Study Set Content:
Independent studies established the existence of a smooth
muscle stimulant in intestinal mucosa. This was called
enteramine.
Serotonin or
(5-Hydroxytryptamine)
The synthesis of 5-hydroxytryptamine in 1951 led to the
identification of serotonin and enteramine as the same
metabolite of
5-hydroxytryptophan.
Serotonin is an important neurotransmitter, a local hormone
in the gut, a component of the platelet clotting process, and
is thought to play a role in migraine headache and several
other clinical conditions, including
carcinoid syndrome.
is an unusual manifestation of carcinoid
tumor, a neoplasm of enterochromaffin cells.
carcinoid syndrome.
In patients
whose tumor is not surgically resectable, a (blank) may constitute a useful treatment.
serotonin
antagonist
DISTRIBUTION/SOURCE:
• Plant and animal tissues
• Venoms
• Stings
Synthesized in biologic systems from the amino acid
L-
tryptophan
Synthesized in biologic systems from the amino acid L-
tryptophan by (blank) of the indole ring
hydroxylation
followed
by (blank) of the amino acid.
decarboxylation
In the pineal gland, serotonin serves as a
precursor of(blank), a melanocyte-stimulating
hormone.
melatonin
In mammals (including humans), over 90% of the
serotonin in the body is found in (blank) in the gastrointestinal tract.
enterochromaffin
cells
In the blood, serotonin is found in (blank)
which are able to concentrate the amine by means
of an (blank)), similar to that in the membrane of
serotonergic nerve endings.
platelets,active serotonin transporter mechanism
(SERT
Once transported into the platelet or nerve ending,
5-HT is concentrated in(blank)by a (blank) that is blocked by
reserpine an adrenergic blocking agent.
vesicles
vesicle-
associated transporter (VAT)
Serotonin is also found in the (blank), which contain cell bodies of
serotonergic neurons that synthesize, store, and
release serotonin as a transmitter.
raphe nuclei of the
brainstem
Stored serotonin can be depleted by (blank) in
much the same manner as this drug depletes
catecholamines from vesicles in adrenergic nerves
and the adrenal medulla.
reserpine
(blank) are involved in numerous
diffuse functions such as mood, sleep, appetite, and
temperature regulation as well as the perception of
pain, the regulation of blood pressure, and
vomiting.
Brain serotonergic neurons
Serotonin also appears to be involved in clinical conditions
such as
depression, anxiety, and migraine.
are also found in the enteric nervous
system of the gastrointestinal tract and around blood
vessels.
Serotonergic neurons
Serotonin is metabolized by
MAO
