fbpx
Wikipedia

Calcium buffering

Calcium buffering describes the processes which help stabilise the concentration of free calcium ions within cells, in a similar manner to how pH buffers maintain a stable concentration of hydrogen ions.[1] The majority of calcium ions within the cell are bound to intracellular proteins, leaving a minority freely dissociated.[2] When calcium is added to or removed from the cytoplasm by transport across the cell membrane or sarcoplasmic reticulum, calcium buffers minimise the effect on changes in cytoplasmic free calcium concentration by binding calcium to or releasing calcium from intracellular proteins. As a result, 99% of the calcium added to the cytosol of a cardiomyocyte during each cardiac cycle becomes bound to calcium buffers, creating a relatively small change in free calcium.[2]

The regulation of free calcium is of particular importance in excitable cells like cardiomyocytes[3] and neurons.[4] Within these cells, many intracellular proteins can act as calcium buffers. In cardiac muscle cells, the most important buffers within the cytoplasm include troponin C, SERCA, calmodulin, and myosin, while the most important within calcium buffer within the sarcoplasmic reticulum is calsequestrin.[2][5], The effects of calcium buffers depends on their affinity for calcium, as well as the speed with which they bind and release it. [6]

Clinical significance edit

Alterations in calcium buffering within the cytosol have been implicated in the tendency to arrhythmias (abnormal cardiac rhythms) in some genetic mutations known to cause hypertrophic cardiomyopathy.[7] Genetic mutations affecting calsequestrin are responsible for an autosomal recessive form of catecholaminergic polymorphic ventricular tachycardia, an inherited cardiac condition that can lead to sudden death.[8] Calcium buffering within atrial myocytes is affected by ageing in large animal models, elevating sarcoplasmic reticulum calcium content, which could potentially contribute towards a tendency to atrial fibrillation.[9]

See also edit

References edit

  1. ^ Gilabert JA (2012). "Cytoplasmic calcium buffering". Advances in Experimental Medicine and Biology. 740: 483–98. doi:10.1007/978-94-007-2888-2_20. ISBN 978-94-007-2887-5. PMID 22453955. {{cite journal}}: Cite journal requires |journal= (help)
  2. ^ a b c M., Bers, D. (2001). Excitation-contraction coupling and cardiac contractile force (2nd ed.). Dordrecht: Kluwer Academic Publishers. ISBN 9780792371588. OCLC 47659382.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. ^ Smith GL, Eisner DA (May 2019). "Calcium Buffering in the Heart in Health and Disease". Circulation. 139 (20): 2358–2371. doi:10.1161/CIRCULATIONAHA.118.039329. PMC 6520234. PMID 31082292.
  4. ^ Schwaller B (November 2010). "Cytosolic Ca2+ buffers". Cold Spring Harbor Perspectives in Biology. 2 (11): a004051. doi:10.1101/cshperspect.a004051. PMC 2964180. PMID 20943758.
  5. ^ Briston SJ, Dibb KM, Solaro RJ, Eisner DA, Trafford AW (November 2014). "Balanced changes in Ca buffering by SERCA and troponin contribute to Ca handling during β-adrenergic stimulation in cardiac myocytes". Cardiovascular Research. 104 (2): 347–54. doi:10.1093/cvr/cvu201. PMC 4240166. PMID 25183792.
  6. ^ Eisner, David; Neher, Erwin; Taschenberger, Holger; Smith, Godfrey (2023-06-16). "Physiology of intracellular calcium buffering". Physiological Reviews. doi:10.1152/physrev.00042.2022. ISSN 1522-1210. PMID 37326298. S2CID 259174431.
  7. ^ Schober T, Huke S, Venkataraman R, Gryshchenko O, Kryshtal D, Hwang HS, Baudenbacher FJ, Knollmann BC (July 2012). "Myofilament Ca sensitization increases cytosolic Ca binding affinity, alters intracellular Ca homeostasis, and causes pause-dependent Ca-triggered arrhythmia". Circulation Research. 111 (2): 170–9. doi:10.1161/CIRCRESAHA.112.270041. PMC 3393041. PMID 22647877.
  8. ^ Lieve KV, van der Werf C, Wilde AA (May 2016). "Catecholaminergic Polymorphic Ventricular Tachycardia". Circulation Journal. 80 (6): 1285–91. doi:10.1253/circj.CJ-16-0326. PMID 27180891.
  9. ^ Clarke JD, Caldwell JL, Pearman CM, Eisner DA, Trafford AW, Dibb KM (October 2017). "2+ handling in old sheep atrial myocytes". The Journal of Physiology. 595 (19): 6263–6279. doi:10.1113/JP274053. PMC 5621500. PMID 28752958.

