Melatonin Flashcards
What is the Photoregulated enzyme for the ACETYLATED step in Melatonin Synthesis
Seratonin-N-acetyl Transferase
- AANAT
Which one of the following neurons contain Melanopsin?
- ipRG cells
(Intrinsically photosensitive Retinal Ganglion) Cells
Where does Melatonin get produced?
In the PINEAL Gland in the Brain
PVN stands for what?
PARA-Ventricular Nucleus
Another name for Melatonin
Acetylated-Methylated Serotonin
What connection defines the RHT (Retino-Hypothalamic Tract)
- ipRGC to SCN
How do the nuclei communicate with each other?
Via Tracts
Photoentrainment
Light Training
What is the Purpose of the Antioxidant cascade of Melatonin
To Protect Against
- OXIDATIVE Stress
- Free radicals produced by O2 - NITROSATIVE Stress
- Reactive Nitric Oxide
“When OO and NO get together to OONO!!!!”
What is the Coenzyme for the HYDROXYLATION step in Melatonin Synthesis
Tetra-hydro-BIOPTERIN
Melanopsin
- Receptor for photos
- 460nm (Blue light)
- light hits receptor and sets of cascade of effects
Where is the PVN located?
In the HYPOTHALAMUS
Melatonin Synthesis: Reaction steps
Start with Tryptophan
- HYDROXYLATION
- DECARBOXYLATION
- ACETYLATION
- METHYLATION
“Hoover DAM”
Where is the SCN located
- Located in the HYPOTHALAMUS
- Situated Directly ABOVE the Optic Chiasm
- 2 Nuclei
What kind of receptors are on the Pinealocyte?
A/B ADRENERGIC Receptor
What is a Direct Precursor to AMK?
AMFK
What is the Photoregulated enzyme for the METHYLATION step in Melatonin Synthesis?
Acetyl-Serotonin-O-methyltransferase
- ASMT
Fxn of the SCN
- Controls the CIRCADIAN rhythm
(Master Oscillator) - Influences many Physiological and Behavioral Rhythms in 24hr cycle
What gets Produced when Melatonin Reacts with Oxidants/Radicals?
- C-3-OH-Melatonin
- Cyclic-3-Hydroxymelatonin - AFMK
- N-Acetyl-N-Formyl-5-Methoxykynuramine
What is the Neurotransmitter used on the Pineal gland?
Norepinephrine
What Vitamins are ANTIOXIDANTS?
- Vitamin E
- Vitamin C
What does ROS mean?
Reactive Oxygen species
Where is the Intermediolateral Nucleus located?
In the SPINAL CORD
What is the Coenzyme for the DECARBOXYLATION step in Melatonin Synthesis
Vit B6
- Pyridoxo-5-Phosphate
What wavelength of light can be received by the Melanopsin?
460nm
- Blue light
Role of C3OHM and AMFK
- ROS Scavengers
- Lead to formation of AMK
ROS Scavenger as well
What Intermediate does the Norepinephrine act on in the Pinealocyte?
Seratonin
AANT and ASMT
Photo-regulated enzymes in the Melatonin synthesis pathway
Physical route from the Retina to the Pineal gland
- Retinal Ganglion cells
- SCN
- PVN
- Intermediolateral Nucleus
- SCG
- Pineal Gland
SCN stands for what?
SUPRA-Chiasmatic Nucleus
Where does photoentrainment begin with?
INTRINSICALLY Photosensitive Retinal GANGLION Cells
- In the back of the eye
Purpose of Photoentrainment?
Trains us to NOT produce Melatonin
Melatonin Synthesis: Intermediate steps
- Tryptophan
- 5- Hydroxy-tryptophan
- Serotonin
- N-Acetyl-serotonin
- Melatonin
