Pharmacology - Autonomics I Flashcards
Postganglionic PS fibers release:
Aceytlcholine
“cholinergic”
Postganglionic symptathetic fibers generally release:
Norepinephrine
“adrenergic”
T/F: Not all postganglionic sympathetic fibers are adrenergic - other NTs can be used.
True
All preganglionic neurons, both sympathetic and parasympathetic, release:
ACh and stimulate nicotinic receptors on postganglionic neurons
All preganglionic neurons, both sympathetic and parasympathetic, release ACh and stimulate ______ receptors on postganglionic neurons.
Nicotinic
All postganglionic PS neurons release ACh and stimulate _____ ACh receptors on target tissues.
Muscarinic
Postganglionic symptathetic fibers to sweat glands release:
ACh
Postganglionic sympathetic fibers to renal vessels release:
Dopamine
____ blocks ACh and, when, injected, can locally inhibit muscle contraction.
Botulinim Toxin A
Drugs that block NE synthesis, storage or release, for example, guanethidine, are useful in several diseases like hyptertension, because they block _____ function
sympathetic, but NOT parasympathetic
What is the physiologic effect of cocaine?
To block NE uptake –> increase adrenergic transmission
Cholinoceptors include:
Muscarinic
Nicotinic
Where are M1 receptors found?
Location:
CNS
sympathetic PG neurons
Effects:
formation of IP3 and DAG
increased intracellular Ca
**same as M3 receptors (exocrine glands, CNS, vessels)
**same as M5 receptors (vascular endothelium esp cerebral vessels, CNS)
Where are M2 receptors found?
Location:
Myocardium
Smooth muscle
CNS
Effects:
open K channels
inhibit Adenyl cyclase
**same as M4 receptors (CNS)
Nicotinic receptors, both Nn (N2) and Nm (N1) have what effect?
Opening of Na and K channels, depolarization
Where are Nm (N1) receptors found?
Skeletal muscle neuromuscular end plates
What is the effect of Alpha 1 adrenergic receptors?
Effects:
Formation os IP3 and DAG
increased intracellular Ca
Location:
Postsynaptic effector cells esp smooth muscle
What is the effect of Alpha 2 (adrenoreceptors) receptors?
Effects:
Inhibition of adenyl cyclase
decreased cAMP
Location: Presynaptic adrenergic nerve terminals, platelets lipocytes smooth muscle
All beta (adrenoreceptors) receptors have what function?
stimulate AC
increase cAMP
all found in heart, beta-1 found most widespread in the body
All muscarinic receptors (M1-M5) are
GPCRs
M2, M4 –> Gi (decrease cAMP, hyperpolarize) –> inhibition of neurotransmitter release
M1, M3, M5 –> Gq (increase IP3 and DAG)
**enables ACh to have specific effects, depending on the receptor
Class: Bethanechol
Direct acting carbamic acid ester
cholinomimetic
MOA: Bethanechol
Direct-acting muscarinic cholinomimetic
Uses: Bethanechol
Post-operative and neurogenic ileus; urinary retention (bowel and bladder smooth muscle ACh-innervated)
Side Effects: Bethanechol
SLUDGE
Salivation: stimulation of the salivary glands
Lacrimation: stimulation of the lacrimal glands
Urination: relaxation of the internal sphincter muscle of urethra, and contraction of the detrusor muscles
Diaphoresis
Gastrointestinal upset: Smooth muscle tone changes causing gastrointestinal problems, including diarrhea
Emesis: Vomiting
Class: Pilocarpine
Direct acting non-ester alkaloid
cholinomimetic
MOA: Pilocarpine
Direct-acting muscarinic cholinomimetic
Uses: Pilocarpine
Glaucoma (ACh activates sphincter and ciliary muscles of eye)
Side Effects: Pilocarpine
SLUDGE
Salivation: stimulation of the salivary glands
Lacrimation: stimulation of the lacrimal glands
Urination: relaxation of the internal sphincter muscle of urethra, and contraction of the detrusor muscles
Diaphoresis
Gastrointestinal upset: Smooth muscle tone changes causing gastrointestinal problems, including diarrhea
Emesis: Vomiting
Class: Cevimeline
Direct acting non-ester alkaloid
cholinomimetic
MOA: Cevimeline
Direct-acting muscarinic cholinomimetic
Uses: Cevimeline
Dry mouth/xerostomia (in, e.g., Sjogren’s, post-radiation therapy; via increased salivation)
Side Effects: Cevimeline
SLUDGE
Salivation: stimulation of the salivary glands
Lacrimation: stimulation of the lacrimal glands
Urination: relaxation of the internal sphincter muscle of urethra, and contraction of the detrusor muscles
Diaphoresis
Gastrointestinal upset: Smooth muscle tone changes causing gastrointestinal problems, including diarrhea
Emesis: Vomiting
Class: Nicotine
Direct acting non-ester alkaloid
cholinomimetic
MOA: Nicotine
Direct-acting muscarinic cholinomimetic
Uses: Nicotine
Smoking cessation/reduces craving
Class: Physiostigmine
Indirect acting carbamate
cholinomimetic
MOA:
Physostigmine
Echothiophate
AChE inhibitor (short acting)
Uses:
Physostigmine
Echothiophate
Glaucoma (ACh activates papillary sphincter and ciliary muscles of eye)
Side Effects: Physostigmine
SLUDGE
general increase in cholinergic neurotransmission;
paralysis
Class: Muscarine Pilocarpine Cevimeline Nicotine
Direct acting non-ester alkaloid
cholinomimetic
Uses:
Pilocarpine
Physostigmine
Echothiophate
Glaucoma
Class: Edrophonium
Indirect acting non-ester
cholinomimetic
MOA: Edrophonium
AChE inhibitor (v. short acting)
Uses:
Edrophonium
Pyridostigmine
Neostigmine
Myasthenia Gravis
Side Effects: Edrophonium
SLUDGE
general increase in cholinergic neurotransmission;
paralysis
Class: Neostignmine
Indirect acting carbamate
cholinomimetic
Class:
Neostigmine
Physostigmine
Indirect acting carbamate