%0 Journal Article %1 Wagn_1994_447 %A Wagner, J. %A Keizer, J. %D 1994 %J Biophys. J. %K 7919012 Acid, Animals, Biological, Buffers, Calcium, Cations, Divalent, Dyes, Egtazic Factors, Fluorescent Fura-2, Gov't, Kinetics, Mathematics, Models, Non-P.H.S., Non-U.S. Oscillometry, Research Support, Time U.S. %N 1 %P 447--456 %T Effects of rapid buffers on Ca$^2+$ diffusion and Ca$^2+$ oscillations. %U http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=7919018 %V 67 %X Based on realistic mechanisms of Ca$^2+$ buffering that include both stationary and mobile buffers, we derive and investigate models of Ca$^2+$ diffusion in the presence of rapid buffers. We obtain a single transport equation for Ca$^2+$ that contains the effects caused by both stationary and mobile buffers. For stationary buffers alone, we obtain an expression for the effective diffusion constant of Ca$^2+$ that depends on local Ca$^2+$ concentrations. Mobile buffers, such as fura-2, BAPTA, or small endogenous proteins, give rise to a transport equation that is no longer strictly diffusive. Calculations are presented to show that these effects can modify greatly the manner and rate at which Ca$^2+$ diffuses in cells, and we compare these results with recent measurements by Allbritton et al. (1992). As a prelude to work on Ca$^2+$ waves, we use a simplified version of our model of the activation and inhibition of the IP3 receptor Ca$^2+$ channel in the ER membrane to illustrate the way in which Ca$^2+$ buffering can affect both the amplitude and existence of Ca$^2+$ oscillations.

@article{Wagn_1994_447, abstract = {Based on realistic mechanisms of {C}a$^{2+}$ buffering that include both stationary and mobile buffers, we derive and investigate models of {C}a$^{2+}$ diffusion in the presence of rapid buffers. We obtain a single transport equation for {C}a$^{2+}$ that contains the effects caused by both stationary and mobile buffers. For stationary buffers alone, we obtain an expression for the effective diffusion constant of {C}a$^{2+}$ that depends on local {C}a$^{2+}$ concentrations. Mobile buffers, such as fura-2, BAPTA, or small endogenous proteins, give rise to a transport equation that is no longer strictly diffusive. Calculations are presented to show that these effects can modify greatly the manner and rate at which {C}a$^{2+}$ diffuses in cells, and we compare these results with recent measurements by Allbritton et al. (1992). As a prelude to work on {C}a$^{2+}$ waves, we use a simplified version of our model of the activation and inhibition of the IP3 receptor {C}a$^{2+}$ channel in the ER membrane to illustrate the way in which {C}a$^{2+}$ buffering can affect both the amplitude and existence of {C}a$^{2+}$ oscillations.}, added-at = {2009-06-03T11:20:58.000+0200}, author = {Wagner, J. and Keizer, J.}, biburl = {https://www.bibsonomy.org/bibtex/209ce68b18b4fe9e93afe45eb3a1112a1/hake}, description = {The whole bibliography file I use.}, file = {Wagn_1994_447.pdf:Wagn_1994_447.pdf:PDF}, interhash = {1a32636d96ea88322e00b089382e90f9}, intrahash = {09ce68b18b4fe9e93afe45eb3a1112a1}, journal = {Biophys. J.}, key = 86, keywords = {7919012 Acid, Animals, Biological, Buffers, Calcium, Cations, Divalent, Dyes, Egtazic Factors, Fluorescent Fura-2, Gov't, Kinetics, Mathematics, Models, Non-P.H.S., Non-U.S. Oscillometry, Research Support, Time U.S.}, month = Jul, number = 1, pages = {447--456}, pmid = {7919012}, timestamp = {2009-06-03T11:21:36.000+0200}, title = {Effects of rapid buffers on {C}a$^{2+}$ diffusion and {C}a$^{2+}$ oscillations.}, url = {http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=7919018}, volume = 67, year = 1994 }