title: Low, but not high, dose caffeine is a readily available probe for adenosine actions.
abstract: Caffeine is very widely used and knowledge of its mode of action can be used to gain an understanding of basal physiological regulation. This review makes the point that caffeine is - in low doses - an antagonist of adenosine acting at A1, A2Aand A2Breceptors. We use published and unpublished data to make the point that high dose effects of caffeine are not only qualitatively different but have a different underlying mechanism. Therefore one must be careful in only using epidemiological or experimental data where rather low doses of caffeine are used to draw conclusions about the physiology and pathophysiology of adenosine.
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77, Stockholm, Sweden. Electronic address: Bertil.Fredholm@ki.se.
authors.forename: Bertil B
authors.initials: BB
authors.lastname: Fredholm
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77, Stockholm, Sweden; Division of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jiangning
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77, Stockholm, Sweden; Division of Antitumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
authors.forename: Yingqing
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D002110:Caffeine / Q000378:metabolism* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D006801:Humans
chemical_list: D002110:Caffeine; D000241:Adenosine
keywords: Adenosine; Caffeine; Heart rate; Locomotion; Theophylline