calcium, buffering, describes, processes, which, help, stabilise, concentration, free, calcium, ions, within, cells, similar, manner, buffers, maintain, stable, concentration, hydrogen, ions, majority, calcium, ions, within, cell, bound, intracellular, protein. Calcium buffering describes the processes which help stabilise the concentration of free calcium ions within cells in a similar manner to how pH buffers maintain a stable concentration of hydrogen ions 1 The majority of calcium ions within the cell are bound to intracellular proteins leaving a minority freely dissociated 2 When calcium is added to or removed from the cytoplasm by transport across the cell membrane or sarcoplasmic reticulum calcium buffers minimise the effect on changes in cytoplasmic free calcium concentration by binding calcium to or releasing calcium from intracellular proteins As a result 99 of the calcium added to the cytosol of a cardiomyocyte during each cardiac cycle becomes bound to calcium buffers creating a relatively small change in free calcium 2 The regulation of free calcium is of particular importance in excitable cells like cardiomyocytes 3 and neurons 4 Within these cells many intracellular proteins can act as calcium buffers In cardiac muscle cells the most important buffers within the cytoplasm include troponin C SERCA calmodulin and myosin while the most important within calcium buffer within the sarcoplasmic reticulum is calsequestrin 2 5 The effects of calcium buffers depends on their affinity for calcium as well as the speed with which they bind and release it 6 Clinical significance editAlterations in calcium buffering within the cytosol have been implicated in the tendency to arrhythmias abnormal cardiac rhythms in some genetic mutations known to cause hypertrophic cardiomyopathy 7 Genetic mutations affecting calsequestrin are responsible for an autosomal recessive form of catecholaminergic polymorphic ventricular tachycardia an inherited cardiac condition that can lead to sudden death 8 Calcium buffering within atrial myocytes is affected by ageing in large animal models elevating sarcoplasmic reticulum calcium content which could potentially contribute towards a tendency to atrial fibrillation 9 See also editCalcium channel Cellular communication biology Excitation contraction coupling Protein dynamicsReferences edit Gilabert JA 2012 Cytoplasmic calcium buffering Advances in Experimental Medicine and Biology 740 483 98 doi 10 1007 978 94 007 2888 2 20 ISBN 978 94 007 2887 5 PMID 22453955 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help a b c M Bers D 2001 Excitation contraction coupling and cardiac contractile force 2nd ed Dordrecht Kluwer Academic Publishers ISBN 9780792371588 OCLC 47659382 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Smith GL Eisner DA May 2019 Calcium Buffering in the Heart in Health and Disease Circulation 139 20 2358 2371 doi 10 1161 CIRCULATIONAHA 118 039329 PMC 6520234 PMID 31082292 Schwaller B November 2010 Cytosolic Ca2 buffers Cold Spring Harbor Perspectives in Biology 2 11 a004051 doi 10 1101 cshperspect a004051 PMC 2964180 PMID 20943758 Briston SJ Dibb KM Solaro RJ Eisner DA Trafford AW November 2014 Balanced changes in Ca buffering by SERCA and troponin contribute to Ca handling during b adrenergic stimulation in cardiac myocytes Cardiovascular Research 104 2 347 54 doi 10 1093 cvr cvu201 PMC 4240166 PMID 25183792 Eisner David Neher Erwin Taschenberger Holger Smith Godfrey 2023 06 16 Physiology of intracellular calcium buffering Physiological Reviews doi 10 1152 physrev 00042 2022 ISSN 1522 1210 PMID 37326298 S2CID 259174431 Schober T Huke S Venkataraman R Gryshchenko O Kryshtal D Hwang HS Baudenbacher FJ Knollmann BC July 2012 Myofilament Ca sensitization increases cytosolic Ca binding affinity alters intracellular Ca homeostasis and causes pause dependent Ca triggered arrhythmia Circulation Research 111 2 170 9 doi 10 1161 CIRCRESAHA 112 270041 PMC 3393041 PMID 22647877 Lieve KV van der Werf C Wilde AA May 2016 Catecholaminergic Polymorphic Ventricular Tachycardia Circulation Journal 80 6 1285 91 doi 10 1253 circj CJ 16 0326 PMID 27180891 Clarke JD Caldwell JL Pearman CM Eisner DA Trafford AW Dibb KM October 2017 2 handling in old sheep atrial myocytes The Journal of Physiology 595 19 6263 6279 doi 10 1113 JP274053 PMC 5621500 PMID 28752958 Retrieved from https en wikipedia org w index php title Calcium buffering amp oldid 1183905110, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.