Adrenergic reveiw stuff

Question 1

Describe the synthesis of Catecholamines

Answer 1

• Most symapthetic postganglionic neurons, NOREPINEPHRINE IS FINAL PRODUCE

–> EXCEPT: adrenal medulla and certain areas of brain (norepinephrine –> epinephrine)

–> dopaminergic nerouns, synthesis termiantes with dopamine

• RATE LIMITING STEP:

–> Tyrosine –> DOPA

–> INHIBITED BY METYROSINE

Question 2

Describe the storage of adrenergics and what inhibits it

Answer 2

• catecholamines are transported into vesicles via VESICULAR MONAMINE TRANSPORTER (VMAT)
• INHIBTED BY RESERPINE

–> causes depletion of transmitter stores (decreased NT in synapse)

Question 3

Describe Botulinum toxin on catecholamine release

Answer 3

• Botulinum toxin inhibits the release of VESICLES through acting on proteins like SNAP etc

Question 4

Describe the mechanisms for termination of action

Answer 4

• simple diffusion

–> catecholamiens diffuse into CIRCULATION and METABOIZED by Catechol-O-Methyl transferase (COMT)

• Reputake proteins

Question 5

describe the neuronal reuptake of Norepinephrine

Answer 5

• Taken up by norepinephrine transporter (NET)
• INHIBITED BY COCAINE and tricyclic antidepressants drug

–> results in an INCREASE of TRANSMITTER ACTIVITY IN SYNAPTIC CLEFT

Question 6

How are catecholamines metabolized

Answer 6

• Catecholamines are metabolized my monoamine oxidase (MAO)
• INHIBITORS OF MAO such as PHENELZINE result in INCREASE AMOUNT OF CATECHOLAMINES RELEASED

–> MAO-A = metabolizes norepeinphrine, 5-HT, tyramine

–> MAO-B = metabolizes dopamine

Question 7

describe the autonomic cardiovascular function loop

Answer 7

Question 8

describe the autonomic effectsof decrease in blood pressure.

Answer 8

• Decrease in blood pressure –> decrease in baroreceptor discharge –> Increase SANS and decrease PANS
• SANS results in increase HR, contractile force and venous tone
• -> Increase HR –> increase cardiac output
• -> Increase contractile force –> increase stroke volume
• -> Increase venous tone –> increase venous return
• All of which INCREASES MEAN ARTERIAL PRESSURE

Question 9

dsecribe the autonomic effects if there is a increase in blood pressure

Answer 9

• Increase in blood pressure –> increase in baroreceptor discharge –> Increase in PANS and Decrease in SANS

–> PANS results in INCREASE IN VAGAL TONE –> Decrease in HR and a resulting decrease in blood pressure