SECTION II AUTONOMIC DRUGS Chapter 10 Adrenergic agonists Adrenoceptor-activating drugs
SECTION II AUTONOMIC DRUGS Chapter 10 Adrenergic agonists Adrenoceptor-activating drugs
Sympathetic pathway Cholinergic nicotinic receptor ACh Adrenergic receptor (a or b) Adrenergic postganglionic neuron Cholinergic Autonomic ganglion CNS preganglionic NE Target neuron tissue Parasympathetic pathway Cholinergic nicotinic receptor Cholinergic postganglionic Cholinergic muscarinic receptor neuron Cholinergic CNS preganglionic ACh Autonomic ACh Target neuron ganglion tissue
A.Adrenergic transmission 3 Activates Adrenal Inhibits medulla Epinephrine(E) Norepinephrine L-tyrosine Varicosities Bloodstream NE) L-dop阳 B-adrenoceptor 2 1.Tyrosine hydroxylase Inactivated (MAO) CAMP 2.Adenylyl cyclase Dopamine Action potential 3.ATP,substance P PKA NE 6d az-adrenoceptor o2-adreno- 4.Calcium channel ceptor Heart,glands. smooth musde 6c 6b Inactivated: Re absorption by MAo by COMT Norepinephrine (NE) Epinephrine Capillary 6a Diffusion into blood (raises NE in blood) 0- adrenoceptors adrenoceptors P
Norepinephrine (NE) 1.Tyrosine hydroxylase 2.Adenylyl cyclase 3.ATP, substance P 4.Calcium channel
Transmitters and Receptors Mitochondria Synaptic vesicles Synaptic cleft Presynaptic membrane Postsynaptic membrane Scheme showing the ultrastructure of a synapse
Synaptic cleft Transmitters and Receptors
B.Adrenoceptors Norepinephrine Natural agonists Epinephrine Agonists: Phenylephrine Clonidine Iso- Salbu- proterenol tamd Antagonists: Prazosin Yohimbine Atenolol Adrenergic receptors: 2 3 Gg← Go G,← G← PIP2 CAMP CAMP↑ PLCp DAG PKA↑ PK↑ IP3 PKC PKA 公 +a Hyper- Hyper- Dolartzation [Ca2*] [Ca2*3↓ polartzation [Ca2*]h↑ Inhibition of gastrointestinal motility Inhibition of d2 B2 0 exocytosis Drives heart Dilatation of Contraction of d orsecretion ·Vessels ·Blood vessels Salivary glands Bronchioles Bronchioles 。Insulin ·Uterus Sphincters ·Norepinephrine Renin release etc. Uterus ·Acetylcholine etc. etc