Ion-selective electrode studies on the effects of 5-hydroxytryptamine on the intracellular level of potassium in an insect salivary gland

1978 ◽  
Vol 72 (1) ◽  
pp. 203-216 ◽  
Author(s):  
M. J. Berridge ◽  
W. R. Schlue
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Potassium Concentration ◽  
Ionic Composition ◽  
Fluid Secretion ◽  
Ion Selective Electrode ◽  
Intracellular Level ◽  
Rapid Loss ◽  
Selective Electrode ◽  
External Concentration

Potassium-sensitive microelectrodes were used to measure the intracellular level of potassium in Calliphora salivary glands. During stimulation with 1 X 10(−8) M 5-HT, the potassium concentration increased from a resting level of 133.2 to 139.0 mM. When the external concentration of potassium was reduced below 2mM there was a rapid loss of potassium which could be partially reversed by 5-HT. During 5-HT stimulation, the addition of ouabain had no effect on a number of parameters including the rate of fluid secretion, the ionic composition of the saliva and the intracellular level of potassium. The possibility that potassium enters the cells passively is discussed.

Studies on the mechanism of fluid secretion by isolated salivary glands of Calliphora

1976 ◽  
Vol 64 (2) ◽  
pp. 311-322
Author(s):  
M. J. Berridge ◽  
B. D. Lindley ◽  
W. T. Prince
Keyword(s):  
Salivary Glands ◽  
Apical Membrane ◽  
Potassium Concentration ◽  
Basal Membrane ◽  
Fluid Secretion ◽  
Sodium Permeability ◽  
Bathing Medium ◽  
Major Cation ◽  
Diuretic Agent ◽  
External Potassium

1. Potassium is the major cation in the secretion of the salivary glands of Calliphora and is necessary for full secretory rates. 2. Other ions (rubidium and sodium) can support secretion in the absence of potassium. 39. During stimulation with 5-HT a Nernst plot of the basal membrane potential has a slope of 53 mV for a tenfold change in external potassium concentration and the slope at rest deviates from this over the range I-20 mM external potassium. 4. Hyperpolarization of the basal membrane by 5-HT is abolished if the chloride in the bathing medium is replaced by isethionate. 5. The diuretic agent amiloride inhibits fluid secretion by a mechanism which may include a reduction in calcium entry in addition to its recognized effect on sodium permeability. 6. A model is proposed in which fluid secretion is driven by the active transport of potassium across the apical membrane with chloride following passively.

The influence of various factors on fluid secretion by in vitro salivary glands of ixodid Ticks

1976 ◽  
Vol 64 (3) ◽  
pp. 727-742
Author(s):  
W. Kaufman
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Culture Medium ◽  
Dry Weight ◽  
Fluid Secretion ◽  
Ixodid Tick ◽  
Ixodid Ticks ◽  
Mammalian Tissue ◽  
Stimulating Factor

1. Salivary glands of the female ixodid tick, Dermacentor andersoni, secrete fluid in vitro when bathed in a slightly modified version of the mammalian tissue culture medium ‘TC 199′. 2. Rate of salivation in vitro increases with progression of feeding, but there is no comparable increase in dry weight of the salivary glands during the early phase of engorgement. Engorged ticks secreted at only 25% the rate of 90–250 mg ticks, indicating that salivary gland degeneration has already begun in the very early post-engorgement stage. 3. A salivary gland stimulating factor can be detected in the nervous system but not in other tissues. 4. Male salivary glands secrete at only 1/20th the rate of female glands. Thus males probably do not use their salivary glands as osmoregulatory organs. 5. From the uniform lack of response to ACh and uniform response to DA in 7 ixodid tick species, it is suggested that the control of salivation is similar throughout the ixodid family.

The innervation of the salivary gland of the moth, Manduca sexta: evidence that dopamine is the transmitter

1975 ◽  
Vol 63 (2) ◽  
pp. 413-419
Author(s):  
H. A. Robertson
Keyword(s):  
Salivary Gland ◽  
Electron Microscope ◽  
Salivary Glands ◽  
Manduca Sexta ◽  
Fluid Secretion ◽  
Nerve Endings ◽  
Histochemical Technique

1. Using the Falck-Hillarp histochemical technique for monoamines, evidence was found for the presence of a catecholamine in the salivary gland nerves of the moth, Manduca sexta. 2. The innervation was studied with the electron microscope. Only the fluid-secreting region of the gland is innervated and the nerve endings are characteristic of monoamine-containing terminals. 3. Using a sensitive enzymatic-isotopic assay for catecholamines, it was found that whole salivary glands contain 0.33 mug/g dopamine but no noradrenaline. 4. It seems likely that dopamine mediates fluid-secretion in the salivary gland of Manduca as it does a number of other arthropods.

Titration of sulphates and lead using lead ion selective electrode

1981 ◽  
Vol 46 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Josef Veselý
Keyword(s):  
Ionic Strength ◽  
Electrode Surface ◽  
Salt Content ◽  
Ion Selective Electrode ◽  
Lead Ion ◽  
Selective Electrode ◽  
Limit Of Determination ◽  
Total Salt Content ◽  
Automatic Titration

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.

Association of benflurone in aqueous solutions studied by measuring the activity of chloride ions

1986 ◽  
Vol 51 (11) ◽  
pp. 2437-2443
Author(s):  
František Kopecký ◽  
Mária Vojteková ◽  
Milan Pešák
Keyword(s):  
Aqueous Solutions ◽  
Chloride Ions ◽  
Ion Selective Electrode ◽  
Selective Electrode ◽  
Measured Range

The conventional activity of chloride ions was measured by an ion-selective electrode at 25 °C in aqueous solutions of benflurone, i.e. 5-(2-(N,N-dimethylamino)ethoxy)-7-oxo-7H-benzo(c)fluorene hydrochloride, without or with additions of KCl. These results suggest a gradual association of benflurone; the formation of a hetero-associate, (BH+)2Cl-, followed by higher associates was evaluated in the measured range up to 0.1 mol l-1.

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