Study Set Content:
Serotonin is metabolized by MAO, and the intermediate
product,
5- droxyindoleacetaldehyde,
Serotonin is metabolized by MAO, and the intermediate
product, 5- droxyindoleacetaldehyde, is further oxidized
by aldehyde dehydrogenase to
5-hydroxyindoleacetic
acid (5-HIAA).
In humans consuming a normal diet, the excretion of (blank) is a measure of serotonin synthesis
5-
HIAA
HIAA is a measure of serotonin synthesis. Therefore, the
24-hour excretion of 5- HIAA can be used as a diagnostic
test for (blank) that synthesize excessive quantities of
serotonin, especially carcinoid tumor.
tumors
A few foods (eg, bananas) contain large amounts of
serotonin or its precursors and must be prohibited during
such
diagnostic tests
The actions of serotonin are mediated through a
remarkably large number of
cell membrane
receptors.
no. families of 5-Ht receptor subtypes
7
Seven families of 5-Ht receptor subtypes (those
given numeric subscripts
1 through 7
no . involving 6 protein-coupled receptors
of the usual 7-transmembrane serpentine type
6
six involving 6 protein-coupled receptors
of the usual 7-transmembrane serpentine type and
one a
ligand gated ion channel.
The latter (blank) receptor is a member of the
(blank), family of Na+ /K+ channel
proteins.
5-HT 3, nicotinic/GABA
Nervous system serotonin
Neurotransmitter
- Precursor of melatonin in the pineal gland.
a 5-HT 1A agonist currently in
clinical trials, appears to have some antinoceciptive
action at a higher doses while reversing opioid-
induced respiratory depression.
Repinotan
in the GI tract and in the
vomiting center of the medulla participate in the
vomiting reflex
5-HT 3 receptors-
They are particularly important in vomiting caused
by chemical triggers such as cancer chemotherapy
drugs. 5-HT 1p AND 5-HT 4 receptors also play
important roles in enteric nervous system function.
5-HT 3 receptors-
receptors also play
important roles in enteric nervous system function. a potent stimulant of pain and itch sensory nerve
endings and is responsible for some of the symptoms
caused by insect and plant stings.
5-HT 1p AND 5-HT 4
is a powerful activator of chemosensitive
endings located in the coronary vascular bed.
serotonin
Activation
of 5-HT 3 receptors on these afferent vagal nerve
endings is associated with the chemoreceptor reflex (also
known as the
Bezold-Jarisch reflex).
The reflex response consists of marked (blank) and
(blank), and its physiologic role is uncertain
bradycardia, hypotension
is mediated by vagal outflow to the
heart and can be blocked by atropine.
bradycardia
