The study of ciliary frequencies with an optical spectrum analysis system

Kennedy, John R.; Duckett, K.E.

doi:10.1016/0014-4827(81)90307-4

Cited by 72 publications

(36 citation statements)

References 18 publications

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“…The magnitude of the reduction of CBF, however, was much smaller in our study, with a maximal decrease of -10 % in comparison to -50 % reported by the above workers. The characteristics of the TFP-dependent inhibition of the basal CBF (with a plateau 10% below baseline) together with the ability of the ciliated cells to respond to the rise in temperature, a physical stimulus known to increase the activity of ciliated cells (Kennedy & Duckett, 1981), suggest that TFP did not cause 'toxic' damage to the cells. The importance of calmodulin-sensitive Ca2+-dependent enzymes in the control of CBF in mammalian respiratory epithelium is also supported by the studies of Verdugo and colleagues on rabbits cells (1983), where they observed an increase in the effect of Ca2`on the CBF of demembranated tracheal cilia by adding exogenous calmodulin.…”

Section: Effect Of Calcium Ionophore On Intracellular Free Calciummentioning

confidence: 94%

“…The wash-out time was calculated by filling the chamber with a coloured solution and measuring the rate of decline of absorbance during perfusion with distilled water. CBF was measured at room temperature (23-1 + 1-3 'C) using a photometric technique (Dalhamn & Rylander, 1962;Di Benedetto, Gill, Lopez-Vidriero & Clarke, 1989 (Kennedy & Duckett, 1981). The two methods provided similar CBF values, with differences within 0-2 Hz (r = 0-982; n = 40).…”

Section: Measurement Of Ciliary Beat Frequencymentioning

confidence: 99%

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Calcium regulation of ciliary beat frequency in human respiratory epithelium in vitro.

Benedetto

Magnus

Gray

et al. 1991

The Journal of Physiology

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SUMMARY1. The changes in ciliary beat frequency (CBF) of human nasal respiratory epithelial cells were measured in vitro with a photometric technique following exposure to either 4-bromo-calcium ionophore A23187 (4-Br-A23187) or trifluoperazine (TFP), an inhibitor of calmodulin-sensitive calcium-dependent protein kinases. Changes in intracellular free calcium concentrations in response to 4-Br-A23187 were studied using a fluorescent dye (Fura-2).2. Addition of 10' M-4-Br-A23187 caused a time-dependent (P < 001) rise in CBF. The increment in CBF was statistically significant 10 min after challenge (+ 10 %; P < 0 01) and was sustained for at least 1 h, with maximal stimulation after 40 min (+ 18 %; P < 0-01).3. Exposure to 10' M-4-Br-A23187 caused an immediate increase in intracellular free calcium concentration, which preceded the rise in CBF.4. TFP (10' M) caused a reduction of baseline CBF (-10%; P < 001) and prevented the expected rise when the cells were subsequently exposed to 10' M-4-Br-A23187.5. We conclude that: (1) calcium ionophore stimulates the CBF of human respiratory cells; (2) this effect is mediated through a calmodulin-sensitive system, since it is abolished in the presence of TFP; (3) the same pathway appears to control the basal CBF of these cells, since TFP also decreases CBF.

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Section: Effect Of Calcium Ionophore On Intracellular Free Calciummentioning

confidence: 94%

Section: Measurement Of Ciliary Beat Frequencymentioning

confidence: 99%

Calcium regulation of ciliary beat frequency in human respiratory epithelium in vitro.

Benedetto

Magnus

Gray

et al. 1991

The Journal of Physiology

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“…In an effort to obtain better photoelectronic signals, some groups chose to examine the cilia in profile [Yager et al, 1978;Dulfano et al, 1981;Naitoh and Kaneko, 1973;Rutland et al, 1981;Kennedy and Duckett, 1981;Yanaura et al, 19811. However, the results of this approach are also strongly influenced by the phenomenon of metachrony.…”

Section: Pha Se Dura Ti On V S Frequenc Y Beat (Hz) Effec T I Yementioning

confidence: 99%

A versatile and quantitative computer‐assisted photoelectronic technique used for the analysis of ciliary beat cycles

Sanderson

Dirksen

1985

Cell Motility

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The beat cycles of rabbit tracheal cilia in culture and Mytilus laterofrontal cirri were recorded using a phototransistor, transillumination, video, and phase-contrast microscopy. The photoelectronic signal and video image of the ciliary activity were simultaneously recorded as a composite image. The photoelectronic signal was converted into a digital signal by a data acquisition system for further computer processing. By the selection of a small detector area and accurate detector alignment, a simple, repetitive photoelectronic signal representing ciliary activity was obtained. This signal records the ciliary beat frequency and demonstrates the triphasic nature of the beat cycle. The photoelectronic signal can be precisely correlated with the ciliary activity by analysis of the composite video recordings to provide the duration of the effective, recovery, and rest phases of the beat cycle. The video-photoelectronic signal correlations were verified by high-speed cinematography. High-speed films of ciliary activity were digitized, and the image density of selected pixels was analyzed by computer with respect to time and ciliary motion. These studies indicate that duration of the phases of the beat cycle are differentially reduced with increased beat frequency; the effective phase duration was quickly reduced to a minimum. This was followed by the reduction of the duration of the recovery phase to a minimum. The rest phase continues to be reduced without reaching a minimum, over the range of beat frequencies observed. These results suggest that ciliary beat frequency may be regulated either by modifying the rates of dynein-microtubule interactions or the rate of transition from one beat phase to the next.

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“…The wavetops consist of extended cilia in the effective stroke and the valleys of bending cilia in the recovery stroke (Sleigh et al 1988). Amazingly rapid changes in beat frequency, even in temperature controlled measurements, are observed in cilia from rabbit respiratory mucosa (Kennedy and Duckett 1981) and cilia from frog palate epithelium, which furthermore show a large variation of beat frequency in space (Spungin and Silberberg 1984).…”

Section: Introductionmentioning

confidence: 99%

Biophysical models of ciliary activity: Gaussian frequency distributions

et al. 1990

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A model of a freely rotating extended scatterer is proposed to describe light scattering from beating cilia. Gaussian rotation frequency distributions, characterized by a mean angular frequency and a standard deviation, are introduced in order to simulate intensity autocorrelation functions and to fit the model to experimental data. Thus the ciliary beats are characterized by a mean beat frequency and a standard deviation of the beat frequency distribution. The standard deviation influences the damping of the intensity autocorrelation function of light scattered from cilia. The calculated intensity autocorrelation function shows a more prominent oscillating behaviour the smaller the standard deviation of the beat frequency. The validity of the model is supported by experimental data in two ways: 1) The model fits very well to experimental data in computer evaluations, 2) Neither the model nor information obtained from measurements are dependent on the measuring angle.

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The study of ciliary frequencies with an optical spectrum analysis system

Cited by 72 publications

References 18 publications

Calcium regulation of ciliary beat frequency in human respiratory epithelium in vitro.

Calcium regulation of ciliary beat frequency in human respiratory epithelium in vitro.

A versatile and quantitative computer‐assisted photoelectronic technique used for the analysis of ciliary beat cycles

Biophysical models of ciliary activity: Gaussian frequency distributions

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