DA 5HT & Amino Acids Flashcards
What is the pharmacology of DA?
CNS regulation of movement, attention, reward, behavior, and endocrine function.
What is involved in the synthesis and catabolism of DA?
- Tyrosine hydroxylase, Dopa Decaboxylase
2. VMAT, DAT, MAOb
What are the 4 main brain DA pathways?
- Nigrostriatal (SN –> Striatum)
- Mesolimbic (VTA –> NA, HP, AMY, etc.)
- Mesocortical (VTA –> PFc)
- Tuberoinfundibular.
Which DA receptors are coupled to Gs proteins and what do they do?
D1 & D5
1. Increase cAMP (typically postsynaptic)
Where are D1 and D5 receptors located?
Substantia nigra Striatum Cortex Limbic Hypothalamus Blood vessels Kidneys
Which DA receptors are coupled to Gi proteins and what do they do?
D2, D3, D4-lik receptors
1. Decrease cAMP (presynaptic & postsynaptic)
Where are D2, D3, and D4 DA receptors located?
Substantia nigra Striatum Cortex Limbic Pituitary
What uses do DA receptor agonists have?
Parkinson’s
ADHD
Hyperprolactinemia
Restless Leg Syndrome
What uses do DA receptor antagonists have?
Anti-emtics
Anti-psychotics
Movement disorders (Huntington’s, Tourettes’s, Dystonia’s)
Peripherally what roles does 5-hydroxytryptamine (5-HT) play?
- Storage granules in platelets (aggregation)
- Enteric NS (Peristalsis, nausea/vomiting)
- Blood vessels (microcirculation)
- Cardiac valves
Centrally what roles does 5-hydroxytryptamine (5-HT) play?
- Control of mood, appetite, sleep, nausea/vomiting, nociception.
What are clinical conditions that involve 5HT neurotransmission?
- Migraine
- Anxiety
- Schizophrenia
- Depression
- Nausea and vomiting
- Aggression and Impulsivity
- OCD
- Phobias
Where is 5HT formed?
Raphe Nucleus
What enzymes are involved in forming 5HT?
- Tryptophan Hydroxylase (Tryptophan –> 5-hydroxytryptophan)
- Dopa Decaboxylase (aromatic amino acid D)
What does MAO break 5HT down to?
5HIAA
What enzymes are involved in melatonin formation. What is it formed from and where?
- 5HT N-acetyltransferase
- 5-hydroxyindole-O-methyltransferase
From 5HT and in Pineal Gland.
Where are B1, B2, B3 located?
Raphe Magnus
Where is B4 located?
Raphe Obscurus
Where are B5, B8, B9 located?
Medial Raphe
Where is B6, B7 located?
Dorsal Raphe
Where are melatonin receptors located?
SCN, Anterior Pituitary, Periphery.
The 5HT1 receptor is coupled to what G protein?
GI –> Decreases cAMP.
The 5HT2 receptor is coupled to what G protein?
Gq –> Increase IP3/DAG
Other 5HT receptors (not 5HT1, 5HT2) are coupled to what G protein?
Gs –> Increase cAMP.
What is the Serotonergic Syndrome?
- Toxic, potentially fatal effects of combined drugs.
2. Wide range of central and peripheral adverse responses.