Editing Lithium (section)

=== Biological ===
{{See also|Potassium in biology|Sodium in biology|Soil salinity}}
Lithium is found in trace amount in numerous plants, plankton, and invertebrates, at concentrations of 69 to 5,760 [[parts per billion]] (ppb). In vertebrates the concentration is slightly lower, and nearly all vertebrate tissue and body fluids contain lithium ranging from 21 to 763 ppb.<ref name="enc" /> Marine organisms tend to bioaccumulate lithium more than terrestrial organisms.<ref>{{cite journal |last1=Chassard-Bouchaud |first1=C. |last2=Galle |first2=P. |last3=Escaig |first3=F. |last4=Miyawaki |first4=M. |title=Bioaccumulation of lithium by marine organisms in European, American, and Asian coastal zones: microanalytic study using secondary ion emission |journal=Comptes Rendus de l'Académie des Sciences, Série III |volume=299 |issue=18 |pages=719–24 |date=1984 |pmid=6440674}}</ref> Whether lithium has a physiological role in any of these organisms is unknown.<ref name="enc">{{cite web |url=http://www.enclabs.com/lithium.html |access-date=15 October 2010 |title=Some Facts about Lithium |publisher=ENC Labs |url-status=live |archive-url=https://web.archive.org/web/20110710191644/http://www.enclabs.com/lithium.html |archive-date=10 July 2011}}</ref>
Lithium [[Composition of the human body|concentrations in human tissue]] averages about 24 [[Parts per billion|ppb]] (4 ppb in [[blood]], and 1.3 [[Parts per million|ppm]] in [[bone]]).<ref name="Emsley2011">{{cite book |last=Emsley |first=John |author-link=John Emsley |title=Nature's Building Blocks: An A-Z Guide to the Elements |url=https://books.google.com/books?id=2EfYXzwPo3UC&pg=PA290 |access-date=17 June 2016 |date=25 August 2011 |publisher=OUP Oxford |isbn=978-0-19-960563-7 |pages=290–298 |archive-date=26 August 2023 |archive-url=https://web.archive.org/web/20230826192732/https://books.google.com/books?id=2EfYXzwPo3UC&pg=PA290 |url-status=live}}</ref>

Lithium is easily absorbed by [[plant]]s<ref name="Emsley2011" /> and lithium concentration in plant tissue is typically around 1 [[Part per million|ppm]].<ref name="Lithium and Cell Physiology 1990 Ch. 3 Lithium in Plants" /> Some plant [[Family (biology)|families]] [[Bioaccumulation|bioaccumulate]] more lithium than others.<ref name="Lithium and Cell Physiology 1990 Ch. 3 Lithium in Plants" /> [[Dry weight]] lithium concentrations for members of the [[Family (biology)|family]] [[Solanaceae]] (which includes [[potato]]es and [[tomato]]es), for instance, can be as high as 30 ppm while this can be as low as 0.05 ppb for [[Corn (grain)|corn grains]].<ref name="Emsley2011" />
Studies of lithium concentrations in mineral-rich soil give ranges between around 0.1 and 50−100 [[Parts per million|ppm]], with some concentrations as high as 100−400 ppm, although it is unlikely that all of it is available for uptake by [[plant]]s.<ref name="Lithium and Cell Physiology 1990 Ch. 3 Lithium in Plants">{{cite book |editor-last=Bach |editor-first=Ricardo O. |editor-last2=Gallicchio |editor-first2=Vincent S. |title=Lithium and Cell Physiology |publisher=Springer New York |publication-place=New York, NY |year=1990 |isbn=978-1-4612-7967-9 |doi=10.1007/978-1-4612-3324-4 |pages=25–46 |s2cid=44374126}}</ref>
Lithium accumulation does not appear to affect the [[essential nutrient]] composition of plants.<ref name="Lithium and Cell Physiology 1990 Ch. 3 Lithium in Plants" /> Tolerance to lithium varies by plant species and typically parallels [[Halotolerance|sodium tolerance]]; [[maize]] and [[Rhodes grass]], for example, are highly tolerant to lithium injury while [[avocado]] and [[soybean]] are very sensitive.<ref name="Lithium and Cell Physiology 1990 Ch. 3 Lithium in Plants" /> Similarly, lithium at concentrations of 5 ppm reduces [[seed germination]] in some species (e.g. [[Oryza sativa|Asian rice]] and [[chickpea]]) but not in others (e.g. [[barley]] and [[wheat]]).<ref name="Lithium and Cell Physiology 1990 Ch. 3 Lithium in Plants" />

