LOADING AWESOME
LOADING AWESOME
ADRENALINE
LOADING AWESOME
ADRENORECEPTORS

www.propofology.com
Dr. David Lyness
@Gas_Craic
AUTONOMIC NERVOUS SYSTEM
ANS = INVOLUNTARY, RAPID, NEURONAL REFLEXES
All A&B receptors are G-protein linked
Alpha-1 = Receptors activate phospholipase C. Action mainly by increasing release of intracellular calcium.
Alpha-2 = Receptors inhibit adenylate cyclase, reducing cAMP formation - mostly presynaptic (others being post)
Beta-1 and -2 = Receptors stimulate adenylate cyclase, increasing cAMP formation.
Alpha-2 = Receptors inhibit adenylate cyclase, reducing cAMP formation - mostly presynaptic (others being post)
Beta-1 and -2 = Receptors stimulate adenylate cyclase, increasing cAMP formation.
Alpha-1: Vasoconstriction,
Gut smooth muscle relaxation
Increased closure of internal bladder sphincter
Salivary secretion,
Glycogenolysis in the liver,
Contraction of gut sphincters and uterus.
Alpha-2: Vasodilatation (central),
Alpha-2: Vasodilatation (central),
Vasoconstriction (peripheral),
Gut smooth muscle relaxation.
Sedative Effect on CNS
Inhibits Insulin Release
Beta-1: Positive inotropy and chronotropy.
Beta-1: Positive inotropy and chronotropy.
Increases oxygen demands of myocardium
RENIN release and thus RAAS stimulated
Beta-2: Vasodilatation in muscle, gut and kidneys
Beta-2: Vasodilatation in muscle, gut and kidneys
Bronchodilatation,
Pupillary dilatation,
Glycogenolysis in muscle and liver
Increases glucagon release
cAMP is synthesised from ATP by ADENYLATE CYCLASE (AC). AC is activated by signalling molecules via G protein coupled receptor and is inhibited by agonists of AC G protein coupled receptors
Liver AC responds more strongly to glucagon, and muscle adenylate cyclase responds more strongly to adrenaline.
If you INHIBIT cAMP like in A2 receptors - you will get less neurotransmitter release and the effects opposite.
If you STIMULATE cAMP like B1&2 - you will get more neurotransmitter release
EPHEDRINE - is a sympathomimetic amine, acts on part of the sympathetic nervous system (SNS). The principal mechanism of action relies on its indirect stimulation of the adrenergic receptor system by increasing the activity of norepinephrine at the postsynaptic α and β receptors.
Noradrenaline inhibits its own release when bound to alpha-2
Adrenaline is a potent agonist at all receptor sites. It will work at A2, but the net effect increases BP and vasoconstriction.
Rate Limiting Step
ADRENALINE
SYNTHESIS
WHERE?
Alpha 1 & 2 = Central and Peripheral Nervous System
Beta 1 = Postsynaptic and are located mainly in the heart but also in platelets, salivary glands and the non-sphincter GI tract
Beta 2 = Mainly postsynaptic. Found in tissues including blood vessels, bronchi, GIT, skeletal muscle, liver and mast cells.
