Pharmacology is a part of medicine studing effects of drugs. Drugs are active principles. How does it works? Most of drugs bind to proteins and their pharmacological activity is due to this union. What are the fictions of proteins regulated by drugs?

1.- Proteins that are enzymes. The encymes produce chemical reactions (example digestive enzymes cut food nutrients in parts).
Some enzymes produce toxic compounds, for example ciclootygenase type 2 ( = COX-2) produce prostraglandin E2, that is a proinflamatory substances. Acetyl salicylic acid clocks COX-2 and there is not inflamation.

2.- Pictein as receptors m the membrane, some of them are channels and others stimuletes other proteins (example protein G). We black the receptor of serotonin and not using drug fluoxetine, that increases the level of serotonin and reduce the depression.