http://linked.open...gbank/description
| - A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes smooth muscle, stimulates cardiac muscle, stimulates diuresis, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide phosphodiesterases, antagonism of adenosine receptors, and modulation of intracellular calcium handling. [PubChem] (en)
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http://linked.open...generalReferences
| - # Nathanson JA: Caffeine and related methylxanthines: possible naturally occurring pesticides. Science. 1984 Oct 12;226(4671):184-7. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/6207592 # Haskell CF, Kennedy DO, Wesnes KA, Milne AL, Scholey AB: A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guarana in humans. J Psychopharmacol. 2007 Jan;21(1):65-70. Epub 2006 Mar 13. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/16533867 # Smit HJ, Gaffan EA, Rogers PJ: Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Psychopharmacology (Berl). 2004 Nov;176(3-4):412-9. Epub 2004 May 5. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/15549276 # Benjamin LT Jr, Rogers AM, Rosenbaum A: Coca-Cola, caffeine, and mental deficiency: Harry Hollingworth and the Chattanooga trial of 1911. J Hist Behav Sci. 1991 Jan;27(1):42-55. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/2010614 # Nehlig A, Daval JL, Debry G: Caffeine and the central nervous system: mechanisms of action, biochemical, metabolic and psychostimulant effects. Brain Res Brain Res Rev. 1992 May-Aug;17(2):139-70. "Pubmed":http://www.ncbi.nlm.nih.gov/pubmed/1356551 (en)
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http://linked.open...mechanismOfAction
| - Caffeine stimulates medullary, vagal, vasomotor, and respiratory centers, promoting bradycardia, vasoconstriction, and increased respiratory rate. This action was previously believed to be due primarily to increased intracellular cyclic 3′,5′-adenosine monophosphate (cyclic AMP) following inhibition of phosphodiesterase, the enzyme that degrades cyclic AMP. It is now thought that xanthines such as caffeine act as antagonists at adenosine-receptors within the plasma membrane of virtually every cell. As adenosine acts as an autocoid, inhibiting the release of neurotransmitters from presynaptic sites but augmenting the actions of norepinephrine or angiotensin, antagonism of adenosine receptors promotes neurotransmitter release. This explains the stimulatory effects of caffeine. Blockade of the adenosine A1 receptor in the heart leads to the accelerated, pronounced "pounding" of the heart upon caffeine intake. (en)
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