Information about Xenobiotics
A xenobiotic is a chemical which is found in an organism but which is not normally produced or expected to be present in it. It can also cover substances which are present in much higher concentrations than are usual. Specifically, drugs such as antibiotics are xenobiotics in humans because the human body does not produce them itself nor would they be expected to be present as part of a normal diet. However, the term is also used in the context of pollutants such as dioxins and polychlorinated biphenyls and their effect on the biota. Natural compounds can also become xenobiotics if they are taken up by another organism (e.g., uptake of natural human hormones by fish found downstream of sewage treatment plant outfalls).
The body removes xenobiotics by xenobiotic metabolism. This consists of the deactivation and the secretion of xenobiotics, and happens mostly in the liver. Secretion routes are urine, feces, breath, and sweat. Hepatic enzymes are responsible for the metabolism of xenobiotics by first activating them (oxidation, reduction, hydrolysis and/or hydration of the xenobiotic), and then conjugating the active secondary metabolite with glucuronic or sulphuric acid, or glutathione, followed by excretion in bile or urine. An example of a group of enzymes involved in xenobiotic metabolism is hepatic microsomal cytochrome P450. These enzymes that metabolize xenobiotics are very important for the pharmaceutical industry, because they are responsible for the breakdown of medications.
The term xenobiotic is also used to refer to organs transplanted from one species to another. For example, some researchers hope that hearts and other organs could be transplanted from pigs to humans. Many people die every year whose lives could have been saved if a critical organ had been available for transplant. Kidneys are currently the most commonly transplanted organ. Xenobiotic organs would need to be developed in such a way that they would not be rejected by the immune system. With the development of vitrification transplantable organs could be stored in organ banks for long periods.
Xenobiotic substances are becoming an increasingly large problem in Sewage Treatment systems, since they are relatively new substances and are very difficult to categorize. Antibiotics, for example, were derived from plants originally, and so mimic naturally occurring substances. This, along with the natural monopoly nature of municipal Waste Water Treatment Plants makes it nearly impossible to remove this new pollutant load.
Some xenobiotics are resistant to degradation. For example, they may be synthetic organochlorides such as plastics and pesticides, or naturally occurring organic chemicals such as polyaromatic hydrocarbons (PAHs) and some fractions of crude oil and coal. However, it is believed that microorganisms are capable of degrading all the different complex and resistant xenobiotics found on the earth.
The body removes xenobiotics by xenobiotic metabolism. This consists of the deactivation and the secretion of xenobiotics, and happens mostly in the liver. Secretion routes are urine, feces, breath, and sweat. Hepatic enzymes are responsible for the metabolism of xenobiotics by first activating them (oxidation, reduction, hydrolysis and/or hydration of the xenobiotic), and then conjugating the active secondary metabolite with glucuronic or sulphuric acid, or glutathione, followed by excretion in bile or urine. An example of a group of enzymes involved in xenobiotic metabolism is hepatic microsomal cytochrome P450. These enzymes that metabolize xenobiotics are very important for the pharmaceutical industry, because they are responsible for the breakdown of medications.
The term xenobiotic is also used to refer to organs transplanted from one species to another. For example, some researchers hope that hearts and other organs could be transplanted from pigs to humans. Many people die every year whose lives could have been saved if a critical organ had been available for transplant. Kidneys are currently the most commonly transplanted organ. Xenobiotic organs would need to be developed in such a way that they would not be rejected by the immune system. With the development of vitrification transplantable organs could be stored in organ banks for long periods.
Xenobiotic substances are becoming an increasingly large problem in Sewage Treatment systems, since they are relatively new substances and are very difficult to categorize. Antibiotics, for example, were derived from plants originally, and so mimic naturally occurring substances. This, along with the natural monopoly nature of municipal Waste Water Treatment Plants makes it nearly impossible to remove this new pollutant load.
Some xenobiotics are resistant to degradation. For example, they may be synthetic organochlorides such as plastics and pesticides, or naturally occurring organic chemicals such as polyaromatic hydrocarbons (PAHs) and some fractions of crude oil and coal. However, it is believed that microorganisms are capable of degrading all the different complex and resistant xenobiotics found on the earth.
See also
External links
- Re-engineering the toilet for sustainable wastewater management
- International Society for the Study of Xenobiotics
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Plantae Chromalveolata Heterokontophyta Haptophyta Cryptophyta Alveolata
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Substance may refer to:
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- Substance theory, in philosophy, that element of an object without which it would not exist, or what exists only by itself (causa sui)
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In chemistry, concentration is the measure of how much of a given substance there is mixed with another substance. This can apply to any sort of chemical mixture, but most frequently the concept is limited to homogeneous solutions, where it refers to the amount of
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A medication, medicine or drug is any substance or combination of substances administered to human beings or animals to treat or prevent disease; alternatively to assist in medical diagnosis.
