AICA ribonucleotide

Mechanism of action

The nucleoside form of AICAR, acadesine, is an analog of adenosine that enters cardiac cells to inhibit adenosine kinase and adenosine deaminase. It enhances the rate of nucleotide re-synthesis increasing adenosine generation from adenosine monophosphate only during conditions of myocardial ischemia. In cardiac myocytes, acadesine is phosphorylated to AICAR to activate AMPK without changing the levels of the nucleotides. AICAR is able to enter the de novo synthesis pathway for adenosine synthesis to inhibit adenosine deaminase causing an increase in ATP levels and adenosine levels.

Use as a performance-enhancing drug

In 2009, the French Anti-Doping Agency, suspected that AICAR had been used in the 2009 Tour de France for its supposed performance enhancing properties. Although a detection method was reportedly given to the World Anti-Doping Agency, it was unknown if this method was implemented. As of January 2011, AICAR was officially a banned substance in the World Anti Doping Code, and the standard levels in elite athletes have been determined, to interpret test results.

References

References

1. Zarembo, Alan. (1 August 2008). "'Exercise pill' could take the work out of workouts". Los Angeles Times.
2. (2009). "5-Aminoimidazole-4-carboxamide-1-β-D-ribofuranoside increases myocardial glucose uptake during reperfusion and induces late pre-conditioning: Potential role of AMP-activated protein kinase". Basic & Clinical Pharmacology & Toxicology.
3. (2006). "Relationship between 5-aminoimidazole-4-carboxamide-ribotide and AMP-activated protein kinase activity in the perfused mouse heart". American Journal of Physiology. Heart and Circulatory Physiology.
4. (2003). "5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) stimulates myocardial glycogenolysis by allosteric mechanisms". American Journal of Physiology. Regulatory, Integrative and Comparative Physiology.
5. Cooke, Nicole. (11 March 2015). "Nicole Cooke: CIRC report is admirable but authorities must do more on drugs". The Guardian.
6. Niiler, Eric. (10 March 2015). "Doping spreading to amateur cyclists: Report". Seeker.
7. Simms, Daniel. (27 July 2009). "AFLD president suspects new drugs in peloton". Cyclingnews.
8. . (20 December 2010). ["Important changes made to the World Anti-Doping Code"](https://www.cyclingnews.com/news/important-changes-made-to-the-world-anti-doping-code/). *Cyclingnews*.
9. (2010). "Quantification of urinary AICAR concentrations as a matter of doping controls". Analytical and Bioanalytical Chemistry.
10. Cycling Independent Reform Commission. (February 2015). "Report to the President of the Union Cycliste Internationale".