Inverse agonist 1200465 225033446 2008-07-11T15:47:28Z 69.140.152.55 wikilink to section [[Image:inverseagonist.gif|thumb|300 px|Diagram showing effect of inverse agonist]] In [[pharmacology]], an '''inverse agonist''' is an agent which binds to the same [[receptor (biochemistry)|receptor]] binding-site as an [[agonist]] for that receptor and reverses [[Receptor (biochemistry)#Constitutive activity|constitutive activity]] of receptors.<ref>{{cite journal |author=Kenakin T |title=Principles: receptor theory in pharmacology |journal=Trends Pharmacol. Sci. |volume=25 |issue=4 |pages=186–92 |year=2004 |pmid=15063082 |doi=10.1016/j.tips.2004.02.012 |url=}}</ref> Inverse agonists exert the opposite pharmacological effect of a receptor agonist. Inverse agonists are effective against certain types of receptors (e.g. certain [[histamine receptor]]s and [[GABA receptors]]<ref>{{cite journal |author=Mehta AK, Ticku MK |title=Ethanol potentiation of GABAergic transmission in cultured spinal cord neurons involves gamma-aminobutyric acidA-gated chloride channels |journal=J. Pharmacol. Exp. Ther. |volume=246 |issue=2 |pages=558–64 |year=1988 |pmid=2457076 |doi= |url=http://jpet.aspetjournals.org/cgi/pmidlookup?view=long&pmid=2457076}}</ref>) which have intrinsic activity without the action of a ligand upon them (also referred to as 'constitutive activity'.) Receptor [[agonists]], [[Receptor antagonist|antagonists]] and inverse agonists bind to the same receptor types. The pharmacological effect of an inverse agonist is measured as the negative value of the agonist primarily due to the historical findings of the already known agonist. Therefore, if the agonist has a positive value and the inverse agonist has a negative value, the antagonist for the receptor takes both the agonist and inverse agonist back to a neutral state. One particular example is [[R015-4513|Ro15-4513]] which is the inverse agonist of the [[benzodiazepine]] class of drugs (such as [[alprazolam]] and [[diazepam]]). Ro15-4513 and the benzodiazepines both utilize the same GABA binding site on neurons, yet Ro15-4513 has the opposite effect, producing anxiety rather than the sedative effect of the benzodiazepines.<ref>{{cite journal |author=Sieghart W |title=Pharmacology of benzodiazepine receptors: an update |journal=J Psychiatry Neurosci |volume=19 |issue=1 |pages=24–9 |year=1994 |pmid=8148363 |doi= |url=}}</ref> ==References== <references/> ==See also== * [[Agonist]] * [[Receptor antagonist]] ==External links== *[http://medicine.creighton.edu/pharmacology/inverse.htm Inverse Agonists for Medical Students] by William B. Jeffries, Ph.D., Creighton University Department of Pharmacology [[Category:Pharmacology]] [[de:Inverser Agonist]] [[fr:Agoniste inverse]] [[fi:Käänteisagonisti]] [[zh:反相激动剂]]