What stimulates the secretion of the CA's?
An action potential
An increase in Noradrenaline
Nerve damage
Once the membrane has been depolarised, what voltage gated channels open?
Sodium
Calcium
Potassium
The influx of ions into the cell signals secretion by exocytosis
What is stored in Catecholamine vesicles, along with the CA?
ATP
ADP
Fromogranin
Chromogranin
ATP is -ve at body pH, whilst CA's are +ve
Why are CA's stored with these other substances?
They keep the CA's out of solution
They keep the CA's in solution
Which helps prevent vesicle lysis due to osmotic pressure
ATP can also act as a neurotransmitter
When concentrations of CA in the synapse are low, Alpha2 Adrenergic receptors are activated,
B2 receptors _ adenylate cyclase, which _ the production of cAMP, which _ the influx of ions
Stimulates, increases, increases
Stimulates, increases, decreases
Inhibits, increases, increases
Inhibits, decreases, decreases
A2 adrenergic receptors have the opposite effect of B2 adrenergic receptors
Re-uptake Method 1 is presynaptic, and mediated by what?
Active transport
Diffusion
A Na+/K+ pump
Na+ channel
Uptake Method 2 is extraneuronal and is used to...
Destroy excess adrenaline
Secrete adrenaline into the bloodstream
Stimulate separate neurones
Monoamine oxidase is found in the RER and interacts with cytoplasmic neurotransmitter
What is the role of monoamine oxidase (3 steps)?
Converts the amine --> aldehyde
Reduction of Aldehyde --> Acid
Reduction of Aldehyde --> Alcohol
Which enzyme uses S-Adenosty Methionine to methylate Neurotransmitters?
Monoamine Oxidase
Catcheol-O-Methyl Transferase
Catecholamine Methylase
What is the final produce of the Oxidative pathway of Monoamine Oxidase?
VMA
MOPEG
What is the final produce of the Reductive pathway of Monoamine Oxidase?
In peripheral tissue, the oxidative pathway predominates. In the brain, the reduction pathway predominates.
