Exam 4 Flashcards
(24 cards)
Nicotinic Receptors
ligand gated ion channels for ACh
1 types: Nm and Nn
Nm
muscular nicotinic receptors
on skeletal muscle innervated by somatic ACh neurons
Nn
neuronal nicotinic receptors
on post-ganglionic neurons and adrenal medulla
Ion channel desensitization
if open/activated by agonists for a long time, it shuts itself off. with a gate. so the cell can repolarize.
the gate will fall away when the cell is ready! Can’t chemically speed this up, must WAIT.
muscular nicotinic receptor antagonists
competitively block the ACh binding site on the Nm receptor
cause FLACID paralysis
Non-depolarizing blockers
reversible (increase ACh levels), more safe
nicotinic receptor agonists
depolarizing blockers cause opening of the ion channel cause muscle contraction such high affinity that it will cause blocking of the channel, cause SPASTIC paralysis Irreversible, less safe
Nondepolarizing neuromuscular blockers
curare like
only skeletal paralysis for 80-120 min but still feel pain!
Eye, Jaw, Throat and neck, Appendages, Ab muscles, Intercostal muscles and diaphragm
Dose titrated to keep breathing
treat with AChE inhibitors
Curare-like drugs
nondepolarizing
synthetics Cistracurium Nm, can't cross ganglionic space Pancuronium Nm, kidney Vecuronium Nm, liver Rocuronium Nm, liver
Depolarizing neuromuscular blockers
Succinylcholine Nm
Succinylcholine
cause twitching at first for 1 min. then Blockage.
5 minute paralysis
hydrolyzed by pseudocholinesterases
no antidote
hyperkalemia
malignant hyperthermia with inhalant anesthetics, treated with dantrolene
Botulin toxin
from clostridium botulinum of food poisoning
inhibits calcium dep binding of vesicles inhibiting NT release
Botox
tetrodotoxin
pufferfish toxin
sodium channel blocker
Nicotine
depolarizing neuronal nictotinic blocker (Nn)
depolarizing neuronal nicotinic receptor blockers
dump of Norepi into bloodstream. surge in BP from sympathetic receptors
then blockage=calming from parasympathetic
Varencline
partial agonist and full agonist at nicotinic receptor
AChE inhibitors effect seen on:
Parasympathetic Target Organs
and
Somatic (Voluntary) striated muscles
Gives agonists to increase muscle contraction where it is weak because that’s where the ACh is.
Effect of AChE inhibitor on blood pressure
predictably will raise blood pressure. When used for increasing blood pressure, the agent MUST cross the ganglionic space.
What effects with AChE inhibitors?
Reduction of HR (bradycardia) sweating urination diarrhea miosis lacrimation Salivation bronchoconstriction
What conditions are AChE inhibitors used for
Glaucoma Orthostatic hypotension.. Myasthenia Gravis Antidotes for competitive muscarinic antagonists Alzheimer's --MOST
Side effects of AChE inhibitors
Drop in heart rate
incontinence (urine)
wetness (sweating, lacrimation, salivation)
Twitching
AChE inhibitors that cross the ganglionic barrier and CNS
physostigmine rivastigmine donepezil galantamine huperzine A
Glaucoma treatment
Timolol–beta blocker, decrease production of aq humor
apraclonidine-alpha 2 decrease cAMP decrease aq humor production
brimonidine-alpha 2 decrease cAMP decrease aq humor
pilocarpine-muscarinic agonist, increase flow of aq humor
AChE Inhibitors-echothiofate
carbonic anhydrase inhibitors
dorzolamide
brinzolamide
prostaglandin analogues
allow for increased uptake of aq humor
latanoprost, bimatoprost, travoprost, tafluprost
permanent pigmentation and increase eye lash growth.
