Serotonin Flashcards
What is the precursor to serotonin?
Tryptophan and the rate limiting step is Tryptophan Hydroxylase
Where is melatonin produced at?
Pineal Gland
How is serotonin metabolized?
Monoamine Oxidase
Where is most of the serotonin located in the body?
GI System 90% and the rest is in platelets and CNS. GI has 1 day turnover and CNS has constant turn over
CNS neurons that use serotonin cell bodies are located where?
Raphe Nuclei
What is the type of secondary messengers of serotonin receptors?
All G-protein coupled, except 5-HT3 receptor, which is ligand gated channel.
What are serotonin effects in the GI?
Serotonin causes smooth muscle contraction, which can induce emesis and/or diarrhea.
Serotonin effects on the cardiovascular system?
Vasoconstriction of large vessels both arterial/venous and cranial. Vasodilation of coronary arteries and skeletal muscle.
What is a reflexive (Bezold-Jarisch Reflex) response to serotonin?
Activates the chemoreceptor causing bradycardia, hypotension, and hypoventilation.
What are some conditions serotonin is involved in the CNS?
sensory preception, deep sleep, temp regulation, short term memory, pain, drug abuse, and EMESIS
How is serotonin released from the neuron?
Pumped into vesicle via VMAT and released into the cleft
What drug is a potent hallucinogen?
Lysergic Acid Diethylamide. 5HT2 partial/full agonist.
Anti-Anxiety agent?
Buspirone. partial 5-HT1a agonist
What is Sumatriptan and what is a contraindication?
Treats migraine headaches during and preventatively. 5-HT1D Agonist. Contraindicated if recent MI due to side effect of angina.
What are two ways to increase serotonin in the synaptic cleft?
SSRI - Fluoxetine
MAOI - Phenelzine
