Question

I have to write about adrenaline and histamin

- I should talk about their synthesis- (physiologic mechanisms and drugs or foods affecting them);

- storage in vesicles (physiology-like the name of the pump for storage and drugs, toxins or foods that interferes with it);

-there release-physiology and drugs or toxins that interfere;

-the termination of effect in the synapse (physiology-like enzymatic breakage or re-uptake

-about the drugs that affect the process -and its receptors of these neurotransmitters and drugs acting on these receptors

- refer them as agonists and antagonists for relevant receptors).

I still have 1 more, I will post the question individually

no need for figures if everything I asked for is explained clearly.

Answer 1

Adrenaline

Synthesis

• Site - Adrenal medulla and neurons of the medulla oblongata
• substrate - it is synthesized from phenylalanine and tyrosine
• It is stored in chromaffin granules
• Synthesis is enhanced by the ACTH secretion

The stimulus for release -

• Stress
• Excitement
• Noise
• Bright light

The channels involved in the release

• the sympathetic system stimulated the adrenal medulla via the splanchnic nerves
• the stimulation of the cells of the medulla causes activation of voltage-gated Ca channels
• This leads to calcium influx and release of adrenaline

Site of action :

• Adrenaline acts on adrenergic receptors alpha (1, 2) and Beta (1, 2)
• At the postsynaptic end of the sympathetic postganglionic nerves

termination of action

• Reuptake is the nerve ends
• metabolized by mono-amino oxidase and catechol - O - methyltransferase

Drugs:

1. Sympathetic agonist - these drugs act on the receptors of adrenaline and mimick its effect
   1. example - salbutamol, terbutaline
2. Sympathetic antagonists - these drugs block adrenergic receptors and produce an effect opposite of adrenaline. Example - Propanolol, prazosin
3. Noradrenaline reuptake inhibitors - these are antidepressant drugs - duloxetine

Histamine

Synthesis:

1. it is synthesized from histidine
2. the enzyme required is histidine decarboxylase

Storage -

1. Basophils
2. Mast cells
3. enterochromaffin-like cell of the stomach

The stimulus for release -

1. Allergens like pollen grains, dust mites
2. Plays an important role in gastric acid production

Site of action :

1. it acts on histamine receptor
   1. H1 - tuberomammillary nuclei, smooth muscles
   2. H2 - dorsal striatum, hippocampal, dentate nucleus
   3. H3 - central nervous system
   4. H4 - basophils and bone marrow

termination of action - Histamine - N - methyltransferase degrade histamine

Drugs: Histamine receptor blockers are used as an antacid - like ranitidine, cimetidine