Lecture 7 p1 Flashcards
how does the transmitter Acetylcholine interact
The transmitter ACETYLCHOLINE interacts with distinct subclasses of cholinoceptors at different cholinergic synapses.
what does the specificity of distinct cholinoceptors allow for
selective pharmacological interventions
ACh serves as the mediator at terminals of
- All postganglionic parasympathetic nerve fibres
- Preganglionic synapses within both the sympathetic & parasympathetic ANS
- Neuromuscular junction of skeletal muscle
Neurotransmitter ACh is usually very quickly hydrolyzed and inactivated by what highly active enzyme
acetylcholinesterase (AChE)
2 main groups of Cholinomimetics
Direct acting agonists vs Indirect acting enzyme inhibitors
Muscarinic agonist: PILOCARPINE
Pilocarpine-containing eye drops for the treatment of glaucoma, a group of ocular diseases with abnormally high intraocular pressure. Reduction of IOP is achieved by contracting the ciliary muscle which increases aqueous outflow
Enzymeinhibitor: NEOSTIGMINE
Neostigmine is a anticholinesterase drug used in the treatment of myasthenia gravis. Anti-AChE drugs increase the amount of ACh available in the synaptic cleft, thus counteracting MG.
What is myasthenia gravis
an autoimmune disease in which neuromuscular transmission is defective due to the loss of functional nACh receptors in skeletal muscles.
What Cholinergic Drug is a Muscarinic Agonists
Pilocarpine
what is Pilocarpine used for
Treatment of glaucoma
What Cholinergic Drug is a Muscarinic Antagonists
- Atropine
- Hyoscine
What is Atropine used for
Blocking of vagal slowing of heart during surgery
what is Hyoscine used for
Prevention of motion sickness
What Cholinergic Drug is Ganglion-stimulating Nicotinic Agonists
Nicotine
What Cholinergic Drug is Ganglion-blocking Drugs
- Trimetaphan
- Hexamethonium
what are Trimetaphan and Hexamethonium used for
Anti-hypertensive action
What Cholinergic Drug is Anti-Cholinesterases
- Neostigmine
- Phyostigmine
what is Neostigmine used for
Reversal of non-depolarizing neuromuscular blockade
What is Phyostigmine used for
Treatment of myasthenia gravis
What Cholinergic Drug is a Non-depolarizing Neuromuscular Blockers
- Tubocurarine
- Pancuronium
What is Tubocurarine and Pancuronium used for
- Neuromuscular blockade
- used during surgery
What Cholinergic Drug is a depolarizing Neuromuscular Blockers
Suxamethonium
What is Suxamethonium used for
- Neuromuscular blockade
- used during surgery
Nicotine properties
- Alkaloid
- Extracted from tobacco plant Nicotiana tabacum
- Activates a specific subclass of ACh receptors (nAChR)
Muscarine properties
- Alkaloid
- Extracted from poisonous mushroom Amanita muscaria
- Activates a specific subclass of ACh receptors (mAChR)
Where is the anatomical localisation of Ach muscarinic
Parasympathetic system
What is the receptor type for ACh muscarinic
M-AChR: G-protein coupled seven-transmembrane receptor
Where is the anatomical localisation of Ach nicotinic
- Sympathetic and parasympathetic system
- Skeletal muscle Neuromuscular junction
What is the receptor type for ACh nicotinic
N-AChR: Five transmembrane subunit receptor Cation channel
