Measurement of membrane potential inBacillus subtilis: A comparison of lipophilic cations, rubidium ion, and a cyanine dye as probes

1981 ◽  
Vol 63 (3) ◽  
pp. 215-231 ◽  
Author(s):  
Arieh Zaritsky ◽  
May Kihara ◽  
Robert M. Macnab
Keyword(s):  
Membrane Potential ◽  
Cyanine Dye ◽  
Lipophilic Cations

The use of a cyanine dye in measuring membrane potential in yeast

1984 ◽  
Vol 231 (1) ◽  
pp. 217-225 ◽  
Author(s):  
Antonio Peña ◽  
Salvador Uribe ◽  
Juan P. Pardo ◽  
Miguel Borbolla
Keyword(s):  
Membrane Potential ◽  
Cyanine Dye

scholarly journals PMN heterogeneity: long-term stability of fluorescent membrane potential responses to the chemoattractant N-formyl-methionyl-leucyl- phenylalanine in healthy adults and correlation with respiratory burst activity

Blood ◽  
1986 ◽  
Vol 68 (3) ◽  
pp. 611-618 ◽  
Author(s):  
MP Fletcher ◽  
BE Seligmann
Keyword(s):  
Membrane Potential ◽  
Respiratory Burst ◽  
Healthy Adults ◽  
Polymorphonuclear Neutrophils ◽  
Cyanine Dye ◽  
Potential Response ◽  
Long Term Stability ◽  
Nbt Reduction ◽  
Wbc Count ◽  
Immature Cells

Abstract Polymorphonuclear neutrophils (PMNs) were isolated from 24 healthy adults 20 to 61 years of age and the proportion of cells that demonstrated depolarization responses to the synthetic chemotaxin N- formyl-methionyl-leucyl-phenylalanine (FMLP) were enumerated using the lipophilic fluorescent cyanine dye 3,3′-di-pentyl-oxacarbocyanine [di-O- C(5)(3)] and flow cytometry. The membrane potential responses were correlated to the cells' respiratory burst capabilities as measured by nitroblue tetrazolium (NBT) reduction and/or superoxide production in response to FMLP; 40.2% +/- 15.1% (mean +/- SD) of cells depolarized to FMLP. The mean SE for duplicate determinations 1 hour apart was 3.8% (range 0.4% to 13.6%, n = 15). There was no correlation between the percentage of depolarizing PMNs and the yield of cells, the percentage of immature cells, or the circulating WBC count. There was no difference in the average age of men (34.9 +/- 9.9 years, n = 11) v women (33.8 +/- 8.5, n = 13) (mean +/- SD) studied, or in the percentage of depolarizing PMNs when men and women were compared (42.2 +/- 10.6% v 43.1 +/- 13.3%, respectively). However, there was a significant increase in the percentage of depolarizing PMNs with increasing age of women (r = .61, P less than .025) but not men (r = .03, P greater than .05). Analysis of variance revealed significantly greater person-to-person variability in the membrane potential response than in day-to-day variability in the same person (P less than .0005). The percentage of depolarizing PMNs in response to FMLP was significantly correlated with the percentage of NBT-positive cells from both purified PMNs and from whole blood (r = .849, P less than .0005, r = .857, P less than .05, respectively), and with the amount of superoxide produced, expressed as a percentage of that amount produced by cytochalasin B (cyto-B)-pretreated cells (r = .565, P less than .01). The data indicate that PMNs from healthy adults demonstrate a heterogeneous membrane potential response to the chemotaxin FMLP that correlates with the cells' oxidative responsiveness and that intersubject differences can be detected. In addition, the proportion of responsive PMNs increases with increasing age in women.

scholarly journals Defective membrane potential changes in neutrophils from human neonates.

1984 ◽  
Vol 160 (4) ◽  
pp. 1247-1252 ◽  
Author(s):  
F Sacchi ◽  
H R Hill
Keyword(s):  
Membrane Potential ◽  
Polymorphonuclear Leukocytes ◽  
Inflammatory Mediator ◽  
Fluorescence Emission ◽  
Marked Change ◽  
Cyanine Dye ◽  
Free Calcium ◽  
Marked Contrast ◽  
Free Intracellular Calcium ◽  
Human Neonates

In an attempt to determine the mechanism of the profound defect in chemotaxis observed in the polymorphonuclear leukocytes (PMN) of human neonates, we have examined membrane potential changes and alterations in free intracellular calcium following chemotactic factor stimulation. Following exposure to formyl-methionyl-leucyl-phenylalanine (FMLP), PMN from adult donors (11) showed a marked change in membrane potential (31%) as determined by fluorescence emission using the cyanine dye, 3-3-dipentyloxacarbocyanine [DiOC5(3)]. In marked contrast, FMLP-stimulated PMN from 10 human neonates failed to show any significant change in membrane potential (1-2%). Using the calcium-sensitive probe Quin 2/AM, FMLP induced an increase in fluorescence of up to 51% in adult PMN (10). In contrast, the change in intracellular free calcium induced in neonatal PMN was much less (32%; P less than 0.01). These results suggest that the profound defect in chemotactic responsiveness of PMN from human neonates may result from an inability of these cells to undergo changes in membrane potential following inflammatory mediator stimulation.

scholarly journals Alterations in The Trans-Membrane Potential of Human Blood Platelets in Response to Aggregating Stimuliow

1977 ◽  
Author(s):  
W. C. Horne ◽  
N. E. Larsen ◽  
E. R. Simons
Keyword(s):  
Membrane Potential ◽  
Blood Platelets ◽  
Human Platelets ◽  
Cyanine Dye ◽  
Secretory Cells ◽  
Coupling Mechanism ◽  
Stimulus Response ◽  
Low Concentrations ◽  
Dye Aggregation ◽  
Coupling Mechanisms

It has been suggested that the mechanism of response of platelets to aggregating stimuli is analogous to the stimulus-response coupling mechanisms of muscle and secretory cells. Because the coupling mechanisms of both types of systems involve changes in the trans-membrane potential of the stimulated cell, we have examined the membrane potential of human platelets to determine if the potential changes in response to aggregating agents. The membrane potential of gel-filtered platelets was monitored using a fluorescent cyanine dye. Aggregation was prevented to minimize artifacts due to changes in light scattering. The effects of ADP, thrombin, and collagen on the potential were examined. In response to ADP, the membrane rapidly became more negatively polarized. The response was concentration dependent, the minimum response occurring with 3x10-5M ADP. The response to thrombin was more complex. Low concentrations (0.01 U/ml) produced a change similar to that caused by ADP. Higher concentration (1–10 U/ml) led to a rapid decrease in the polarization of the membrane. When pre-formed collagen fibrils were added, in the presence of creatine Phosphokinase to destroy released ADP, no changein the potential was observed.Thus the platelet membrane potential changes in response to aggregating stimuli, supporting the hypothesis that stimulus of platelet aggregation is analogous to other stimulus-response coupling mechanisms. The change in potential is not a necessary step in the coupling mechanism. The different responses to specific agents indicate that the agents may trigger aggregation through different mechanisms.

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