7: Autonomic Pharmacology II Flashcards
What binds to nicotinic receptors?
Acetylcholine (ACh)
Where are nicotinic receptors found?
Autonomic ganglia (both sympathetic and parasympathetic)
Skeletal muscle
Nicotinic ACh receptors are made up of five different ___.
subunits
The entry of which ion triggers neurotransmitter release from pre- and post-sympathetic ganglia?
Ca2+
What are the two types of ACh receptor?
Nicotinic (symp + parasymp among many other places)
Muscarinic (parasymp only + many other places)
Which types of cholinergic receptor may cause a cellular response?
Nicotinic
Muscarinic
i.e the only two types of ACh receptor
Which type of ACh receptor causes a cellular response at parasympathetic junctions?
Muscarinic
parasympathetic nervous system only
What does M1 receptor activation cause?
Increased gastric acid secretion
What does M2 receptor activation cause?
Decreased heart rate
What does M3 receptor activation cause?
Bronchoconstriction
bronchial smooth muscle constriction
What does ß1 activation cause?
Increased HR and force of contraction
What does ß2 activation cause?
Bronchodilation
Vasodilation
What does α1 activation cause?
Vasoconstriction
What does α2 activation cause?
What kind of physiological control mechanism is this?
Inhibition of NA release
Negative feedback
α2 receptors are sometimes found before the synapse - what implication does this have?
α2 receptors inhibit NA release
Reduce the amount of NA released by negative feedback (excessive NA release triggers more α2 receptors)
Cocaine (stimulates / inhibits) NA release resulting in (increased / decreased) adrenoceptor stimulation.
stimulates , increased
Cocaine’s tendency to increase NA release causes vasoconstriction and cardiac arrythmia.
Why?
NA activates:
α1 adrenoceptors ► vasoconstriction
ß1 adrenoceptors ► increased HR and force of contraction
Which drug, commonly used in treatment of ADHD, has similar effects on NA release and adrenoceptor activation as cocaine?
Amphetamine
Which class of drugs block the adrenoceptors responsible for vasoconstriction, and what are these adrenoceptors?
Alpha blockers (e.g prazosin)
α1 adrenoceptors
Which class of drug blocks cardio-selective adrenoceptors to treat angina and hypertension?
Which adrenoceptor does this refer to?
Beta blockers (e.g atenolol)
B1 adrenoceptors
Which inhaled medication binds to adrenoceptors to cause bronchodilation in asthma?
Which adrenoceptor is this?
SABAs/LABAs (e.g salbutamol / salmeterol)
ß2 adrenoceptors
Which drug non-selectively blocks all muscarinic receptors and is used to treat bradycardia?
Atropine
