Enzyme induction and inhibition - Revision history

wikademia>Eme at 06:49, 22 November 2009

2009-11-22T06:49:07Z

← Older revision		Revision as of 06:49, 22 November 2009
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	~~{{dablink\|This article is about [[enzyme]] regulation at the [[gene expression]] level. For the inhibition of enzymes at the enzyme level, see '''[[enzyme inhibitor]]'''.}}~~
	'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].		'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].
	{{?}}		{{?}}

wikademia>Wikademia at 05:17, 29 June 2009

2009-06-29T05:17:59Z

← Older revision		Revision as of 05:17, 29 June 2009
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	[[Category:Pharmacokinetics]]		[[Category:Pharmacokinetics]]
	[[Category:Gene expression]]		[[Category:Gene expression]]

	~~[[de:Enzyminduktion]]~~
	~~[[nl:enzym inductie]]~~

wikademia>Wikademia at 17:57, 8 June 2009

2009-06-08T17:57:58Z

← Older revision		Revision as of 17:57, 8 June 2009
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	~~<!-- Please do not remove or change this AfD message until the issue is settled -->~~
	~~{{AfDM\|page=Enzyme induction and inhibition\|logdate=2009 May 17\|substed=yes }}~~
	~~<!-- For administrator use only: {{oldafdfull\|page=Enzyme induction and inhibition\|date=17 May 2009\|result='''keep'''}} -->~~
	~~<!-- End of AfD message, feel free to edit beyond this point -->~~
	{{dablink\|This article is about [[enzyme]] regulation at the [[gene expression]] level. For the inhibition of enzymes at the enzyme level, see '''[[enzyme inhibitor]]'''.}}		{{dablink\|This article is about [[enzyme]] regulation at the [[gene expression]] level. For the inhibition of enzymes at the enzyme level, see '''[[enzyme inhibitor]]'''.}}
	'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].		'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].
			{{?}}
	'''Enzyme inhibition''' can refer to		'''Enzyme inhibition''' can refer to
	* the inhibition of the expression of the enzyme by another molecule		* the inhibition of the expression of the enzyme by another molecule

wikademia>Wikademia: 34 revisions

2009-05-25T04:45:22Z

34 revisions

← Older revision	Revision as of 04:45, 25 May 2009
(No difference)

wikademia>Cunard: re-opened the AfD

2009-05-24T18:07:45Z

re-opened the AfD

← Older revision		Revision as of 18:07, 24 May 2009
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			<!-- Please do not remove or change this AfD message until the issue is settled -->
			{{AfDM\|page=Enzyme induction and inhibition\|logdate=2009 May 17\|substed=yes }}
			<!-- For administrator use only: {{oldafdfull\|page=Enzyme induction and inhibition\|date=17 May 2009\|result='''keep'''}} -->
			<!-- End of AfD message, feel free to edit beyond this point -->
	{{dablink\|This article is about [[enzyme]] regulation at the [[gene expression]] level. For the inhibition of enzymes at the enzyme level, see '''[[enzyme inhibitor]]'''.}}		{{dablink\|This article is about [[enzyme]] regulation at the [[gene expression]] level. For the inhibition of enzymes at the enzyme level, see '''[[enzyme inhibitor]]'''.}}
	'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].		'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].

wikademia>Stevenfruitsmaak: restore with dablink

2009-05-24T10:10:19Z

restore with dablink

← Older revision		Revision as of 10:10, 24 May 2009
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	{{~~rfd~~}}		{{dablink\|This article is about [[enzyme]] regulation at the [[gene expression]] level. For the inhibition of enzymes at the enzyme level, see '''[[enzyme inhibitor]]'''.}}
	#~~REDIRECT~~ [[enzyme ~~inhibitor~~]]		'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an [[enzyme]].

			'''Enzyme inhibition''' can refer to
			* the inhibition of the expression of the enzyme by another molecule
			* [[Enzyme inhibitor\|interference at the enzyme-level]], basically with how the enzyme works. This can be [[competitive inhibition]], [[uncompetitive inhibition]], [[non-competitive inhibition]] or partially competitive inhibition.

			If the molecule induces enzymes that are responsible for its own [[metabolism]], this is called '''auto-induction''' (or '''auto-inhibition''' if there is inhibition). These processes are particular forms of [[Regulation of gene expression\|gene expression regulation]].

			These terms are of particular interest to [[pharmacology]], and more specifically to [[drug metabolism]] and [[drug interaction]]s. They also apply to [[molecular biology]].

