Calcium: A program in basic for calculating the composition of solutions with specified free concentrations of calcium, magnesium and other divalent cations

Chang, Dean; Hsieh, Paul S.; Dawson, David C.

doi:10.1016/0010-4825(88)90022-4

Cited by 90 publications

(35 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The standard intracellular (pipette) solution contained: 130 mmol/L KCl, 10 mmol/L NaCl, 2 mmol/L MgCl 2 , 10 mmol/L HEPES/KOH, 1 mmol/L ATP, 0.5 mmol/L CaCl 2 , and 1 mmol/L ethylene glycol-bis(␤-aminoethyl ether)-N,N-tetraacetic acid (EGTA) (pH 7.3), corresponding to a free [Ca 2ϩ ] of Ϸ100 nmol/L. 36 The reversal potentials for K ϩ (E K ) and Cl Ϫ (E Cl ) are Ϫ82 and Ϫ1 mV, respectively. Macroscopic currents carried by Cl Ϫ (I Cl ) were measured at a test potential of Ϫ80 mV, near the reversal potential for K ϩ .…”

Section: Methodsmentioning

confidence: 99%

Activation of protein kinase Cα couples cell volume to membrane Cl− permeability in HTC hepatoma and Mz-ChA-1 cholangiocarcinoma cells

et al. 1998

View full text Add to dashboard Cite

Physiological increases in liver cell volume lead to an adaptive response that includes opening of membrane Cl ؊ channels, which is critical for volume recovery. The purpose of these studies was to assess the potential role for protein kinase C (PKC) as a signal involved in cell volume homeostasis. Studies were performed in HTC rat hepatoma and Mz-ChA-1 human cholangiocarcinoma cells, which were used as model hepatocytes and cholangiocytes, respectively. In each cell type, cell volume increases were followed by: 1) translocation of PKC␣ from cytosolic to particulate (membrane) fractions; 2) a 10-to 40-fold increase in whole-cell membrane Cl ؊ current density; and 3) partial recovery of cell volume. In HTC cells, the volume-dependent Cl Liver cells play a central role in systemic metabolic balance and bile formation, with high capacities for protein synthesis, gluconeogenesis, and vectorial secretion of organic solutes and electrolytes into bile. These and other specialized functions are rapidly and precisely regulated by circulating hormones and substrate availability to meet changing physiological demands. Previous studies indicate that hormonal control of metabolic function requires selective modulation of membrane ion permeability, which changes of 10-to 50-fold following receptor stimulation.

show abstract

Section: Methodsmentioning

confidence: 99%

Activation of protein kinase Cα couples cell volume to membrane Cl− permeability in HTC hepatoma and Mz-ChA-1 cholangiocarcinoma cells

et al. 1998

View full text Add to dashboard Cite

show abstract

“…Membrane K ϩ currents were measured using whole-cell and cell-attached patch clamp recording techniques (17) as previously described (18,19). Cover slips containing cells were mounted in a chamber (volume ‫ف‬ 400 l) and were perfused at 4-5 ml/min with a standard extracellular solution containing (mM): 140 NaCl, ] of ‫ف‬ 100 nM (20). Movement of positive charge out of the pipette is shown as an upward deflection of the current trace.…”

Section: Methodsmentioning

confidence: 99%

Cytosolic Ca2+ and protein kinase Calpha couple cellular metabolism to membrane K+ permeability in a human biliary cell line.

Wang¹,

Roman²,

Schlenker³

et al. 1997

J. Clin. Invest.

View full text Add to dashboard Cite

Cholangiocytes represent an important target of injury during the ischemia and metabolic stress that accompanies liver preservation. Since K ϩ efflux serves to minimize injury during ATP depletion in certain other cell types, the purpose of these studies was to evaluate the effects of ATP depletion on plasma membrane K ϩ permeability of Mz-ChA-1 cells, a model human biliary cell line. Cells were exposed to dinitrophenol (

show abstract

“…Epithelial sheets were isolated from the ventral skin of Rana esculenta and Rana temporaria using collagenase to separate the corium. The isolated epithelium was cut into four discs (1 6 cm2 (Chang, Hsieh & Dawson, 1988). All chemicals were purchased from Sigma.…”

Section: Patch-clamp Recordingmentioning

confidence: 99%

Cross‐talk between ATP‐regulated K+ channels and Na+ transport via cellular metabolism in frog skin principal cells.

