Neurotransmitters: Purines

What is a Purine?

A purine comes from purinergic neurotransmission, which is when ATP is released from nerves as either a transmitter or cotransmitter. This is so that it can act as an extracellular signaling molecule on pre-junctional and post-junctional membranes. These are found at neuroeffector junctions and synapses. They also act as a trophic factor in development as well as regeneration.

A purine is a compound and is used to make up the building blocks of both DNA and RNA.

Chemical Makeup

A purine is composed of carbon and nitrogen. It’s molecular formula is C5H4N4. They include adenine and guanine as well, which is how they are able to contribute to DNA and RNA formation. They also include a lot of other biomolecules. This includes ATP, cyclic AMP, NADH, GTP and coenzyme A. A basic model of purine includes nine atoms in its structure

Purine Function

The function of a purine is to provide energy, be a metabolic signal, control cell growth, and they also come together to become essential coenzymes.

Purine Forms

Purines include isoguanine, caffeine, uric acid, theobromine xanthine, and hypoxanthine, Sed eu leo ut risus pharetra gravida. Praesent lacinia mattis sagittis. Integer nec ante scelerisque, posuere dui eu, volutpat nisl. In congue felis at luctus dapibus. Nulla cursus enim nec gravida hendrerit. Proin ut risus libero. In hac habitasse platea dictumst. Nullam a enim felis. Vestibulum mi nibh, auctor a ex a, efficitur auctor orci. Sed at porta nisi. Proin elementum semper nisi, nec mollis massa semper quis. Ut lacinia ut nunc in congue. Suspendisse imperdiet neque in efficitur commodo. Suspendisse imperdiet nibh quis placerat interdum. Etiam mattis risus sit amet nisl faucibus auctor. Quisque fermentum vulputate dui eu aliquam.

Purine Receptors

The figure below represents purine release and metabolism.In this model, ATP is used as a signaling molecule as well as energy. Vesicular nucleotide transporters (VNUT) package ATP into vesicles. This provides their exocytotic release pathway. ATP is rapidly hydrolyzed into adenosine in the extracellular space by ectoenzymes. Purines act through P1, P2x and P2y receptors. Through either equilibrative or concentrative nucleoside transporters (ENT or CNT), adenosine is taken up into cells and metabolized into uric acid or ATP through adenosine kinase and AMP.

References

https://pubmed.ncbi.nlm.nih.gov/31646477/

https://www.britannica.com/science/purine

https://www.sciencedirect.com/science/article/pii/S0753332221000585