Inosine
89111
220539077
2008-06-20T10:30:08Z
213.170.46.90
/* Clinical significance */
{{drugbox
| IUPAC_name = Inosine
| image = Inosine.svg
| CAS_number = 58-63-9
| ATC_prefix = D06
| ATC_suffix = BB05
| ATC_supplemental = {{ATC|G01|AX02}}
| PubChem = 6021
| DrugBank = EXPT02378
| C=10|H=12|N=4|O=5
| molecular_weight = 268.229 g/mol
| bioavailability =
| protein_bound =
| metabolism = [[Liver|Hepatic]]
| elimination_half-life =
| pregnancy_category =
| legal_status = OTC
| routes_of_administration =
}}
'''Inosine''' is a [[nucleoside]] that is formed when [[hypoxanthine]] is attached to a [[ribose]] ring (also known as a [[ribofuranose]]) via a β-N<sub>9</sub>-[[glycosidic bond]].
Inosine is commonly found in [[tRNA]]s and is essential for proper translation of the genetic code in [[wobble base pair]]s.
Knowledge of inosine metabolism has led to advances in [[immunotherapy]] in recent decades. Inosine monophosphate is oxidised by the enzyme inosine monophosphate dehydrogenase yielding xanthosine monophosphate, a key precursor in [[purine]] metabolism. [[Mycophenolate mofetil]] is an anti-metabolite, anti-proliferative drug, used in the treatment of a variety of [[autoimmune]] diseases including [[Wegener's granulomatosis]]. The uptake of purine by actively dividing [[B cell]]s can exceed 8 times that of normal body cells and therefore this set of white cells (which cannot operate purine salvage pathways) is selectively targeted by the purine deficiency resulting from IMD inhibition.
==Reactions==
[[Adenine]] is converted to [[adenosine]] or [[Inosine monophosphate|IMP]], either of which in turn is converted into inosine (I), which pairs with Adenine (A), [[cytosine]] (C) and [[uracil]] (U).
[[Purine nucleoside phosphorylase]] intraconverts inosine and [[hypoxanthine]].
Inosine is also an intermediate in a chain of purine nucleotides reactions required for muscle movements.
==Clinical significance==
It was tried in the seventies in eastern countries for improving athletic performance. Nevertheless the clinical trials for this purpose showed no improvement.<ref>{{cite journal |author=McNaughton L, Dalton B, Tarr J |title=Inosine supplementation has no effect on aerobic or anaerobic cycling performance |journal=International journal of sport nutrition |volume=9 |issue=4 |pages=333–44 |year=1999 |pmid=10660865 |doi=}}</ref>
Nowadays, it has been shown that inosine has neuroprotective properties. It has been proposed for spinal cord injury;<ref>{{cite journal |author=Liu F, You SW, Yao LP, ''et al'' |title=Secondary degeneration reduced by inosine after spinal cord injury in rats |journal=Spinal Cord |volume=44 |issue=7 |pages=421–6 |year=2006 |pmid=16317421 |doi=10.1038/sj.sc.3101878}}</ref>, because it improves axonal rewiring, and for administration after [[stroke]], because observation has shown that axonal re-wiring is encouraged.<ref>{{cite journal |author=Chen P, Goldberg DE, Kolb B, Lanser M, Benowitz LI |title=Inosine induces axonal rewiring and improves behavioral outcome after stroke |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue=13 |pages=9031–6 |year=2002 |pmid=12084941 |doi=10.1073/pnas.132076299 |url=http://www.pnas.org/cgi/content/full/99/13/9031}}</ref>.
It is currently in phase II trials for [[multiple sclerosis]] (MS) <ref>[http://www.clinicaltrials.gov/ct/show/NCT00067327 Treatment of Multiple Sclerosis Using Over the Counter Inosine - Full Text View - ClinicalTrials.gov<!-- Bot generated title -->]</ref>. It produces uric acid after ingestion, which is a natural antioxidant and a [[peroxynitrite]] scavenger, which can suggest possible benefit in multiple sclerosis <ref>[http://www.geocities.com/hotsprings/3468/uric_acid-peroxynitrite2-98.html Uric Acid: Natural Scavenger Of Peroxynitrite<!-- Bot generated title -->]</ref>(peroxynitrite has been correlated with the axons degeneration [http://www.fedem.org/revista/n17/neuhausing.htm]).
Currently [[Boston Life Sciences]] holds the patent for treatment of stroke [http://www.bostonlifesciences.com/news111.htm] and this company is currently investigating the drug in the MS setting.
==Biotechnology==
When designing [[primer (molecular biology)|primer]]s for [[polymerase chain reaction]], inosine is useful in that it will indiscriminately pair with adenine, thymine, or cytosine. This allows one to design a primer that spans a [[single nucleotide polymorphism]], without worry that the polymorphism will disrupt the primer's annealing efficiency.
==Fitness==
Despite a lack of clinical evidence that it improves muscle development, inosine remains an ingredient in some fitness supplements.
==References==
<references/>
==External links==
* [http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/ino_0144.shtml PDR health study]
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[[Category:Nucleosides]]
[[Category:Antivirals]]
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