5.1 Cholinergic

Question 1

What receptor type is found only in nerves?

Answer 1

M1

Question 2

What receptor is found in nerves, the hearts, and smooth muscle?

Answer 2

M2

Question 3

What receptor type is found in glands, endothelium, and smooth muscle?

Answer 3

M3

Question 4

What receptor is found only at the neuromuscular junctions?

Answer 4

Nm

Question 5

What receptor is found in the CNS, Post-ganglionic cell body/dendrites?

Answer 5

Nn

Question 6

How do muscarinic receptors get the signal into the cell?

Answer 6

G-membrane linked

Question 7

How do nicotinic receptors get the signal into the cell?

Answer 7

Voltage-gated

Question 8

In the CNS, what is the mechanism A2 receptors use for their effect?

Answer 8

Control Ca++ release

Question 9

What catalyzes hydrolysis of ACh?

Answer 9

AChE

Butyryl-ChE (in plasma)

Question 10

What are the cardiac effects of ACh?

Answer 10

Vasodilation
↓ HR (negative chronotropic effect)
↓ conduction velocity (negative dromotropic effect)
↓ force of cardiac contraction (negative inotropic effect)

Question 11

What are the respiratory effects of ACh?

Answer 11

Regulating bronchomotor tone
Bronchoconstriction
↑ tracheobronchial secretion

Question 12

What are the urinary effects of ACh?

Answer 12

Detrusor muscle contraction
↑ increase voiding pressure
Ureteral peristalsis

Question 13

What are the GI effects of ACh?

Answer 13

↑ GI motility, tone
↑ amplitude of contractions
↑ secretory activity of stomach and intestine

Question 14

What are the HEENT effects of ACh?

Answer 14

↑ lacrimation, nasopharyngeal, and sweat glands secretion
↑ salivary secretion
Contraction of pupillary sphincter muscle miosis
Contraction of ciliary muscle

Question 15

What is a cholinomimetic?

Answer 15

Drug that mimics the actions of ACh

Question 16

What is the mechanism of a direct agonist cholinomimetic?

Answer 16

Directly binds to ACh receptor

Question 17

What is the mechanism of an indirect cholinomimetic agonist?

Answer 17

Affect metabolism of breakdown of ACh

= affects AChE

Question 18

What type of cholinomimetic are Esters of choline and Alkaloids?

Answer 18

Direct cholinomimetic

Question 19

What is the mechanism of Esters of choline?

Answer 19

Structure has charged quaternary ammonium group
Poor lipid soluble poorly absorbed  poorly distributed into CNS
All hydrolyzed in GI – Less active
Differ in susceptibility to hydrolysis

Question 20

What is Miochol-E used for?

Answer 20

Ester of choline

Cataract surgery– intraop only – induce miosis – intraoccular inj. Or topical

Question 21

What is Methacholine (Provocholine) used for? Contraindications?

Answer 21

Mix powder w/ NS and inhale via neb
Diagnostic test – bronchial hyperresponsiveness
Asthma vs. COPD asthmatic pts produce intense bronchoconstriction
Contraindications: limited airflow; MI, stroke, uncontrolled HTN, and pregnancy
Emergency resuscitation, O2, Beta-2 agonist should be available during testing

Question 22

What is Carbachol used for?

Answer 22

Catarac surgery – intraoccular inj or topical – induce miosis or prevent elevated IOP (intraoccular pressure)
Eye drop – no longer available in US – Open angle glaucoma

Question 23

What is Bethanechol (Urecholine) used for? Contraindications?

Answer 23

Urinary tract – Increase detrusor muscle tone
Indications: urinary retention, inadequate emptying w/o obstruction, neurogenic bladder
Dose: 10-50mg PO TID – QID empty stomach to avoid vomiting
GI tract – stimulates peristalsis; motility; increase resting LES (lower esophageal sphincter) pressure
Indications: GERD, post-op abd distention, gastroparesis…
Caution: bradycardia, hypotension, seizure
Contraindications: Asthma, COPD, urinary or GI obstruction, CVD
Hyperthyroidism + muscarinic agonists a. Fib