{{Short description|Pharmacokinetics parameter}} The '''free fraction''' is a parameter in pharmacokinetics and receptor-ligand kinetics. One speaks of two different free fractions: * ''Plasma free fraction'', previously referred to as ƒ<sub>1</sub>,<ref name="GunnR2002Positron">{{Cite journal | title = Positron Emission Tomography Compartmental Models: A Basis Pursuit Strategy for Kinetic Modeling | journal = J. Cereb. Blood Metab. | volume = 22 | issue = 4 | pages = 1425–1439 | year = 2002 | doi = 10.1097/00004647-200212000-00003 | pmid = 12468888 | author1 = Roger N. Gunn | author2 = Steve R. Gunn | author3 = Federico E. Turkheimer | author4 = Vincent J. Cunningham | authorlink1 = Roger N. Gunn | authorlink4 = Vincent J. Cunningham }}[http://www.nature.com/jcbfm/journal/v22/n12/fig_tab/9591337t4.html Table]</ref> is now referred to as ƒ<sub>P</sub> according to consensus nomenclature.<ref>{{Cite journal | title = Consensus nomenclature for in vivo imaging of reversibly binding radioligands | journal = J Cereb Blood Flow Metab | year = 2007 | volume = 27 | issue = 9 | pages = 1533–1539 | doi = 10.1038/sj.jcbfm.9600493 | pmid = 17519979 | last2 = Cunningham | first2 = VJ | last3 = Delforge | first3 = J | last4 = Fujita | first4 = M | last5 = Gjedde | first5 = A | last6 = Gunn | first6 = RN | last7 = Holden | first7 = J | last8 = Houle | first8 = S | last9 = Huang | first9 = SC | last10 = Ichise | first10 = Masanori | last11 = Iida | first11 = Hidehiro | last12 = Ito | first12 = Hiroshi | last13 = Kimura | first13 = Yuichi | last14 = Koeppe | first14 = Robert A | last15 = Knudsen | first15 = Gitte M | last16 = Knuuti | first16 = Juhani | last17 = Lammertsma | first17 = Adriaan A | last18 = Laruelle | first18 = Marc | last19 = Logan | first19 = Jean | last20 = Maguire | first20 = Ralph Paul | last21 = Mintun | first21 = Mark A | last22 = Morris | first22 = Evan D | last23 = Parsey | first23 = Ramin | last24 = Price | first24 = Julie C | last25 = Slifstein | first25 = Mark | last26 = Sossi | first26 = Vesna | last27 = Suhara | first27 = Tetsuya | last28 = Votaw | first28 = John R | last29 = Wong | first29 = Dean F | last30 = Carson | first30 = Richard E | display-authors = 8 |last1 = Innis|first1 = R.B.| doi-access = free }}</ref> * ''Tissue free fraction'' (ƒ<sub>ND</sub>), previously referred to as ƒ<sub>2</sub><ref name="GunnR2002Positron"/>
The ''plasma free fraction'' is the fraction of the ligand at equilibrium in blood plasma that is not bound to plasma proteins.
==See also== * Binding potential
==References== {{Reflist}}
===Others=== * {{Cite journal |vauthors=Milak MS, Severance AJ, Ogden RT, Prabhakaran J, Kumar JS, Majo VJ, Mann JJ, Parsey RV |title=Modeling Considerations for 11C-CUMI-101, an Agonist Radiotracer for Imaging Serotonin 1A Receptor In Vivo with PET |journal=J. Nucl. Med. |volume = 49 |issue = 4 |pages = 587–596 |year = 2008 |pmid = 18344443 |doi = 10.2967/jnumed.107.046540 |pmc=3580231 }}
Category:Pharmacokinetics
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