In:
Physiological Reviews, American Physiological Society, Vol. 103, No. 4 ( 2023-10-01), p. 2767-2845
Abstract:
Calcium signaling underlies much of physiology. Almost all the Ca 2+ in the cytoplasm is bound to buffers, with typically only ∼1% being freely ionized at resting levels in most cells. Physiological Ca 2+ buffers include small molecules and proteins, and experimentally Ca 2+ indicators will also buffer calcium. The chemistry of interactions between Ca 2+ and buffers determines the extent and speed of Ca 2+ binding. The physiological effects of Ca 2+ buffers are determined by the kinetics with which they bind Ca 2+ and their mobility within the cell. The degree of buffering depends on factors such as the affinity for Ca 2+ , the Ca 2+ concentration, and whether Ca 2+ ions bind cooperatively. Buffering affects both the amplitude and time course of cytoplasmic Ca 2+ signals as well as changes of Ca 2+ concentration in organelles. It can also facilitate Ca 2+ diffusion inside the cell. Ca 2+ buffering affects synaptic transmission, muscle contraction, Ca 2+ transport across epithelia, and the killing of bacteria. Saturation of buffers leads to synaptic facilitation and tetanic contraction in skeletal muscle and may play a role in inotropy in the heart. This review focuses on the link between buffer chemistry and function and how Ca 2+ buffering affects normal physiology and the consequences of changes in disease. As well as summarizing what is known, we point out the many areas where further work is required.
Type of Medium:
Online Resource
ISSN:
0031-9333
,
1522-1210
DOI:
10.1152/physrev.00042.2022
Language:
English
Publisher:
American Physiological Society
Publication Date:
2023
detail.hit.zdb_id:
1471693-8
SSG:
12
