[PCOL-SEMIS-01-PT9] AUTACOIDS: SEROTONIN

THIS FLASHCARDS IS ABOUT [PCOL] SEROTONIN.

1. Enterochromaffin-like Cells

2. GIT (specifically in the small intestine)

Serotonin are produced in (1)__________ which are found in (2)_____.

90% of 5-HT

The GIT (Small Intestine) synthesize what % of serotonin?

Active uptake

5-HT undergoes ________ into the platelets.

10% of 5-HT

The CNS synthesize what % of serotonin?

Pre-synapse

This is where the synthesis of serotonin takes place.

Tryptophan hydroxylase

Pre-synapse synthesis: Tryptophan, an amino acid catalyzed by what enzyme?

1. 5-Hydroxy-Tryptophan

2. Aromatic amino acid decarboxylase

Pre-synapse synthesis: The intermediate product upon catalyzation of tryptophan is (1)_________, which is also a substrate for the (2)_____.

5-Hydroxy-Tryptamine (5-HT)

Pre-synapse synthesis: There is decarboxylation reaction thus producing serotonin, also known as?

Vesicular monoamine transporter (VMAT)

(Allows serotonin to enter the vesicle to avoid the pre-mature metabolism)

Pre-synapse storage: The serotonin undergoes vesicular storage process via?

1. Calcium ion

2. Vesicles

3. Exocytosis

Pre-synapse release: The (1)________ enters via voltage-gated ion channel, signals the (2)_____ to attach the docking proteins, thus initiating the release of serotonin via (3)______.

1. Post-synaptic receptor

2. Serotonergic effect

1st Fate: The cleft binds to the (1)______ receptor enhancing the (2)_____ effect.

Metabolism

2nd Fate: They will undergo?

Monoamine oxidase (MAO)

What are the enzymes present in the cleft?

• Serotonin

• Dopamine

• Norepinephrine

Monoamine oxidase metabolizes the?

Hint: SDN

Low

If there is metabolization, the level of serotonin in the cleft is?

Reuptake process

3rd Fate: If it’s in the cleft, it undergoes (1)_____ process which is the major fate of serotonin (5-HT).

Plasma membrane serotonin transporter (SERT)

The serotonin can re-enter the pre-synapse and be stored again via the?

Supplemental Info Only

The number of serotonin (5-HT) level is low in the cleft if it reuptakes.

MAO_A

What enzyme metabolizes the serotonin (norepinephrine, epinephrine) inside the pre-synapse?

MAO_B

This enzyme can only metabolize dopamine.

Transmitted

When it reached the post-synapse and it binds to the receptor, meaning the impulse is?