Intracellular pH

pH gradient across a membrane, with protons traveling through a transporter embedded in the membrane.

Intracellular pH (pHi) is the measure of the acidity or basicity (i.e., pH) of intracellular fluid. The pHi plays a critical role in membrane transport and other intracellular processes. In an environment with the improper pHi, biological cells may have compromised function.[1][2] Therefore, pHi is closely regulated in order to ensure proper cellular function, controlled cell growth, and normal cellular processes.[3] The mechanisms that regulate pHi 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 (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 pHi of 6.8–7.1).[4][5] There is also pH variation across different organelles, which can span from around 4.5 to 8.0.[6][7] pHi can be measured in a number of different ways.[3][8]

  1. ^ Harguindey, S; Stanciu, D; Devesa, J; Alfarouk, K; Cardone, RA; Polo Orozco, JD; Devesa, P; Rauch, C; Orive, G; Anitua, E; Roger, S; Reshkin, SJ (April 2017). "Cellular acidification as a new approach to cancer treatment and to the understanding and therapeutics of neurodegenerative diseases". Seminars in Cancer Biology. 43: 157–179. doi:10.1016/j.semcancer.2017.02.003. PMID 28193528.
  2. ^ Flinck M, Kramer SH, Pedersen SF (July 2018). "Roles of pH in control of cell proliferation". Acta Physiologica. 223 (3): e13068. doi:10.1111/apha.13068. PMID 29575508. S2CID 4874638.
  3. ^ a b Boron WF (December 2004). "Regulation of intracellular pH". Advances in Physiology Education. 28 (1–4): 160–79. doi:10.1152/advan.00045.2004. PMID 15545345. S2CID 13242391.
  4. ^ Brandis K. "2.6 Regulation of Intracellular Hydrogen Ion Concentration". Acid-Base Physiology. Anaesthesia Education Website.
  5. ^ Madshus IH (February 1988). "Regulation of intracellular pH in eukaryotic cells". The Biochemical Journal. 250 (1): 1–8. doi:10.1042/bj2500001. PMC 1148806. PMID 2965576.
  6. ^ Asokan A, Cho MJ (April 2002). "Exploitation of intracellular pH gradients in the cellular delivery of macromolecules". Journal of Pharmaceutical Sciences. 91 (4): 903–13. doi:10.1002/jps.10095. PMID 11948528.
  7. ^ Proksch E (September 2018). "pH in nature, humans and skin". The Journal of Dermatology. 45 (9): 1044–1052. doi:10.1111/1346-8138.14489. PMID 29863755.
  8. ^ Demuth C, Varonier J, Jossen V, Eibl R, Eibl D (May 2016). "Novel probes for pH and dissolved oxygen measurements in cultivations from millilitre to benchtop scale". Applied Microbiology and Biotechnology. 100 (9): 3853–63. doi:10.1007/s00253-016-7412-0. hdl:11475/2259. PMID 26995606. S2CID 8434413.