Effect of Exogenous ATP on Ciliary Beat of Human Ciliated Cells Studied with Differential Interference Microscope Equipped with High Speed Video

Abstract

To study the detailed effects of exogenous adenosine triphosphate (ATP) on ciliary function, we used the differential interference microscope equipped with high speed video and evaluated ciliated cells from the human sinus mucosa in monolayer culture. With this system it was possible to evaluate all parts of ciliary motility with a minimum of interference from the mucous membrane, secretory cells and the autonomic nervous system. The best direct ciliostimulative effect of exogenous ATP on ciliary beat frequency (CBF) and ciliary beat amplitude (CBA) was observed at concentrations of ATP ranging from 10(-5) M to 10(-3) M. Exogenous ATP appeared to normalize the slightly damaged ciliary motility in groups with an initial CBF of 14 Hz or higher. When the CBF was less than 14 Hz, ATP produced an increase in CBF greater than 40%, an increase in CBA greater than 30%, but these did not reach the normal level in 5 min. The biggest increases: 59.9% in CBF and 40.7% in CBA were seen in the group with an initial CBF less than 9 Hz. In the cells with a low initial CBF and unsynchronized motility exogenous ATP increased the synchrony of ciliary movement together with an increase in CBF and CBA.

Effects of albuterol enantiomers on ciliary beat frequency in ovine tracheal epithelial cells

“…The cells were exposed to 10 M ATP to ascertain their response to a known, but different, stimulator of CBF (9,32,39). The maximal increases in CBF with ATP exposure were 22.4 Ϯ 2.5% above the pre-ATP baseline in the R-albuterol group (n ϭ 25; no significant differences between the increases at each R-albuterol concentration), 22.1 Ϯ 2.7% above pre-ATP baseline in the S-albuterol group (n ϭ 21), and 18.4 Ϯ 2.3% above pre-ATP baseline in the racemic albuterol group (n ϭ 29).…”

Role of mechanical stress in regulating airway surface hydration and mucus clearance rates

“…The net effect of these processes is the stimulation of fluid secretion in the airways, hydrating both the PCL and the overlying mucus layer, facilitating its clearance. It should be pointed out, as discussed below, that the increase in Ca 2+ i by activation of P2Y 2 receptors can modulate the activity of other cellular processes in addition to changes in ion transport, including activation of mucin secretion (Lethem et al, 1993) and increasing the rate of ciliary beating (Yoshitsugu et al, 1993;Winters et al, 2007). Importantly, studies have demonstrated that the net result of this activation by exogenous luminal ATP is an increased mucus clearance rates (Bennett et al, 2001).…”

Ciliary functional analysis: Beating a path towards standardization

“…To study human respiratory cilia, epithelial specimens have been obtained from nasal turbinates, nasal polyps, tonsils, the maxillary sinus, trachea, and bronchi . Studies found no significant differences between CBF of cilia obtained from these sites, with the nasal brushing and tracheal biopsy specimens having superior quality .…”

“…There is a lack of agreement concerning the CBA definition . CBA has been defined as the distance travelled between the maximum forward and backwards movements of the cilia tip, or as the angle between the cilium body in the end position of an effective stroke and a recovery stroke (which is only an indicator of the CBA, due to the flexible nature of the beat) …”