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antibiotic is a chemotherapeutic agent that inhibits or abolishes the growth of micro-organisms, such as bacteria, fungi, or protozoans. The term originally referred to any agent with biological activity against living organisms; however, "antibiotic" now is used to refer to
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Pollution is the introduction of pollutants (whether chemical substances, or energy such as noise, heat, or light) into the environment to such a point that its effects become harmful to human health, other living organisms, or the environment.
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Dioxin in its original usage denoted the organochemical heterocyclic compound with the general chemical formula C4H4O2 in which two CH groups of a benzene ring were replaced (endocyclic substitution) by oxygen atoms, of which two isomers were
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Polychlorinated biphenyls (PCBs) are a class of organic compounds with 1 to 10 chlorine atoms attached to biphenyl and a general chemical formula of C12H10-xClx.
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Biota may refer to:
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- Biota (ecology)— the plant and animal life of a region
- Biota (taxonomy)— a superdomain in taxonomy
- Biota, Zaragoza— a municipality in Zaragoza province, Spain
- Biota Holdings — an Australian biotech company
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Cytochrome P450 (abbreviated CYP, P450, infrequently CYP450) is a very large and diverse superfamily of hemoproteins found in bacteria, archaea and eukaryotes.[1] They are so named because of their properties i.e.
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organ (Latin: organum, "instrument, tool") is a group of tissues that perform a specific function or group of functions. Usually there is a main tissue and sporadic tissues. The main tissue is the one that is unique for the specific organ.
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organ transplant is the moving of a whole or partial organ from one body to another (or from a donor site on the patient's own body), for the purpose of replacing the recipient's damaged or failing organ with a working one from the donor site.
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species is one of the basic units of biological classification. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
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heart is a muscular organ responsible for pumping blood through the blood vessels by repeated, rhythmic contractions, or a similar structure in the annelids, mollusks, and arthropods.
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Sus
Linnaeus, 1758
Species
Sus barbatus
Sus bucculentus†
Sus cebifrons
Sus celebensis
Sus domestica
Sus falconeri†
Sus heureni
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Linnaeus, 1758
Species
Sus barbatus
Sus bucculentus†
Sus cebifrons
Sus celebensis
Sus domestica
Sus falconeri†
Sus heureni
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The kidneys are organs that filter wastes (such as urea) from the blood and excrete them, along with water, as urine. The medical field that studies the kidneys and diseases of the kidney is called nephrology[1].
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Immunity is a medical term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components.
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Vitrification is a process of converting a material into a glass-like amorphous solid which is free from any crystalline structure, either by the quick removal or addition of heat, or by mixing with an additive.
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Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater, both runoff and domestic. It includes physical, chemical and biological processes to remove physical, chemical and biological contaminants.
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antibiotic is a chemotherapeutic agent that inhibits or abolishes the growth of micro-organisms, such as bacteria, fungi, or protozoans. The term originally referred to any agent with biological activity against living organisms; however, "antibiotic" now is used to refer to
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United States
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- Sherman Antitrust Act
- Clayton Antitrust Act
- Robinson-Patman Act
- Federal Trade Commission Act
- Essential facilities doctrine
- Noerr-Pennington doctrine
- Rule of reason
- European Community
competition law
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An organochloride, organochlorine, or chlorocarbon, is an organic compound containing at least one covalently bonded chlorine atom. Their wide structural variety and divergent chemical properties lead to a broad range of uses.
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Xenotransplantation (xeno- from the Greek meaning "foreign") is the transplantation of living cells, tissues or organs from one species to another such as from pigs to humans (see Medical grafting).
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An artificial organ is a man-made organ that is implanted into, or integrated onto, a human to replace a natural organ, for the purpose of restoring a specific function or a group of related functions so the patient may return to as normal a life as possible.
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Organ donation is the removal of the tissues of the human body from a person who has recently died, or from a living donor, for the purpose of transplanting or grafting them into other persons.
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In medicine, grafting is a surgical procedure to transplant tissue without a blood supply. The implanted tissue must obtain a blood supply from the new vascular bed or otherwise die.
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Drug metabolism is the metabolism of drugs, their biochemical modification or degradation, usually through specialized enzymatic systems. Drug metabolism often converts lipophilic chemical compounds into more readily excreted polar products.
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