Urbach

Kerkhove

Maguire

et al. 1996

The Journal of Physiology

View full text Add to dashboard Cite

1. Isolated frog skin epithelium, mounted in an Ussing chamber and bathed in standard NaClRinger solution, recycles K+ across the basolateral membrane of principal cells through an inward-rectifier K+ channel (Kir) operating in parallel with a Na+-K+-ATPase pump. Here we report on the metabolic control of the Kir channel using patch clamping, short-circuit current measurement and enzymatic determination of cellular ATP (ATP1 4. Sulphonylureas inhibit single KATP channels in cell-attached patches as well as the total basolateral K+ current measured in frog skin epithelia perforated with nystatin on the apical side.5. Na+-K+-ATPase activity is a major determinant of cytosolic ATP. Blocking the pump activity with ouabain produced a time-dependent increase in ATPi and reduced the open probability of KATP channels in cell-attached membranes. 6. We conclude that the ratio of ATP/ADP is an important metabolic coupling factor between the rate of Na+-K+ pumping and K+ recycling.The reabsorption of Na across principal cells of frog skin epithelium is mediated by passive entry through channels in the apical membrane and active secretion via an Na+-K+-ATPase localized in the basolateral membrane. In parallel with the Na+-K+ pump activity, K+ is recycled through a channel which was recently identified as an inward-rectifier K+ channel (Kir) localized in the basolateral membrane of principal cells (Urbach, Van Kerkhove & Harvey, 1994). The maintenance of equilibrium between transepithelial Nae absorption and K+ recycling involves a concerted action of cellular signals (cross-talk). Coupling between the apical Nae conductance and the basolateral K+ conductance has been described in frog skin and turtle and toad urinary bladder (Davis & Finn, 1982;Harvey, Thomas & Ehrenfeld, 1988;Dawson & Richards, 1990). These studies have demonstrated a role for membrane potential, pH and Ca2+ in mediating cross-talk. In tight epithelia, pHi has been shown to be a potent regulator of net sodium absorption via the pH sensitivity of apical Nae and basolateral K+ channels Oberleithner, Kersting & Gassner, 1988;Willumsen & Boucher, 1992;Rick, 1994 Giebisch & Welling, 1992) and cortical collecting tubule (Wang & Giebisch, 1991 METHODSShort-circuit current and basolateral membrane K+ conductance The ventral skin was dissected off doubly pithed frogs (Rana esculenta and Rana temporaria) and mounted in an Ussing-type chamber and bathed in standard amphibian Ringer solution containing (mM): 110 NaCl, 3-7 KOH, 6 Hepes, 2 CaCl2 and 1 MgCl2, pH 7*4, 260 mosmol F'). The spontaneous transepithelial voltage, measured with calomel electrodes, was clamped to 0 mV by applying a SCC using an automatic voltage-current clamp (model DVC-100, World Precision Instruments, Sarasota, FL, USA). The transepithelial Nae transport rate was estimated as equivalent to the amiloride (10 /M)-sensitive SCC. To examine the basolateral membrane conductance in isolation, the apical membrane was permeabilized using the ionophore nystatin (Kirk & Dawson, 1983;Garty, 1994). In thes...

show abstract

Calcium: A program in basic for calculating the composition of solutions with specified free concentrations of calcium, magnesium and other divalent cations

Cited by 90 publications

References 10 publications

Activation of protein kinase Cα couples cell volume to membrane Cl− permeability in HTC hepatoma and Mz-ChA-1 cholangiocarcinoma cells

Activation of protein kinase Cα couples cell volume to membrane Cl− permeability in HTC hepatoma and Mz-ChA-1 cholangiocarcinoma cells

Cytosolic Ca2+ and protein kinase Calpha couple cellular metabolism to membrane K+ permeability in a human biliary cell line.

Cross‐talk between ATP‐regulated K+ channels and Na+ transport via cellular metabolism in frog skin principal cells.

Contact Info

Product

Resources

About