1. Chapter six
BASIC PHARMACOLOGYOF THE DIRECT-ACTING CHOLINOCEPTOR STIMULANTS

2. The direct-acting cholinomimetic drugs can be divided on the basis of chemical structure into esters of choline (including acetylcholine) and alkaloids (such as muscarine and nicotine).
A few of these drugs are highly selective for the muscarinic or for the nicotinic receptor. Many have effects on both receptors; acetylcholine is typical.

3. Cholinomimetic drugs classify cholinomimetic drugs
Cholinoceptor stimulants
M、NR agonist
Acetylcholine,ACH
MR agonist
Pilocarpine
NR agonist
nicotine
cholinesterase inhibitors
Neostigmine physostigmine

5. M,N receptor agonist acetylcholine 乙酰胆碱
Pharmacological effects
1 Muscarinic effect
1)cardiovascular system:inhibition
decrease in heart rate (negative chronotropy)
decrease in heart contractility (negative inotropy)
decrease in heart conduction velocity (negative dromotropy)
reduction in peripheral vascular resistance
blood vessels (arteries and veins) dilation (via EDRF)

6. Acetylcholin乙酰胆碱 Muscarinic effects
2)eye:
miosis, accommodation of focus for near vision
3)glands secretion increase
sweat, salivary, lacrimal, nasopharyngeal
4)smooth muscle : contraction
bronchial muscle ,gastrointestinal tract , urinary bladder detrusor (voiding)

7. M,N receptor agonist acetylcholine 乙酰胆碱
2 nicotinic effect
to excite ganglia
adrenal medulla secrete Adr
cardiovascular system ↑
smooth muscle ↑
glands secretion ↑
neuromuscular junction ↑

8. Carbamylcholine (carbachol)
M,N receptor agonist
similar to ACH

9. M R agonist—Pilocarpine 毛果芸香碱
active ingredient of poisonous mushrooms
Pharmacological effects
direct agonist
selectively stimulate muscarinic receptors

10. M R agonist Pilocarpine
1 eye:
miosis : sphincter muscle of iris (circular pupillary constrictor muscle) contraction , reduction in pupil size

11. M R agonist---Pilocarpine 毛果芸香碱

13. accommodation of focus for near vision :ciliary muscle contraction

15. reduce intraocular pressure :Ciliary muscle contraction puts tension on the trabecular meshwork, opening its pores and facilitating outflow of the aqueous humor into the canal of Schlemn, increased outflow reduces intraocular pressure

17. 2 Glands secretion increase
sweat, salivary, lacrimal, nasopharyngeal

18. M R agonist---Pilocarpine 毛果芸香碱
Clinical uses
1 glaucoma angle-closure glaucoma type
open-angle glaucoma type
2 iritis together with mydriasis drugs (such as antimuscarinic drugs)，to prevent synechia (adhesion) of iris and lens
3 artropine intoxication

19. M R agonist---Pilocarpine 毛果芸香碱
toxicity
1 Ciliary convulsion (spasm): drops overdosage
2 Depending on absorption: predictable signs of muscarinic excess ( nausea, vomiting, diarrhea, salivation, sweating, cutaneous vasodilation, and bronchial constriction)
prevention: press the canthus of the eye beside the nose