ANS 2 Flashcards
what are the effects of anticholinesterases on the ANS?
Salivation Lacrimation Urination Defecation Gastrointestinal upset Emesis
Bradycardia
Bronchoconstriction
Hypotension
Pupillary constriction (miosis)
what are predominate locations of nicotinic Ach receptors?
- NMJ
- sympathetic ganglia
- parasympathetic ganglia
- CNS
what are predominate locations of muscarinic Ach receptors?
- parasympathetic target organs
- sweat glands (sympathetic)
- vascular smooth muscle
- CNS
which agonists have specificity with muscarinic receptors?
- acetylcholine
- muscarine
- bethanechol
- pilocarpine
which agonists have specificity with nicotinic receptors?
- achetylcholine
- nicotine
which agonists do nicotinic and muscarinic Ach receptors share?
achetylcholine
what are the 3 classes of muscarinic Ach receptors?
- M1 (neural)
- M2 (cardiac)
- M3 (glandular/smooth muscle)
what are the main locations of M1 (neural) Ach receptors?
autonomic ganglia glands:
- gastric
- salivary
- lacrimal
what are the main locations of M2 (cardiac) Ach receptors?
- heart
- atria
what are the main locations of M3 (glandular/smooth muscle) Ach receptors?
exocrine glands:
- gastric
- salivary
smooth muscle:
- GI tract
- eye
- airways
- bladder
blood vessels:
- endothelium
what is the cellular response of M1 Ach receptors?
↑ IP3, DAG
what is the cellular response of M2 Ach receptors?
↓ cAMP
what is the cellular response of M3 Ach receptors?
↑ IP3, DAG
what is the functional response of M1 Ach receptors?
gastric secretion
what is the functional response of M2 Ach receptors?
cardiac inhibition
what is the functional response of M3 Ach receptors?
- gastric, salivary secretion
- GI smooth muscle contraction
- ocular accommodation
- vasodilation
what are the pharmacological properties of pilocarpine?
non-selective muscarinic agonist
what are clinical uses of pilocarpine?
- constriction of pupils (miosis)
- glaucoma (to decrease IOP)
- xerostomia (following head/neck radiotherapy)
what are the pharmacological properties of bethanechol?
non-selective muscarinic agonist
what are the pharmacological properties of atropine?
- non-selective agonist
- well absorbed orally
- CNS effects
what type of receptor is a muscarinic receptor?
g-protein linked receptor (metabotropic)
what type of receptor is an nicotinic receptor?
ionotropic
what does acetylcholine have receptor specificity for?
muscarinic and nicotinic
what does nicotine have receptor specificity for?
nicotinic
what does muscarine have receptor specificity for?
muscarinic
what does bethanechol have receptor specificity for?
muscarinic
what does pilocarpine have receptor specificity for?
muscarinic
what are the clinical uses of bethanechol?
bladder and gastrointestinal hypotonia
what are the clinical uses for atropine?
- adjunct for anaesthesia
- anticholinesterase poisoning
- bradycardia/cardiac arrest
what are the pharmacological properties of glycopyrronium?
similar to atropine:
- non-selective agonist
- wel absorbed orally
- CNS effects
- does not cross blood brain barrier
what are the clinical uses of glycopyrronium?
- adjunct for anaesthesia
- anticholinesterase poisoning
- bradycardia/cardiac arrest
what are the pharmacological properties of hyoscine hydrobromide?
similar to atropine:
- non-selective agonist
- wel absorbed orally
- CNS effects
what are the clinical uses of hyoscine hydrobromide?
- hypersalivation
- motion sickness
what are the pharmacological properties of ipratropium?
- delivered via inhaler or nebuliser
- does not cross blood brain barrier
what are the clinical uses of ipratropium?
maintenance treatment of COPD
what are pharmacological properties of tropicamide?
similar to atropine but shorter acting:
- non-selective agonist
- well absorbed orally
- CNS effects
what are clinical uses of tropicamide?
opthalmic use (mydriasis)
why is there little therapeutic uses for agonists?
very few diseases of decreasing parasympathetic activity, more due to increasing activity
what are the general problems of selectivity with antagonists?
- few differentiate between subtypes effectively
- muscarinic ACh receptors widespread; side effects
- control by route of administration and distribution
