Purine metabolism

1. METABOLISM OF PURINE
NUCLEOTIDES

2. Origin of the ring atoms of purine

16. Purine bases are recycled from Salvage Path way
Adenine + PRPP AMP+ PPi
Guanine + PRPP GMP+Ppi
Hypoxanthine+ PRPP IMP+PPi
APRT
HGPRT
HGPRT

23. GOUT
Primary Gout:
Enzyme defect
Secondary Gout
1.Over production of Uric acid (Cancer, Starvation,alcohol)
2.Decreased excretion of uric acid (renal failure, Lactic
acidosis, alcohol)

24. GOUT
Symptoms:
Arthritis of Metatarsophalangeal joint
Precipatated by high purine diet & alcohol
Tophi – chronic cases
Treatment:
Decreased purine intake
Allopurinol- xanthine oxidase inhibitor
Probenacid – uricosurics
Colchicine – anti inflammatory

25. LESCH- NYHAN SYNDROME
X – linked disorder
HGPRTase deficiency
Self mutilation, mental retardation, nephrolithiasis

26. PURINE NUCLEOTIDE ANALOGS
Used as Anti cancer agents:
Mercaptopurine
Methotrexate
Azaserine
6-TG (thioguanine)
8 AG (Azaguanine)