			==History==
			In the late 1950s and early 1960s, the French molecular biologists [[François Jacob]] and [[Jacques Monod]] became the first to explain enzyme induction, in the context of the [[lac operon]] of [[Escherichia coli]]. In the absence of lactose, the constitutively expressed [[lac repressor]] protein binds to the operator region of the DNA and prevents the transcription of the operon genes. When present, lactose binds to the lac repressor, causing it to separate from the DNA and thereby enabling transcription to occur. Monod and Jacob generated this theory following 15 years of work by them and others (including [[Joshua Lederberg]]), partially as an explanation for Monod's observation of [[diauxie]]. Previously, Monod had hypothesized that enzymes could physically adapt themselves to new substrates; a series of experiments by him, Jacob, and [[Arthur Pardee]] eventually demonstrated this to be incorrect and led them to the modern theory, for which he and Jacob shared the [[1965]] [[Nobel_Prize_in_Physiology_or_Medicine\|Nobel Prize in Physiology or Medicine]] (together with [[André Lwoff]]).<ref>{{cite web\|last = Mulligan\|first = Martin\|title = Induction\|url=http://www.mun.ca/biochem/courses/4103/topics/induction.html\|accessdate = 2007-01-01}}</ref>

			==Cytochrome P450==
			{{Main\|Cytochrome P450#Drug metabolism}}
			One class of key enzymes for drug metabolism belong to the family of [[cytochrome P450 oxidase]]s, like [[CYP3A4]], [[CYP2D6]], [[CYP1A2]], ''etc''. They reside in the [[endoplasmatic reticulum]] (ER), and prolonged usage of substances inducing enzymes here may cause proliferation of the ER. They are responsible for [[Drug metabolism#Phase I vs. Phase II\|phase I reactions]].

			Enzyme induction and inhibition are important processes to take in account when using drugs of vital importance to the patient, drugs with important [[side effects]] and drugs with small [[therapeutic window]]s, but any drug may be subject to an altered plasma concentration due to altered [[drug metabolism]].

			A classical example includes [[Anticonvulsant\|anti-epileptic drugs]]. [[Phenytoin]], for example, induces [[CYP1A2]], [[CYP2C9]], [[CYP2C19]] and [[CYP3A4]]. Substrates for the latter may be drugs with critical dosage, like [[amiodarone]] or [[carbamazepine]], whose [[blood plasma]] [[concentration]] may decrease because of enzyme induction.

			Not only drugs may alter drug metabolism. [[Tobacco smoking]] induces [[CYP1A2]] (example substrates are [[clozapine]]/[[olanzapine]]), [[Saint-John's wort]] (a common [[herbal remedy]]) induces [[CYP3A4]], which is inhibited by [[grapefruit juice]]. There are known examples of situations where this may produce clinical effects.

			==References==
			<references/>

			==External links==
			* {{MeshName\|Enzymologic+Gene+Expression+Regulation}}

			[[Category:Pharmacokinetics]]
			[[Category:Gene expression]]

			[[de:Enzyminduktion]]
			[[nl:enzym inductie]]

wikademia>Cunard: Nominated for RFD: see Wikipedia:Redirects for discussion/Log/2009 May 24#Enzyme induction and inhibition

2009-05-24T06:56:03Z

Nominated for RFD: see Wikipedia:Redirects for discussion/Log/2009 May 24#Enzyme induction and inhibition

← Older revision		Revision as of 06:56, 24 May 2009
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			{{rfd}}
	#REDIRECT [[enzyme inhibitor]]		#REDIRECT [[enzyme inhibitor]]

wikademia>Cunard: Wikipedia:Articles for deletion/Enzyme induction and inhibition closed as procedural keep and list at Wikipedia:Redirects for discussion/Log/2009 May 24#Enzyme induction and inhibition

2009-05-24T06:55:06Z

Wikipedia:Articles for deletion/Enzyme induction and inhibition closed as procedural keep and list at Wikipedia:Redirects for discussion/Log/2009 May 24#Enzyme induction and inhibition

← Older revision		Revision as of 06:55, 24 May 2009
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	~~<!-- Please do not remove or change this AfD message until the issue is settled -->~~
	~~{{AfDM\|page=Enzyme induction and inhibition\|logdate=2009 May 17\|substed=yes }}~~
	~~<!-- For administrator use only: {{oldafdfull\|page=Enzyme induction and inhibition\|date=17 May 2009\|result='''keep'''}} -->~~
	~~<!-- End of AfD message, feel free to edit beyond this point -->~~
	#REDIRECT [[enzyme inhibitor]]		#REDIRECT [[enzyme inhibitor]]

wikademia>Captain-n00dle: Nominated for deletion; see Wikipedia:Articles for deletion/Enzyme induction and inhibition. (TW)

2009-05-17T14:15:08Z

Nominated for deletion; see Wikipedia:Articles for deletion/Enzyme induction and inhibition. (TW)

← Older revision		Revision as of 14:15, 17 May 2009
Line 1:		Line 1:
			<!-- Please do not remove or change this AfD message until the issue is settled -->
			{{AfDM\|page=Enzyme induction and inhibition\|logdate=2009 May 17\|substed=yes }}
			<!-- For administrator use only: {{oldafdfull\|page=Enzyme induction and inhibition\|date=17 May 2009\|result='''keep'''}} -->
			<!-- End of AfD message, feel free to edit beyond this point -->
	#REDIRECT [[enzyme inhibitor]]		#REDIRECT [[enzyme inhibitor]]

wikademia>ClockworkSoul: Ham-fisted redirect to enzyme inhibitor.

