Possible therapeutic benefits of adenosine-potentiating drugs in reducing age-related degenerative disease in dogs and cats.
Adenosine is a ubiquitous, biologically important molecule that is a precursor of other biologically active molecules. It also is a component of some co-factors and has distinct physiological actions in its own right. Levels are maintained by synthesis from dietary precursors and re-cycling. The daily turnover of adenosine is very high. Adenosine can act either as a hormone by binding to adenosine receptors, four adenosine receptor subtypes have been identified, and as an intracellular modulator, after transport into the cell by membrane transporter proteins. One of the principal intracellular actions of adenosine is inhibition of the enzyme phosphodiesterase. Extracellular adenosine also has specific neuromodulatory actions on dopamine and glutamate. Selective and nonselective agonists and antagonists of adenosine are available. The tasks of developing, evaluating and exploiting the therapeutic potential of these compounds is still in its infancy. Adenosine has actions in the central nervous system (CNS), heart and vascular system, skeletal muscle and the immune system and the presence of receptors suggests potential actions in the gonads and other organs. Adenosine agonists improve tissue perfusion through actions on vascular smooth muscle and erythrocyte fluidity and they can be used to improve the quality of life in aged dogs. This article reviews the therapeutic potential of adenosine-potentiating drugs in the treatment of age-related conditions in companion animals, some of which may be exacerbated by castration or spaying at an early age.
Scaramuzzi
R J
RJ
Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK. rscara@rvc.ac.uk
Baker
D J
DJ
D000241:Adenosine / Q000031:analogs & derivatives* / Q000502:physiology*; D000375:Aging; D000818:Animals; D002371:Cat Diseases / Q000188:drug therapy*; D002415:Cats; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D019636:Neurodegenerative Diseases / Q000188:drug therapy / Q000662:veterinary*; D018696:Neuroprotective Agents / Q000627:therapeutic use*
D018696:Neuroprotective Agents; D000241:Adenosine