Exogenous compounds (xenobiotics) must be metabolized before they can be excreted. The biochemical transformation of xenobiotics, such as alcohol, nicotine and drugs is a prime activity of the liver. In addition to the liver, biotransformation processes occur in plasma, in the lungs, in the gastrointestinal tract and in the skin. Because of their poor solubility in water, lipophilic substances are reabsorbed in the renal tubules and are excreted only slowly by the kidneys. The elimination velocity of lipophilic compounds depends on their transformation to water soluble substances. Hepatic biotransformation increases the polarity of xenobiotics, thereby increasing their solubility in water and enhancing their biliary and renal excretion,.
KeywordsEnzyme Inducer Conjugation Reaction CYP450 Isoenzyme Mercapturic Acid Mixed Function Oxidase
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