Regulation of stimulation

Many alkaloids are generally known to have stimulating properties, such as caffeine, cathine, theobromine and theophylline. These alkaloids are considered in many different medical applications. 

Caffeine is a known inhibitor of phosphodiesterase. Caffeine has an effect on calcium-mediated signalling namely it causes an increase of cAMP activity. Caffeine also has a competitive effect on the central adenosine receptor and is thought to increase analgesic activity. It is also known to be somewhat effective 

Catiline is a known inhibitor of monoamine oxidase and a central stimulant as an indirect sympathomimetic. It is found in anorectic products. 

Theobromine is an alkaloid used in medicine much like caffeine, due to the similar properties of these two alkaloids. Theobromine is not as potent as caffeine. Theobromine stimulates the CNS and increases blood flow. 

Theophylline also has similar possible clinical applications. This alkaloid has a high level of purines, and because of this it can act as a relaxant. It has also been used in the prevention of bronchospasms. 

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