Effects of gap junction to Ca(2+) and to IP(3) on the synchronization of intercellular calcium oscillations in hepatocytes.
The frequency of free cytosolic calcium concentration ([Ca(2+)]) oscillations elicited by a given agonist concentration differs between individual hepatocytes. However, in multicellular systems of rat hepatocytes and even in the intact liver, [Ca(2+)] oscillations are synchronized and highly coordinated. In this paper, we have investigated theoretically the gap junction permeable to calcium and to IP(3) on intercellular synchronization by means of a mathematical model, respectively. It is shown that gap junction permeable to calcium and to IP(3) are effective on synchronizing calcium oscillations in coupled hepatocytes. Our theoretical results are similar either for the case of Ca(2+) acting as coordinating messenger or for the case of IP(3) as coordinating messenger. There exists an optimal coupling strength for a pair of connected hepatocytes. Appropriate coupling strength and IP(3) level can induce various harmonic locking of intercellular [Ca(2+)] oscillations. Furthermore, a phase diagram in two-dimensional parameter space of the coupling strength and IP(3) level (or the velocity of IP(3) synthesis) has been predicted, in which the synchronization region is similar to Arnol'd tongue.
Wu
Dan
D
Department of Physics and Institute of Biophysics, Central China Normal University, Wuhan 430079, Hubei, China. wud@phy.ccnu.edu.cn
Jia
Ya
Y
Zhan
Xuan
X
Yang
Lijian
L
Liu
Quan
Q
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D002413:Cations, Divalent; D003600:Cytosol / Q000378:metabolism; D017629:Gap Junctions / Q000502:physiology*; D022781:Hepatocytes / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D008954:Models, Biological; D009991:Oscillometry; D051381:Rats; D013997:Time Factors
D015220:Calcium Channels; D002413:Cations, Divalent; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium