Alkylxanthines as research tools.
(1) The methylxanthine caffeine has many pharmacological effects, most of which can be linked to blockade of adenosine receptors, inhibition of phosphodiesterases, and augmentation of calcium-dependent release of calcium from intracellular stores. (2) A variety of xanthines have been developed as potent and/or selective antagonists for adenosine receptors. (3) Several xanthines have been developed that are more potent and more selective inhibitors of cyclic nucleotide phosphodiesterase than caffeine or theophylline. (4) Caffeine remains the xanthine of choice for activation of intracellular calcium-sensitive calcium release channels although millimolar concentrations are required, which can have effects on other aspects of calcium regulation.
Daly
J W
JW
Section on Pharmacodynamics, Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
D000818:Animals; D002118:Calcium / Q000502:physiology; D006801:Humans; D007473:Ion Channels / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology; D018047:Receptors, Purinergic P1 / Q000187:drug effects; D014970:Xanthines / Q000494:pharmacology
D007473:Ion Channels; D010726:Phosphodiesterase Inhibitors; D011963:Receptors, GABA-A; D018047:Receptors, Purinergic P1; D014970:Xanthines; D002118:Calcium