Many of lithium's major biological effects can be explained by its competition with other ions.<ref name="Jakobsson Argüello-Miranda Chiu Fazal pp. 587–604">{{cite journal |last1=Jakobsson |first1=Eric |last2=Argüello-Miranda |first2=Orlando |last3=Chiu |first3=See-Wing |last4=Fazal |first4=Zeeshan |last5=Kruczek |first5=James |last6=Nunez-Corrales |first6=Santiago |last7=Pandit |first7=Sagar |last8=Pritchet |first8=Laura |title=Towards a Unified Understanding of Lithium Action in Basic Biology and its Significance for Applied Biology |journal=[[The Journal of Membrane Biology]] |publisher=Springer Science and Business Media LLC |volume=250 |issue=6 |date=2017-11-10 |issn=0022-2631 |doi=10.1007/s00232-017-9998-2 |pmid=29127487 |pages=587–604 |pmc=5696506}}</ref>
The [[Monovalent ion|monovalent]] lithium [[Cation|ion]] {{chem|Li|+}} competes with other ions such as [[sodium]] (immediately below lithium on the [[periodic table]]), which like lithium is also a monovalent [[alkali metal]].
Lithium also competes with [[Bivalent (chemistry)|bivalent]] [[magnesium]] ions, whose [[ionic radius]] (86 [[Picometre|pm]]) is approximately that of the lithium ion<ref name="Jakobsson Argüello-Miranda Chiu Fazal pp. 587–604" /> (90 pm).
Mechanisms that transport sodium across cellular membranes also transport lithium.
For instance, [[sodium channel]]s (both [[Voltage-gated sodium channel|voltage-gated]] and [[Epithelial sodium channel|epithelial]]) are particularly major pathways of entry for lithium.<ref name="Jakobsson Argüello-Miranda Chiu Fazal pp. 587–604" />
Lithium ions can also [[permeate]] through [[ligand-gated ion channel]]s as well as cross both [[Nuclear membrane|nuclear]] and [[Mitochondrion|mitochondrial]] [[membrane]]s.<ref name="Jakobsson Argüello-Miranda Chiu Fazal pp. 587–604" />
Like sodium, lithium can enter and partially block (although not [[permeate]]) [[potassium channel]]s and [[calcium channel]]s.<ref name="Jakobsson Argüello-Miranda Chiu Fazal pp. 587–604" />
The biological effects of lithium are many and varied but its [[Mechanism of action|mechanisms of action]] are only partially understood.<ref name="Alda pp. 661–670">{{cite journal |last=Alda |first=M |title=Lithium in the treatment of bipolar disorder: pharmacology and pharmacogenetics |journal=[[Molecular Psychiatry]] |publisher=[[Nature Publishing Group]] |volume=20 |issue=6 |date=17 February 2015 |issn=1359-4184 |doi=10.1038/mp.2015.4 |pages=661–670 |pmid=25687772 |pmc=5125816}}</ref>
For instance, studies of [[Lithium (medication)|lithium-treated]] patients with [[bipolar disorder]] show that, among many other effects, lithium partially reverses [[telomere]] [[Telomere shortening|shortening]] in these patients and also increases mitochondrial function, although how lithium produces these [[pharmacological effect]]s is not understood.<ref name="Alda pp. 661–670" /><ref name="Martinsson Wei Xu Melas 2013 pp. e261–e261">{{cite journal |last1=Martinsson |first1=L |last2=Wei |first2=Y |last3=Xu |first3=D |last4=Melas |first4=P A |last5=Mathé |first5=A A |last6=Schalling |first6=M |last7=Lavebratt |first7=C |last8=Backlund |first8=L |title=Long-term lithium treatment in bipolar disorder is associated with longer leukocyte telomeres |journal=[[Translational Psychiatry]] |publisher=[[Nature Publishing Group]] |volume=3 |issue=5 |year=2013 |issn=2158-3188 |doi=10.1038/tp.2013.37 |pages=e261– |pmid=23695236 |pmc=3669924}}</ref>
Even the exact mechanisms involved in [[lithium toxicity]] are not fully understood.