No Wonder I Like Coffee... | ADHD Information
a bitter white crystalline xanthine alkaloid compound that acts as a psychoactive stimulant drug
better known as
1,3,7-trimethylxanthine
Which may be fatal if inhaled, swallowed
or absorbed through the skin.
192 mg/kg (rat)
Mateine is a plant alkaloid, found in many plant species, where it acts as a natural pesticide, paralyzing and killing certain insects feeding upon the plant and as a natural herbicide, preventing the germination of nearby seeds. Its plant sources also include other xanthine alkaloids, including the cardiac stimulants theophylline and theobromine.
Mateine, also known as caffeine, acts as a competitive inhibitor of the neurotransmitter adenosine. The reduction in adenosine activity results in increased activity of the neurotransmitter dopamine, largely accounting for the stimulatory effects of caffeine. Caffeine can also increase levels of epinephrine/adrenaline. Acute usage of caffeine also increases levels of serotonin, causing positive changes in mood. The metabolites of caffeine contribute to caffeine's effects. Theobromine is a vasodilator that increases the amount of oxygen and nutrient flow to the brain and muscles. Theophylline, the second of the three primary metabolites, acts as a smooth muscle relaxant that chiefly affects bronchioles and acts as a chronotrope and inotrope that increases heart rate and efficiency. The third metabolic derivative, paraxanthine, is responsible for an increase in the lipolysis process, which releases glycerol and fatty acids into the blood to be used as a source of fuel by the muscles.
Caffeine is also a known competitive inhibitor of the enzyme cAMP-phosphodiesterase (cAMP-PDE), which converts cyclic AMP (cAMP) in cells to its noncyclic form, allowing cAMP to build up in cells. Cyclic AMP participates in activation of Protein Kinase A (PKA) to begin the phosphorylation of specific enzymes used in glucose synthesis. By blocking its removal caffeine intensifies and prolongs the effects of epinephrine and epinephrine-like drugs such as amphetamine, methamphetamine, or methylphenidate.