File Name: drug metabolism phase 1 and 2 .zip
Drug metabolizing enzymes DMEs play central roles in the metabolism, elimination and detoxification of xenobiotics and drugs introduced into the human body. Recently, many important advances have been made in the mechanisms that regulate the expression of these drug metabolism genes. Various nuclear receptors including the aryl hydrocarbon receptor AhR , orphan nuclear receptors, and nuclear factor-erythoroid 2 prelated factor 2 Nrf2 have been shown to be the key mediators of drug-induced changes in phase I, phase II metabolizing enzymes as well as phase III transporters involved in efflux mechanisms.
Topics on Drug Metabolism. All organisms are constantly and unavoidably exposed to xenobiotics including both man—made and natural chemicals such as drugs, plant alkaloids, microorganism toxins, pollutants, pesticides, and other industrial chemicals. Formally, biotransformation of xenobiotics as well as endogenous compounds is subdivided into phase I and phase II reactions. On the other hand, these conjugations also play an essential role in the toxicity of many chemicals due to the metabolic formation of toxic metabolites such as reactive electrophiles. Gene polymorphism of biotransformation enzymes may often play a role in various pathophysiological processes. Conjugation reactions usually involve metabolite activation by a high—energy intermediate and have been classified into two general types: type I e. In this chapter, we will concentrate on the most important conjugation reactions, namely glucuronide conjugation, sulfoconjugation, acetylation, amino acid conjugation, glutathione conjugation and methylation.
Drug metabolism is the metabolic breakdown of drugs by living organisms , usually through specialized enzymatic systems. More generally, xenobiotic metabolism from the Greek xenos "stranger" and biotic "related to living beings" is the set of metabolic pathways that modify the chemical structure of xenobiotics , which are compounds foreign to an organism's normal biochemistry, such as any drug or poison. These pathways are a form of biotransformation present in all major groups of organisms and are considered to be of ancient origin. These reactions often act to detoxify poisonous compounds although in some cases the intermediates in xenobiotic metabolism can themselves cause toxic effects. The study of drug metabolism is called pharmacokinetics. The metabolism of pharmaceutical drugs is an important aspect of pharmacology and medicine. For example, the rate of metabolism determines the duration and intensity of a drug's pharmacologic action.
If your institution subscribes to this resource, and you don't have a MyAccess Profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus. Please consult the latest official manual style if you have any questions regarding the format accuracy. All organisms are exposed to foreign chemical compounds xenobiotics in the air, water, and food. To ensure elimination of pharmacologically active xenobiotics as well as to terminate the action of many endogenous substances, evolution has provided metabolic pathways that alter their activity and their susceptibility to excretion. Many cells that act as portals for entry of external molecules into the body eg, pulmonary epithelium, intestinal epithelium contain transporter molecules MDR family [P-glycoproteins], MRP family, others that expel unwanted molecules immediately after absorption.
The liver is the principal site of drug metabolism for review, see [ 1 ]. Although metabolism typically inactivates drugs, some drug metabolites are pharmacologically active—sometimes even more so than the parent compound. An inactive or weakly active substance that has an active metabolite is called a prodrug, especially if designed to deliver the active moiety more effectively. Drugs can be metabolized by oxidation, reduction, hydrolysis, hydration, conjugation, condensation, or isomerization; whatever the process, the goal is to make the drug easier to excrete. The enzymes involved in metabolism are present in many tissues but generally are more concentrated in the liver.
Introduction to Drug Metabolism pp Cite as. The routes by which drugs may be metabolised or biotransformed are many and varied and include the chemical reactions of oxidation, reduction, hydrolysis, hydration, conjugation and condensation. It is important that these pathways are studied as the route of metabolism of a drug can determine whether it shows any pharmacological or toxicological activity. Drug metabolism is normally divided into two phases, phase I or functionalisation reactions and phase II or conjugative reactions.
DOI : Genetic variation in the receptors and other intracellular targets that mediate the pharmacodynamic effects of drugs can affect therapeutic outcomes. However, at present greater knowledge is available concerning the extent of gene variation in drug metabolizing enzymes that determine drug pharmacokinetics and, in turn, drug efficacy and toxicity.
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Сьюзан оставила это замечание без ответа. - У правительств должно быть право собирать информацию, в которой может содержаться угроза общественной безопасности. - Господи Иисусе! - шумно вздохнул Хейл.
У тебя скверный вкус на ювелирные побрякушки. - Ты уверен, что его никто не купил. - Да вы все спятили. Это за четыреста-то баксов. Я сказал ей, что даю пятьдесят, но она хотела .
Само ее существование противоречило основным правилам криптографии. Она посмотрела на шефа. - Вы уничтожите этот алгоритм сразу же после того, как мы с ним познакомимся.
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