1. Dopamine AND PD

2. Introduction Belongs to the family of catecholamine's
Dopamine can be further converted into the hormones epinephrine and norepinephrine (also catecholamine’s)
Plays a role in regulation of hormones, motor control and learning
Found in humans, animals- both vertebrates and invertebrates

3. Production
Produced in the substantia nigra and the ventral tegmental area
It is a neurohormone and is released by the hypothalamus

4. Dopamine Receptors Two classes:
D1-like receptor class - D1 (locomotion, reward, etc.) and D5 (Learning and memory) receptor subtypes
Activates adenylyl cyclase which leads to increase in concentration of cAMP
D2- like receptor class – D2 (locomotion, learning, etc.), D3 (cognition and emotion) and D4 (mostly unknown, possibly cognition) receptor subtypes
Inhibits adenylyl cyclase leading to decrease in concentration of cAMP
Have similar signaling properties, however have different signal transduction pathways
They are G protein-coupled receptors, signaling mediated by interaction with GTP- binding proteins

5. Dopamine Pharmacology
Can be used as an injectable drug
Intropin, Dopastat, Revimine
used in the treatment of severe hypotension, bradycardia (slow heart rate), circulatory shock, or cardiac arrest
Toxicty-LD50-59mg/kg

6. L-DOPA
Levodopa- dopamine precursor to treat Parkinson’s Disease and dopa-responsive Dystonia
Typically co-administered with an inhibitor of peripheral decarboxylation
Inhibitors of alternative metabolic route for dopamine by catechol-O-methyl transferase are also used
These include entacapone and tolcapone.

7. Psychostimulants
Cocaine and substituted amphetamines all increase dopamine neuronal activity
These use different mechanisms than L-DOPA
Cocaine- dopamine transporter and norepinephrine transporter blocker

8. Antipsychotic Drugs
A range of drugs that reduce dopamine activity have been found useful in the treatment of schizophrenia and other disorders
I.E. Valium

9. Role in Parkinson's Disease
Parkinson's Disease has been related to the loss of dopamine secreting neurons in the midbrain called the substantia nigra.
The projection of dopamine neurons from the substantia nigra pars compacta to the dorsal striatum plays a significant role in the control of motor function and in learning new motor programs. These neurons are especially vulnerable to damage and when a large fraction of them die, the result is PD.
The administration of L-DOPA, the metabolic precursor for dopamine, is a treatment that cannot restore the dopamine cells that have been lost, but causes the remaining cells to produce more dopamine to compensate for what's lost.

10. Help Received
Wikipedia