Peripheral Neural Transmission Flashcards
Dexamfetamine
Weak inhibitor of MAO
Reduces pH gradient and packaging of amines
Displaces NA from vesicles
Dobutamine
β1 selective agonist
Sympathomimetic
Used in heart failure and acute cardiogenic shock
Nicotine
Nicotinic agonist
Parasympathomimetic
Mecamylamine
Non-selective nicotinic antagonist
Non-competitive
Antihypertensive
β-bungarotoxin
Irreversible NMJ blockade
Acts through phospholipase A2
Localises to the membrane by a K+ channel-binding moiety
Blocks ACh release
Causes paralysis
Phentolamine
Non-selective α antagonist
Vasodilatation due to α1 blockade
Obsolete antihypertensive as brings about large increase in heart rate
Isoprenaline
Non-selective β agonist
Used for bradycardia and heart block
Suxamethonium
Nicotinic agonist
Depolarising NMJ blocker
Short-acting
Used for intubation
Ester broken down by plasma BuChE
Darifenacin
M3 antagonist
Mediates reduction of bladder contraction in urinary incontinence
Pilocarpine
Non-selective muscarinic agonist
Used to treat glaucoma via eye drops
Absorbed through conjunctival membrane
Contracts the ciliary muscle to produce traction on the trabecular meshwork which facilitates aqueous humour drainage and lowering intraocular pressure
Idazoxan
α2 antagonist
Reserpine
Irreversibly blocks VMAT
Causes NA depletion
Antihypertensive
Causes profound psychological depression
Salbutamol
β2 agonist
Relief of bronchospasm in asthma
Selegiline
MAO-B selective inhibitor
Used to treat Parkinson’s
Butaxamine
β2-selective antagonist
Clonidine
α2 agonist
Slightly selective for α2
Antihypertensive
Xylazine
α2 agonist
Sedative in CNS
Used in vet medicine
Tranylcypromine
Irreversible MAO inhibitor
Non-selective
Treatment of refractory depression
Pancuronium
Competitive nicotinic antagonist at NMJ
Non-depolarising blocker
Long action as not hydrolysed
Atracurium
Nicotinic antagonist at NMJ
Skeletal muscle relaxant
Non-depolarising block
α-methyldopa
False transmitter
Replaces noradrenaline in vesicles
Antihypertensive in CNS
Pralidoxime
Reverses inhibition by organophosphorus agents
Combat poisoning by organophosphates and anticholinesterases
Brings the oxime group, a strong nucleophile, into close proximity with the phosphorylated serine of the inhibited enzyme
Phosphate group is then transferred to the reactivator
Only effective for a few hours due to ageing
Clorgiline
MAO-A inhibitor
Irreversible
Used in treatment of depression
Bethanechol
Non-selective muscarinic agonist
Used systemically for bladder dysfunction
ADMA
Endogenous NOS inhibitor
Increased level in hypercholesterolaemia and renal failure
Metabolised by dimethylarginine dimethylaminohydrolase which is downregulated by NO
Caffeine
A1 receptor antagonist
CNS and metabolic stimulant
Reduces fatigue - waking action is most prominent after prolonged wakefulness
Inhibits phosphodiesterase
Increases rate and force of cardiac contraction
Guanethidine
Reduces NA release
Replaces NA in vesicles
Taken into cell by uptake 1
Entacapone
COMT inhibitor
Used in Parkinson’s disease
Edrophonium
Reversible short-acting AChE inhibitor
Binds only to ionic site
Used to diagnose myasthenia gravis
Dyflos
Irreversible anticholinesterase
Used in glaucoma
Forms strong covalent bond with AChE
Cocaine
NET transporter blocker
Increases extracellular NA
Carbidopa
Peripheral DOPA decarboxylase (DDC) inhibitor
Acts only peripherally as can’t cross blood brain barrier
Used in Parkinson’s disease
Botulinum toxin
Cleaves SNARE proteins
Inhibits ACh release
Causes flaccid paralysis
Atenolol
β1-antagonist
Antihypertensive
Also used in angina and dysrhythmias
Amitriptyline
Tricyclic antidepressant
Blocks NET transporter
Prevents serotonin and NA reuptake
α-latrotoxin
Black widow spider venom
Binds to neurexins
Forms calcium permeable pores leading to massive ACh release
Tyramine
Displaces NA in vesicles
Can cause hypertensive crisis in combination with MAO inhibitors - cheese effect
Found in food stuff
Tetanus toxin
Targets SNARE proteins (synaptobrevin)
Inhibits inhibitory interneurons
Increases excitability of motor neurons
Sildenafil
Selective phosphodiesterase V inhibitor
Used to treat impotence and pulmonary arterial hypertension
Viagra
Propranolol
Non-selective β antagonist
Antihypertensive
Prazosin
Selective α1 antagonist
Used in hypertension and Raynaud’s disease
Phenylephrine
α1 agonist
Decongestant
Raises blood pressure in acute hypotension
Nitroglycerin (glyceryl trinitrate)
Generates nitric oxide
Vasodilator
Used to treat angina
Neostigmine
Reversible anticholinesterase
Indirectly stimulates ACh receptors
Binds to esteratic site and carbamoylates enzyme
Used IV to reverse NMJ blockade after surgery
Treatment of myasthenia gravis
Muscarine
Muscarinic agonist
Competitive
Labetalol
α1, β1 and β2 antagonist
Used to treat hypertension in pregnancy
Imipramine
Tricyclic antidepressant
Blocks NET transporter
Inhibits NA reputake
Hexamethonium
Non-depolarising ganglion blocker
Nicotinic receptor antagonist
Causes loss of both sympathetic and parasympathetic
Hemicholinium
Blocks reuptake of choline by choline transporter
Reuptake of choline is rate-limiting step
Dipyridamole
Blocks adenosine transport into cells
Inhibits phosphodiesterase
Atropine
Non-selective muscarinic antagonist
Produce dilatation of the pupils (mydriasis)
Benzilylcholine mustard
Non-selective muscarinic antagonist
Irreversible
Isosorbide dinitrate
NO donor
Nitrovasodilator
Used in treatment of angina
Malathion
Irreversible anticholinesterase
Forms strong covalent bond
Used as insecticide in headlice treatment
