Peripheral Nervous System Pharmacology 1

Question 1

What receptors doe the sympathetic and parasympathetic systems use to act on the kidney? What is their respective effects?

Answer 1

D1 activation causes vasodilation and increased blood flow/GFR
B1 activation stimulates renin release from the kidney

Question 2

What receptors doe the sympathetic and parasympathetic systems use to act on the bladder? What is their respective effects?

Answer 2

M3 activation causes contraction of bladder detrusor and relaxation of trigone (urination)

B2 activation relaxes detrusor
a1 activation constricts trigone and sphincter (urinary retention)

Question 3

What receptors doe the sympathetic and parasympathetic systems use to act on the penis? What is their respective effects?

Answer 3

M3 activation causes relaxation of vessels via action of ACh which causes NO release

a1 activation causes contraction of seminal vesicles, prostitc capsule and vas deferens in ejaculation

Question 4

What receptors doe the sympathetic and parasympathetic systems use to act on the uterus? What is their respective effects?

Answer 4

B2 activation relaxes the uterus

in pregnancy
M3 activation contracts uterus and
a1 activation contracts uterus

Question 5

What are the typical receptors activated by bodily secretions?

Answer 5

M3 activation causes watery secretion (salivary, nasopharyngeal, pulmonary, GI and eccrine sweat

a1 activation stimulates apocrine sweat glands; viscous salivary secretions

Question 6

What are the effects of receptors (which?) on the body’s metabolism?

Answer 6

a2 activation causes a decrease in insulin release

B2 activation promotes glycogenolysis and gluconeogenesis in liver; glycogenolysis and K+ uptake in skeletal muscles and increase in insulin release

B3 activation stimulates lipolysis in adipocytes

Question 7

Which bodies sites have primarily sympathetic activity as the predominant tone?

Answer 7

arterioles, veins (vasculature)- adrenergic

sweat glands - cholinergic

Question 8

Describe the two classes of cholinergic drugs that are used to modulate Acetylcholine activity.

Answer 8

cholinomimetic drugs (mimic ACh activity): agonists at M and N receptors and blocking AChE

cholinolytic drugs (inhibit ACh activity): antagonists at M and N receptors, and one that reactivates AChE

Question 9

Contrast the shape of nicotine and muscarine receptors and the effect on Acetylcholine on both.

Answer 9

nicotinic and muscarinic receptors are both cholinergic receptors in that they respond to Acetylcholine but they are specific to nicotine and muscarine respectively (shows some specificity)

Question 10

Carbachol (Miostat)

Answer 10

agonist at muscarinic receptors with significant Nn activity

used in obtaining mitosis and reducing IOP elevation

precautions: widespread side effects on cholinergic receptors: bradycardia, asthma, hyperthyroidism (already sensitive to catecholamines) peptic ulcer, urinary tract obstruction and parkinsonism

Question 11

Methacholine

Answer 11

agonist at muscarinic receptors with slight nicotinic activity

used in diagnosis of airway hyperactivity, administered by inhalation via nebulizer, very resistant to ACh degradation

precautions with widespread muscarinic activation

Question 12

Bethanechol (Urecholine)

Answer 12

muscarinic agonist with no nicotinic activity

used post op for promoting GI and urinary bladder motility or atony of urinary bladder or stomach

not susceptible to AChE activation; precautions with increasing body wide muscarinic activity

Question 13

Pilocarpine (Piloptic)

Answer 13

muscarinic agonist

particularly active on sweat, salivary glands and eyes (esp for xerstomia caused by Sjorgren’s syndrome); causes miosis and second line tx for open or closed angle glaucoma by causing cilia muscle to contract