Nicotine has a high affinity in what parts of the body?
Skeletal muscle, autonomic ganglia and adrenal medula, spinal cord, brain
Muscurine has a high affinity in what parts of the body?
Smooth muscle of the eye, arterioles, GI, salviary gland cardiac muscle brain
Describe the structure of methacholine and receptor of action.
acetylcholine with methyl only muscarinic
Describe the structure of carbachol and receptor of action.
Acetycholine + amide both nicotinic and muscarinic not susceptible to cholinesterase
Describe the structure of bethanechol and receptor of action
acetycholine + amide + methyl only muscurinic not susceptable to cholinesterase
Do quarternary amines get into the CNS?
They usually never get into the CNS but once in a while they do.
How are muscarinic receptors activated?
Activation ip3, dag, increases of cGMP, inhibition of cAMP, k Channel opening
How is eye stimulated by a cholinergic agonist?
M3 receptor causes contraction of iris sphincter= miosis contraction of the ciliary muscle= lens thickening helps in near vision this allows to the outflow of aqueous humor through the canal of Schlemm
What are some parasympathetic drugs that can affect the eye?
Pilocarpine, Echothiophate Physostigmine
How is the eye stimulated by an adrenergic agonist and what are the drugs?
Contracts the diliatory muscle and dilates the pupil Phenylephrine
What are the effects of B-blocker in the eye?
decreases production of aqueous humor.
What is atropine and what are its effects?
Its a muscarinic antagonist it dilates the pupil and relaxes the ciliary muscle blocks canal of schlemm and precipitates glaucoma. contraindictated with patients with glaucoma!
What are the effects of muscarinic agonists on the heart?
increases K for hyperpolarization in atrial and SA node decreass Ca channel permeability reduction in sodium little effect on ventricles
What are the effects of NO?
muscarinic agonists activate M3 on endothelium smooth muscle and produce vasodilation. Activates cGmp and causes smooth muscle relaxation
What is the mechanism of NO release?
G protein activated -> ip3/dag-> calcium increase -> activates calmodulin -> activates NOS -> phosphorylates arginine to give NO that activates GC -> cGMP and relaxation
What did Dale's show in his four part experiment?
1; little ach produces vasoldialtion and fall in BP 2; little more ach has same effects 3; atropine blocks and ach has no effect 4; add alot of ach after atropine and results in trachycardia ==must be working on nicotinic receptors and m are blocked
What the mechanism of an errection
Ach acts upon muscarinic receptors generating NO Activates GC -> cGMP levels increase relaxes smooth muscle corpus cavernosum and increases inflow of blood
What is the exception on slide 36?
Is ejaculation regulated by para or sympathetic system?
What is viagra mechanism of action?
It is a phosphodiesterase inhibitor. (stops the breaking down of cGMP and cAMP) increases cGMP
How is it determined that an erection is psychological or physiological?
Nocturnal penile turnescence test illustrates physiological vs psychological
What are some phosphodiesterase (PDE) tyoe 5 inhibitors