2008-02-29T08:50:12Z

Ham-fisted redirect to enzyme inhibitor.

← Older revision		Revision as of 08:50, 29 February 2008
Line 1:		Line 1:
	~~'''Enzyme induction''' is a process in which a [[molecule]] (''e.g.'' a drug) [[Induction (biology)\|induces]] (''i.e.'' initiates or enhances) the [[gene expression\|expression]] of an~~ [[enzyme~~]].~~		#REDIRECT [[enzyme inhibitor]]

	~~'''Enzyme inhibition''' can refer to~~
	* the inhibition of the expression of the enzyme by another molecule
	* [[Enzyme inhibitor\|interference at the enzyme-level]], basically with how the enzyme works. This can be [[competitive inhibition]], [[uncompetitive inhibition]], [[non-competitive inhibition]] or partially competitive inhibition.

	If the molecule induces enzymes that are responsible for its own [[metabolism]], this is called '''auto-induction''' (or '''auto-inhibition''' if there is inhibition). These processes are particular forms of [[Regulation of gene expression\|gene expression regulation]].

	~~These terms are of particular interest to [[pharmacology]], and more specifically to [[drug metabolism]] and [[drug interaction]]s. They also apply to [[molecular biology]].~~

	In the late 1950s and early 1960s, the French molecular biologists [[François Jacob]] and [[Jacques Monod]] became the first to explain enzyme induction, in the context of the [[lac operon]] of [[Escherichia coli]]. In the absence of lactose, the constitutively expressed [[lac repressor]] protein binds to the operator region of the DNA and prevents the transcription of the operon genes. When present, lactose binds to the lac repressor, causing it to separate from the DNA and thereby enabling transcription to occur. Monod and Jacob generated this theory following 15 years of work by them and others (including [[Joshua Lederberg]]), partially as an explanation for Monod's observation of [[diauxie]]. Previously, Monod had hypothesized that enzymes could physically adapt themselves to new substrates; a series of experiments by him, Jacob, and [[Arthur Pardee]] eventually demonstrated this to be incorrect and led them to the modern theory, for which he and Jacob shared the [[1965]] [[Nobel_Prize_in_Physiology_or_Medicine\|Nobel Prize in Physiology or Medicine]] (together with [[André Lwoff]]).<ref>{{cite web\|last = Mulligan\|first = Martin\|title = Induction\|url=http://www.mun.ca/biochem/courses/4103/topics/induction.html\|accessdate = 2007-01-01}}</ref>

	~~==Cytochrome P450==~~
	~~{{Main\|Cytochrome P450#Drug metabolism}}~~
	One class of key enzymes for drug metabolism belong to the family of [[cytochrome P450 oxidase]]s, like [[CYP3A4]], [[CYP2D6]], [[CYP1A2]], ''etc''. They reside in the [[endoplasmatic reticulum]] (ER), and prolonged usage of substances inducing enzymes here may cause proliferation of the ER. They are responsible for [[Drug metabolism#Phase I vs. Phase II\|phase I reactions]].

	Enzyme induction and inhibition are important processes to take in account when using drugs of vital importance to the patient, drugs with important [[side effects]] and drugs with small [[therapeutic window]]s, but any drug may be subject to an altered plasma concentration due to altered [[drug metabolism]].

	A classical example includes [[Anticonvulsant\|anti-epileptic drugs]]. [[Phenytoin]], for example, induces [[CYP1A2]], [[CYP2C9]], [[CYP2C19]] and [[CYP3A4]]. Substrates for the latter may be drugs with critical dosage, like [[amiodarone]] or [[carbamazepine]], whose [[blood plasma]] [[concentration]] may decrease because of enzyme induction.

	Not only drugs may alter drug metabolism. [[Tobacco smoking]] induces [[CYP1A2]] (example substrates are [[clozapine]]/[[olanzapine]]), [[Saint-John's wort]] (a common [[herbal remedy]]) induces [[CYP3A4]], which is inhibited by [[grapefruit juice]]. There are known examples of situations where this may produce clinical effects.

	~~==References==~~
	~~<references/>~~

	~~==External links==~~
	* {{MeshName\|Enzymologic+Gene+Expression+Regulation}}

	~~[[Category:Pharmacokinetics]]~~
	~~[[Category:Gene expression]]~~

	~~[[de:Enzyminduktion]]~~
	~~[[nl:enzym inductie~~]]