Intracellular ion concentrations and cell volume during cholinergic stimulation of eccrine secretory coil cells

1991 ◽  
Vol 119 (3) ◽  
pp. 211-219 ◽  
Author(s):  
T. Takemura ◽  
F. Sato ◽  
K. Saga ◽  
Y. Suzuki ◽  
K. Sato
Keyword(s):  
Cell Volume ◽  
Cholinergic Stimulation ◽  
Ion Concentrations ◽  
Intracellular Ion Concentrations ◽  
Secretory Coil ◽  
Stimulation Of

Characterization in vitro of H+ secretion and H+:Na+ exchange by an organism normally inhabiting a CO2-rich environment: Hymenolepis diminuta (Cestoda) in the rat intestine

1978 ◽  
Vol 56 (11) ◽  
pp. 2344-2354 ◽  
Author(s):  
R. B. Podesta
Keyword(s):  
Metabolic Pathways ◽  
Intestinal Parasite ◽  
Hymenolepis Diminuta ◽  
Ambient Fluid ◽  
Rat Intestine ◽  
Ion Concentrations ◽  
Intracellular Ion Concentrations ◽  
Metabolic Reactions ◽  
Stimulation Of

H+ and Na+ transport by the intestinal parasite Hymenolepis diminuta were studied in vitro. The flatworms acidified the ambient fluid by secreting H+ and the acidification could not be correlated with organic acid excretion. Ambient CO2-independent H+ secretion was attributed to protons of metabolic origin: dephosphorylation reactions and ionization of organic acids within the tissues. Ambient CO2-dependent H+ secretion was attributed to protons produced as a result of the hydration of CO2 within the tissue and to the stimulation of anaerobic metabolic pathways by CO2 acting as a cosubstrate in energy metabolism. Studies in which Na+ uptake was stimulated by CO2 or glucose and inhibited by ouabain, amiloride, or Na+ replacement suggested a partial direct coupling of Na+ absorption and H+ secretion but the different activation energies and the effect of buffer anions other than HCO3− suggested an indirect interaction. Various interactions were considered, including the effect of CO2 and intracellular ion concentrations on metabolic reactions leading to the supply of protons for H+ secretion and energy for ion transport.

X-ray microanalysis of intracellular ions in the anaerobic halophilic eubacterium Haloanaerobium praevalens

1997 ◽  
Vol 43 (6) ◽  
pp. 588-592 ◽  
Author(s):  
Aharon Oren ◽  
Mikal Heldal ◽  
Svein Norland
Keyword(s):  
Electron Microscope ◽  
High Variability ◽  
Sodium Potassium ◽  
X Ray ◽  
Ion Concentrations ◽  
Major Cation ◽  
Transmission Electron ◽  
Intracellular Ion Concentrations ◽  
Intracellular Ions ◽  
Chloride Concentrations

The intracellular concentrations of Na+, K+, and Cl− of the anaerobic halophilic eubacterium Haloanaerobium praevalens were assayed by means of X-ray microanalysis with the transmission electron microscope. Apparent intracellular cation concentrations between 1.22 and 1.91 M and chloride concentrations of 0.93–1.57 M were measured in cells growing exponentially in 2.6 M total salts. In exponentially growing cells, K+ was the major cation (70% of the cation sum). Stationary phase cells showed a high variability among individual cells, some of the cells containing higher Na+ than K+ concentrations.Key words: Haloanaerobium praevalens, intracellular ion concentrations, sodium, potassium, X-ray microanalysis.

scholarly journals Cholinergic stimulation of the Na+/K+ adenosine triphosphatase as revealed by microphysiometry

1993 ◽  
Vol 64 (3) ◽  
pp. 813-823 ◽  
Author(s):  
D.L. Miller ◽  
J.C. Olson ◽  
J.W. Parce ◽  
J.C. Owicki
Keyword(s):  
Adenosine Triphosphatase ◽  
Cholinergic Stimulation ◽  
Stimulation Of

scholarly journals The ionic basis of the hypo-osmotic depolarization in neurons from the opisthobranch mollusc Elysia chlorotica

1992 ◽  
Vol 163 (1) ◽  
pp. 169-186
Author(s):  
R. H. Quinn ◽  
S. K. Pierce
Keyword(s):  
Cell Volume ◽  
Time Course ◽  
The Other ◽  
Resting Potential ◽  
Ion Concentrations ◽  
Elysia Chlorotica ◽  
Apparent Relationship ◽  
Volume Recovery ◽  
Original Potential ◽  
Ionic Basis

The resting potential of identified cells (Parker cells) in the abdominal ganglion of Elysia chlorotica (Gould) depolarizes by about 30 mV in response to a 50% reduction in osmolality and returns to the original potential in 20 min. Cell volume recovery requires approximately 2 h. Thus, recovery of the resting potential is not dependent on recovery of cell volume. The hypo-osmotic depolarization persists following inhibition of the electrogenic Na+/K(+)-ATPase with ouabain, and the levels of extracellular K+ and Cl- have little effect on the magnitude of the depolarization, while decreasing extracellular Na+ concentration produces a depolarization of only 10 mV. This suggests that the hypo-osmotic depolarization in Parker cells results mostly from increased relative permeability to Na+. Following transfer from 920 to 460 mosmol kg-1, Na+, Cl- and proline betaine leave the cells while intracellular K+ is conserved. Loss of intracellular Na+ and conservation of intracellular K+ are dependent on active transport by the Na+/K(+)-ATPase. Na+ and proline betaine leave the cells with a time course that is much longer than that of the hypo-osmotic depolarization. Unlike the other solutes, most of the reduction in intracellular Cl- concentration occurs coincidentally with the hypo-osmotic depolarization. However, unlike the hypo-osmotic depolarization, bulk loss of Cl- does not require the reduction in osmolality, only the reduction in extracellular ion concentrations. There is no apparent relationship between membrane depolarization and the regulation of intracellular osmolytes in Elysia neurons following hypo-osmotic stress.

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