drug that blocks cholin transport into the neuron and thereby inhibits the synthesis of acetylcholine

(has no current medical use)

drug that prevents the vesicular storage of acetylcholine

(has no current medical use)

DEMSER

inhibits the synthesis of norepinephrine; a competitive inhibitor of tyrosine hydroxylase

can be used to inhibit norepi and epi synthesis in persons with an adrenal medullary tumor (pheochromocytoma) that secretes large amounts of these substances and thereby causes severe HTN

one of the acetylcholine receptors activated by muscarine

primarily located at parasympathetic neuroeffector junctions

activation of muscarinic receptors on presynaptic autonomic nerves inhibits further neurotransmitter release

M1: primarily concerned with modulation of neurotransmission at central and peripheral sites

M2: activation mediates cardiac slowing

M3: activation produces smooth muscle contraction (except sphincters)

type of acetylcholine receptor activated by nicotine

found in all autonomic ganglia, at somatic neuromuscular junctions, and in the brain;

acetylcholine-gated sodium channels -> when activated leads to sodium influx and membrane depolarization

muscarinic

nicotinic

alpha adrenoceptors

beta adrenoceptors

ocular -> increase lacrimal gland secretion and stimulate contraction of iris sphincter (pupil constriction/miosis)  and ciliary muscles (accomodation to close objects)

repiratory -> stim. increases bronchial muscle contraction, secretion of mucus throughout resp tract

cardiac -> decrease impulse formation in SA node by reducing rate of diastolic depolarization (slowing HR); slow conduction rate of cardiac AP through AV node (increasing PR interval)

vascular -> vasodilation; nitric oxide synthetase is activated forming nitric oxide cuasing vascular smooth muscle relaxation

GI and uro -> stimulate salivary, gastric, and other secretions in GI tract, increase GI smooth muscle contraction (increasing GI motility); stimulate bladder detrusor muscle (minturition)

bind and activate Ach receptors

choline esters, plant alkaloids

can bind to muscarinic and/or nicotinic receptors

increase the synaptic [  ] of Ach by inhibiting cholinesterase -> prevents the breakdown of Ach at all cholinergic synapses

two types: reversible or irreversible cholinesterase inhibitors

or some augment Ach signal transduction (increase cGMP levels)

Ach and synthetic Ach analogues (bethanechol, carbachol)

Ach and carbachol -> activate both muscarinic and nicotinic receptors

bethanechol -> activates only muscarinic receptors

b/c of their lack of specificity for muscarinic receptor subtypes, the muscarinic receptor agonists cause a wide range of effects on many organ systems

bethanechol

carbachol

choline esters of carbamic; resistant to hydrolysis by cholinesterase

bethanechol -> selectively activates muscarinic receptors, used to stimulate bladder and GI muscle w/o significantly affecting HR or BP; don't ever administer IV (can cause hypotension and bradycardia)

carbachol -> effective treatment of chronic opne-angle glaucoma

synthetic direct-acting muscarinic receptor agonist

treat dry mouth and eventually dry eyes

used to treat these conditions in pts who have had radiation therapy for head and neck cancer and in those with sjogrens syndrome

Ach

bethanechol (URECHOLINE)

carbachol

muscarine

nicotine

pilocarpine (SALGEN)

cevimeline (EVOXAC)

varenicline (CHANTIX)