 |
|
 |
Optical monitoring of ion transport
mechanisms in epithelia.
One of the crucial problems facing all epithelial
cells is the control of the intracellular milieu. In an effort to maintain
ionic homeostasis epithelial cells have devised a variety of channels
and carriers to regulate intracellular ionic concentrations. To further
understand how ions are transported in epithelial cells we have developed
a variety of optical techniques to continuously monitor intracellular
ionic concentrations. Using a combination of high resolution digital
video microscopy, confocal microscopy, and atomic force microscopy we
are presently able to monitor intracellular Ca2+, Na+, K+, Cl-, pH,
and membrane potential. We are currently investigating various aspects
of renal tubule ion transport, regulation of acid secretion in isolated
gastric glands, and characterization of the secretory and reabsorptive
properties of the colonic crypt.
 Figure
caption:
Atomic force microscope scan of the apical
membrane of a gastric parietal cell
Recent publications:
Kirchhoff P, Dave MH, Remy C, Kosiek O, Busque SM, Dufner M, Geibel JP, Verrey F and Wagner CA. An amino acid transporter involved in gastric acid secretion. Pflugers Arch 2005.
Finberg KE, Wagner CA, Bailey MA, Paunescu TG, Breton S, Brown D, Giebisch G, Geibel JP and Lifton RP. The B1-subunit of the H(+) ATPase is required for maximal urinary acidification. Proc Natl Acad Sci U S A 102: 13616-13621, 2005.
Geibel JP. Role of potassium in acid secretion. World J Gastroenterol 11: 5259-5265, 2005.
Dufner MM, Kirchhoff P, Remy C, Hafner P, Muller MK, Cheng SX, Tang LQ, Hebert SC, Geibel JP and Wagner CA. The calcium-sensing receptor acts as a modulator of gastric acid secretion in freshly isolated human gastric glands. Am J Physiol Gastrointest Liver Physiol 289: G1084-G1090, 2005.
Busque SM, Kerstetter JE, Geibel JP and Insogna K. L-type amino acids stimulate gastric acid secretion by activation of the calcium-sensing receptor in parietal cells. Am J Physiol Gastrointest Liver Physiol 289: G664-G669, 2005.
Geibel JP. Secretion and absorption by colonic crypts. Annu Rev Physiol 67: 471-490, 2005.
Vidyasagar S, Barmeyer C, Geibel J, Binder HJ and Rajendran VM. Role of short-chain fatty acids in colonic HCO(3) secretion. Am J Physiol Gastrointest Liver Physiol 288: G1217-G1226, 2005.
Hoffman JF and Geibel JP. Fluorescent imaging of Cl- in Amphiuma red blood cells: how the nuclear exclusion of Cl- affects the plasma membrane potential. Proc Natl Acad Sci U S A 102: 921-926, 2005.
Wagner CA, Finberg KE, Breton S, Marshansky V, Brown D and Geibel JP. Renal vacuolar H+-ATPase. Physiol Rev 84: 1263-1314, 2004.
Hebert SC , Cheng S and Geibel J. Functions and roles of the extracellular Ca2+-sensing receptor in the gastrointestinal tract. Cell Calcium 35: 239-247, 2004.
Winter C, Schulz N, Giebisch G, Geibel JP and Wagner CA. Nongenomic stimulation of vacuolar H+-ATPases in intercalated renal tubule cells by aldosterone. Proc Natl Acad Sci U S A 101: 2636-2641, 2004.
Cheng SX, Geibel JP and Hebert SC. Extracellular polyamines regulate fluid secretion in rat colonic crypts via the extracellular calcium-sensing receptor. Gastroenterology 126: 148-158, 2004.
john.geibel@yale.edu
|
|