Adenosine A1 receptors determine effects of caffeine on total fluid intake but not caffeine appetite

Eur J Pharmacol. 2007 Jan 26;555(2-3):174-7. doi: 10.1016/j.ejphar.2006.10.039. Epub 2006 Oct 25.


Adenosine A1 receptor wild-type (+/+) and knockout (-/-) mice were used to elucidate the role of adenosine A1 receptors in caffeine self-administration in a two-bottle choice test and in the effect of caffeine on total fluid intake and plasma renin concentration. With access to water only, adenosine A1 receptor -/- mice showed greater basal fluid intake and greater plasma renin concentration than +/+ mice. Free access to both water and a caffeinated solution (30 mg/100 ml) for 14 days increased total fluid intake only in adenosine A1 receptor +/+ mice (by 23+/-3%), and both total fluid intake and plasma renin concentration were no longer different between genotypes. Mean intake of water and caffeinated solution was not different between adenosine A1 receptor +/+ and -/- mice. These data reveal that adenosine A1 receptors do not contribute to caffeine consumption, but determine the effects of caffeine on fluid intake and plasma renin concentration.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Appetite / drug effects*
  • Appetite / physiology
  • Caffeine / administration & dosage*
  • Central Nervous System Stimulants / administration & dosage
  • Drinking Behavior / drug effects*
  • Drinking Behavior / physiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Receptor, Adenosine A1 / genetics
  • Receptor, Adenosine A1 / physiology*
  • Renin / blood


  • Central Nervous System Stimulants
  • Receptor, Adenosine A1
  • Caffeine
  • Renin