ABSTRACT
Results in Table 2 show that the concentration of Ca2+ in the cytosol of cells at rest [ Ca 2 i + ] https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781351070362/206557b3-8ca1-434e-8bd4-d1f93d700886/content/eq3.tif"/> is on the order of 10−7 M. Since the concentration in the surrounding media [ Ca 2 0 + ] https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781351070362/206557b3-8ca1-434e-8bd4-d1f93d700886/content/eq4.tif"/> is near 10−3 M, the influx of [ Ca 2 0 + ] https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781351070362/206557b3-8ca1-434e-8bd4-d1f93d700886/content/eq5.tif"/> is favored by a concentration ratio [ Ca 2 0 + ] / [ Ca 2 i + ] https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9781351070362/206557b3-8ca1-434e-8bd4-d1f93d700886/content/eq6.tif"/> close to 104. To this it has to be added the membrane potential, negative in the cell interior.
