Nicotinic receptors

NM NN Central N

Location Skeletal NMJ post synaptic

All autonamic ganglia and adrenal medulla

Sensory nerve terminals presynaptically

Function Contraction of Sk. muscle

NE & E from adrenal medulla

Facilitate release of Dopamine, glutamate

Mechanism Ligand gated channel

Ligand gated channel

Acetyl Co enzyme A and Choline.

M1 (Neuronal and gastric)

M2 (Cardiac) M3(Glandular) M4 M5

Distribution

Ganglia, gastric parietal cells, CNS (cortex, hippocampus)

Myocardium, smooth muscle, presynaptic PNS,CNS

Exocrine glands, visceral smooth muscle, vascular endothelium

Neostriatum Substantia nigra

Function

Gastric acid secretion, GI motility, CNS excitation

SA node rate of impulse generationAV node velocity and decrease atrial and ventricular contraction

Exocrine secretions. Smooth muscle contraction (expect urinary, Blood vessels

- -

Mech G protein (Gq), IP3,DAG,depolarization

Gi cAmp, opening of K+ channels

G protein (Gq), IP3,DAG,depolarization

Gi cAmp, opening of K+ channels

G (Gq), IP3,DAG,depolariz

Agonist

Oxotremorine Methacholine Bethanechol - -

Anta gonist

Pirenzepine, Telenzepine

Methoctramine,Tripitramine

4-DAMP, Hexa hydrosiladifenidol

CENTRAL NERVOUS SYSTEMBrain

PARASYMPATHETIC

Spinalcord

Stimulates salivation VII

Constricts bronchi X

Slows heartbeat X

Stimulates activity

Contracts bladder

Stimulates erectionof sex organs S

Stimulates gallbladder

Gallbladder

Contracts pupil III

Parasympathomimetics

Directly acting Indirectly acting 1. Ach2. Synthetic choline esters Reversible Irreversible

Methacholine CarbamatesCarbachol 1. Natural alkaloids 1. OrganophosphatesBethanechol

3. Natural alkaloids 2. Quaternary

4.Miscellaneous 2. Carbamates

Acridine Tacrine

• Edrophonium• Neostigmine• Pyridostigmine• Ambenonium• Demecarium• Rivastigmine • Popoxour

• Carbaryl• Tremorine• Oxotremorine

• Muscarine• Nicotine• Pilocarpine• Arecoline

• Physostigmine • Ecothophate• Isoflurophate• Paraoxon• Parathion• Malathion• Diazon

Anger, Alert,

Aggressive

Flushing of Face

Bronchodilatation

Mydriasis

In. Cardiac output

Inc. Muscle tone

Lipolysis-Energy

Liver GlucogenolysisMore energy prod

Large B vessels dilate to speed up blood flow

Tyrosine→Dopa→Dopamine→NEpi→Epi