Diet and purinesDiet and purines

Prof David PerrettProf David Perrett

William Harvey Research InstituteBarts & the London School of Medicine

You are what you eat! You are what you eat!

or or

Gout Gout

A disease of good living ?

A disease of lifestyle?

What are you made ofWhat are you made of

ProteinFats

CarbohydratesOligonucleotides

Inorganic materials and of course Waterand of course Water

70% of your body is water

Reference Man

Reference Woman

Body Composition Methods• Direct Assessment - Cadaver (Dissection v chemical analyses)

Body Composition of 5 Cadavers

60

17

18

5

10

0 10 20 30 40 50 60

Water

Protein

Fat

ASH

Remainder

Percent Body Weight

Gross Composition of Human Body

Body composition analysis often focuses on the tissue and whole body levels of multi-component model.

ProteinProtein

Fats - LipidsFats - Lipids

SugarsSugars

Bread also contains yeast

WaterWater

Nucleic acids and purinesNucleic acids and purines

We eats these as We eats these as

DNA and RNA DNA and RNA

Purine bases Purine bases IMP and possibly ATP

Ischemic catabolites Ischemic catabolites e.g. Hypoxanthine, urate

Minor NutrientsMinor Nutrients

VitaminsVitaminsMetalsMetals

Co-enzymesCo-enzymes

DigestionDigestionLarge molecules must be broken down to smaller moleculesLarge molecules must be broken down to smaller molecules

Then they can pass through the gut and enter the blood streamThen they can pass through the gut and enter the blood stream

Then they can enter cells where some molecules can be directlyThen they can enter cells where some molecules can be directlyused for macromolecule synthesis others will enter metabolic used for macromolecule synthesis others will enter metabolic processes.processes.

Some of the individual protein units (amino acids) cannot be made by the body and are said to be essential.

Not the case with purines and pyrimidines

Nucleic acids and purinesNucleic acids and purines

Purines and pyrimidines can be made by our bodies.

This de novo synthesis takes a lot of energy so nature tries to re-use the purine and pyrimidine ring structures for ATP, etc and DNA & RNA synthesis.

Nucleic acids and purinesNucleic acids and purinesAdenosine triphosphate (ATP) – our energy metabolite

ATP is essential for every breath we takeATP is essential for every breath we take

Partial Metabolic Pathway for ATP degradation ATP

AMP

IMP

Hypoxanthine

Xanthine

5’NTHPRTase

Xanthine Oxidase

Urate

Adenosine

Inosine

Xanthine Oxidase

DNA

HypoxanthineHypoxanthine

Increases in food on storageRelated to the taste of meat and meat

Plant PurinesPlant Purines

TheobromineTheobromineCaffeineCaffeine

Tea, coffee, Tea, coffee, Also soft drinksAlso soft drinks

ChocolateChocolate

Gut BacteriaGut BacteriaThe average human consists of ca. 1013 (ten trillion) cells.

We have about ten times that number of microorganisms in our gut.

There's an estimated 500 different bacterial species in the intestine.

The metabolic activity performed by these bacteria equal to that of a virtual organ making the gut bacteria a "forgotten" organ.

E. ColiE. Coli

Seoul – South Korea 2007