Editing Intracellular pH (section)

{{Technical|date=March 2020}}
[[File:Membrane_pH_gradient.jpg|thumb|pH gradient across a membrane, with protons traveling through a transporter embedded in the membrane.|alt=|200x200px]]
'''Intracellular pH''' ('''pH<sub>i</sub>''') is the measure of the [[acidity]] or [[basicity]] (i.e., [[pH]]) of [[intracellular fluid]]. The pH<sub>i</sub> plays a critical role in membrane transport and other intracellular processes. In an environment with the improper pH<sub>i</sub>, biological cells may have compromised function.<ref>{{cite journal |last1=Harguindey |first1=S |last2=Stanciu |first2=D |last3=Devesa |first3=J |last4=Alfarouk |first4=K |last5=Cardone |first5=RA |last6=Polo Orozco |first6=JD |last7=Devesa |first7=P |last8=Rauch |first8=C |last9=Orive |first9=G |last10=Anitua |first10=E |last11=Roger |first11=S |last12=Reshkin |first12=SJ |title=Cellular acidification as a new approach to cancer treatment and to the understanding and therapeutics of neurodegenerative diseases. |journal=Seminars in Cancer Biology |date=April 2017 |volume=43 |pages=157–179 |doi=10.1016/j.semcancer.2017.02.003 |pmid=28193528|url=http://eprints.nottingham.ac.uk/43674/ }}</ref><ref>{{cite journal | vauthors = Flinck M, Kramer SH, Pedersen SF | title = Roles of pH in control of cell proliferation | journal = Acta Physiologica | volume = 223 | issue = 3 | pages = e13068 | date = July 2018 | pmid = 29575508 | doi = 10.1111/apha.13068 | s2cid = 4874638 }}</ref> Therefore, pH<sub>i</sub> is closely regulated in order to ensure proper cellular function, controlled cell growth, and normal cellular processes.<ref name=":0" /> The mechanisms that regulate pH<sub>i</sub> are usually considered to be [[plasma membrane]] transporters of which two main types exist — those that are dependent and those that are independent of the concentration of [[bicarbonate]] ({{chem|HCO|3|-}}). Physiologically normal intracellular pH is most commonly between 7.0 and 7.4, though there is variability between tissues (e.g., mammalian skeletal muscle tends to have a pH<sub>i</sub> of 6.8–7.1).<ref>{{cite web | first = Kerry | last = Brandis | name-list-style = vanc | work = Acid-Base Physiology | title = 2.6 Regulation of Intracellular Hydrogen Ion Concentration | url = https://www.anaesthesiamcq.com/AcidBaseBook/ab2_6.php | publisher = Anaesthesia Education Website }}</ref><ref>{{cite journal | vauthors = Madshus IH | title = Regulation of intracellular pH in eukaryotic cells | journal = The Biochemical Journal | volume = 250 | issue = 1 | pages = 1–8 | date = February 1988 | pmid = 2965576 | pmc = 1148806 | doi = 10.1042/bj2500001 }}</ref> There is also pH variation across different [[organelle]]s, which can span from around 4.5 to 8.0.<ref name=":2">{{cite journal | vauthors = Asokan A, Cho MJ | title = Exploitation of intracellular pH gradients in the cellular delivery of macromolecules | journal = Journal of Pharmaceutical Sciences | volume = 91 | issue = 4 | pages = 903–13 | date = April 2002 | pmid = 11948528 | doi = 10.1002/jps.10095 }}</ref><ref>{{cite journal | vauthors = Proksch E | title = pH in nature, humans and skin | journal = The Journal of Dermatology | volume = 45 | issue = 9 | pages = 1044–1052 | date = September 2018 | pmid = 29863755 | doi = 10.1111/1346-8138.14489 | doi-access = free }}</ref> pH<sub>i</sub> can be measured in a number of different ways.<ref name=":0">{{cite journal | vauthors = Boron WF | title = Regulation of intracellular pH | journal = Advances in Physiology Education | volume = 28 | issue = 1–4 | pages = 160–79 | date = December 2004 | pmid = 15545345 | doi = 10.1152/advan.00045.2004 | s2cid = 13242391 }}
</ref><ref>{{cite journal | vauthors = Demuth C, Varonier J, Jossen V, Eibl R, Eibl D | title = Novel probes for pH and dissolved oxygen measurements in cultivations from millilitre to benchtop scale | journal = Applied Microbiology and Biotechnology | volume = 100 | issue = 9 | pages = 3853–63 | date = May 2016 | pmid = 26995606 | doi = 10.1007/s00253-016-7412-0 | s2cid = 8434413 | hdl = 11475/2259 | hdl-access = free }}</ref>