinic receptors on the motor end-plate of skeletal muscle. Leads to insufficient receptor stimulation and weakness. |
| What medication is used to test for myasthenia gravis? | Edrophonium |
| How is edrophonium used to diagnose myasthenia gravis? | If the patient immediately gets better after administration, it is a POSITIVE diagnosis of myasthenia gravis. If the patient gets worse, it's a negative diagnosis. |
| What class of medications is used in the treatment of cognitive disorders of Alzheimer's? | Indirect Nicotinic Agonist |
| Which medications belong to the Indirect Cholinergic Agonists / Cholinesterase Inhibitor class? | Phyostigmine, Tacrine, Donepezil, Galantamine |
| To which drug class does phyostigmine belong? | Indirect Nicotinic Agonist |
| To which drug class does Tacrine belong? | Indirect Nicotinic Agonist |
| To which drug class does Donepezil belong? | Indirect Nicotinic Agonist |
| To which drug class does Galantamine belong? | Indirect Nicotinic Agonist |
| There is no quartenary amine on phyostigmine, tacrine, donepezil, or galantamine. What is the significancce? | No charge on the Nitrogen means that the drug is able to cross the BBB. |
| To which class do bug poisons belong? | Indirect Nicotinic Agonist |
| To which class does parathion, malathion, Sevin, and Chlorpyriphos belong? | Indirect Nicotinic Agonist |
| To which class do human poisons used in war belong? | Indirect Nicotinic Agonist |
| To which class does Sarin, Soman, and VX (dermal) belong? | Indirect Nicotinic Agonist |
| What is the goal of cholinesterase inhibitors? | Inhibit Achase, which will in turn increase the amount of Ach concentrations and the duration of its effects. |
| Inhibition of cholinesterase produces an increase in ________________ | skeletal muscle contractions AKA fasciculations |
| Inhibition of cholinesterase produces an increase in skeletal muscle contractions (fasciculations), followed by _____________ | loss of control and paralysis |
| Explain how cholinesterase works | see notes |
| What are the three main classes of cholinesterase inhibitors? | Quarternay amines, carbamates, and organophosphates |
| To what class of cholinesterase inhibitors does edrophonium belong? | Quaternary amine |
| How does edrophonium work as a quarternary amine cholinesterase inhibitor? | blocks the binding site on the enzyme. the positively charged nitrogen binds to the anionic site where Ach would normally bind. |
| To what class of cholinesterase inhibitors does neostigmine belong? | carbamates |
| How does neostigmine work as a carbamate cholinesterase inhibitor | neostigmine attaches a hydroxyl group to the serine. the group comes off slowly, making the drug's effects last longer. |
| To what class of cholinesterase inhibitors does diisofluorophosphate belong? | Organophosphate |
| How does diisofluorophosphate work as a organophosphate cholinesterase inhibitor? | DFP binds to the esteratic site (where the serine is). |
| Why is the binding of diisofluorophosphate to the esteratic site of cholinesterase considered irreversible? | The hydrolysis of phosphorylated esteratic site is so slow that it is considered irreversible |
| How do you remove diisofluorophosphate from the esteratic site of cholinesterase? | by adding pralidoxime, which will bind to DFP, making a stronger bond than DFP had to the esteratic site. the new whole molecule can now leave cholinesterase together. |
| What happens when you add water to the phosphorylated cholinesterase enzyme after diisofluorophosphate has bound? | "aged" enzyme irreversibley bound. permanent. |
| If pralidoxime is added after the aging process of the cholinesterase enzyme has occurred, will it still work? | no. |
| pralidoxime is classified as what? | reactivator |
| Glaucoma is often treated with which muscarinic class of drugs? | Muscarinic agonist |
| What molecule would block the transport of choline into the cell? | hemicholiniums |
| what molecule would block the transport of Ach into the vesicles? | vesamicol |
| what molecule would block the actions of VAMPs and SNAPs? | botulinum toxin |
Created by:
balyons01
Popular Pharmacology sets