ISSN:
1432-1424
Keywords:
Key words: Pancreatic duct — Mathematical model — HCO−3 secretion — Intracellular pH regulation — Cystic fibrosis transmembrane conductance regulator
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract. A mathematical model of the HCO− 3-secreting pancreatic ductal epithelium was developed using network thermodynamics. With a minimal set of assumptions, the model accurately reproduced the experimentally measured membrane potentials, voltage divider ratio, transepithelial resistance and short-circuit current of nonstimulated ducts that were microperfused and bathed with a CO2/HCO− 3-free, HEPES-buffered solution, and also the intracellular pH of duct cells bathed in a CO2/HCO− 3-buffered solution. The model also accurately simulated: (i) the effect of step changes in basolateral K+ concentration, and the effect of K+ channel blockers on basolateral membrane potential; (ii) the intracellular acidification caused by a Na+-free extracellular solution and the effect of amiloride on this acidification; and (iii) the intracellular alkalinization caused by a Cl−-free extracellular solution and the effect of DIDS on this alkalinization. In addition, the model predicted that the luminal Cl− conductance plays a key role in controlling both the HCO− 3 secretory rate and intracellular pH during HCO− 3 secretion. We believe that the model will be helpful in the analysis of experimental data and improve our understanding of HCO− 3-transporting mechanisms in pancreatic duct cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002329900132
