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

2002 ◽  
Vol 92 (6) ◽  
pp. 2396-2402 ◽  
Author(s):  
Jeffrey I. Frohock ◽  
Corrine Wijkstrom-Frei ◽  
Matthias Salathe

β2-Adrenergic agonists stimulate ciliary beat frequency (CBF), an integral part of mucociliary clearance. To evaluate the differential effects of albuterol enantiomers and their racemic mixture on ciliary function, CBF and intracellular calcium were measured at room temperature from single ovine airway epithelial cells with use of digital videomicroscopy. Baseline CBF was 7.2 ± 0.2 (SE) Hz ( n = 80 measurements). R-albuterol (10 μM to 1 mM) stimulated CBF in a dose-dependent manner to maximally 24.4 ± 5.4% above baseline. Racemic albuterol stimulated CBF to maximally 12.8 ± 3.6% above baseline, a significantly lower increase compared with R-albuterol alone, despite identical R-enantiomer amounts in both groups. Simultaneous recordings of intracellular calcium concentration and CBF from single cells indicated that the CBF increase in response to R-albuterol was mediated through β-receptors and stimulation of protein kinase A, in a calcium-dependent and -independent fashion. S-albuterol had a negligible effect on CBF and did not change intracellular calcium. Together, these results suggest that R-albuterol is more efficacious than racemic albuterol in stimulating CBF. Thus S-albuterol may interfere with the ability of R-albuterol to increase CBF.

2018 ◽  
Vol 19 (12) ◽  
pp. 3754 ◽  
Author(s):  
Taka-aki Inui ◽  
Makoto Yasuda ◽  
Shigeru Hirano ◽  
Yukiko Ikeuchi ◽  
Haruka Kogiso ◽  
...  

The effects of the isoflavone daidzein on the ciliary beat distance (CBD, which is a parameter assessing the amplitude of ciliary beating) and the ciliary beat frequency (CBF) were examined in ciliated human nasal epithelial cells (cHNECs) in primary culture. Daidzein decreased [Cl−]i and enhanced CBD in cHNECs. The CBD increase that was stimulated by daidzein was mimicked by Cl−-free NO3− solution and bumetanide (an inhibitor of Na+/K+/2Cl− cotransport), both of which decreased [Cl−]i. Moreover, the CBD increase was inhibited by 5-Nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, a Cl− channel blocker), which increased [Cl−]i. CBF was also decreased by NPPB. The rate of [Cl−]i decrease evoked by Cl−-free NO3− solution was enhanced by daidzein. These results suggest that daidzein activates Cl− channels in cHNECs. Moreover, daidzein enhanced the microbead transport driven by beating cilia in the cell sheet of cHNECs, suggesting that an increase in CBD enhances ciliary transport. An [Cl−]i decrease enhanced CBD, but not CBF, in cHNECs at 37 °C, although it enhanced both at 25 °C. Intracellular Cl− affects both CBD and CBF in a temperature-dependent manner. In conclusion, daidzein, which activates Cl− channels to decrease [Cl−]i, stimulated CBD increase in cHNECs at 37 °C. CBD is a crucial factor that can increase ciliary transport in the airways under physiological conditions.


1995 ◽  
Vol 268 (4) ◽  
pp. L596-L600 ◽  
Author(s):  
J. H. Sisson

The mucociliary apparatus of the lung provides an important host-defense function by clearing the upper airway of inhaled particles and infectious microorganisms. Because lung host defenses are impaired in alcoholics, we hypothesized that ethanol would decrease ciliary motility in airway epithelium. Ciliary beat frequency (CBF) was measured by videomicroscopy in primary cultures of ciliated bovine bronchial epithelial cells (BBECs). Ethanol rapidly stimulated ciliary motility in a time-dependent fashion with concentrations as low as 10 mM. No detectable decreases in ciliary motility were noted until ethanol concentrations exceeded 1,000 mM. Because many substances stimulate ciliary motility by releasing nitric oxide (NO) via upregulation of nitric oxide synthase (NOS), we preincubated ciliated BBECs with a stereospecific NOS inhibitor, NG-monomethyl-L-arginine (L-NMMA). L-NMMA completely blocked ethanol-induced stimulation of CBF, which could be subsequently restored by adding either L-arginine or sodium nitroprusside, which is a direct NO donor. These results indicate that ethanol, at clinically relevant concentrations, stimulates the release of NO by airway epithelium that upregulates ciliary motility. The rapidity of this response suggests upregulation of the constitutive NOS, known to be present in airway epithelium, and may explain the increases in mucociliary clearance observed in previous studies of ethanol ingestion in animals and in humans. These data also suggest a novel signal transduction pathway, the NO/NOS system, by which ethanol may exert some of its diverse biologic effects.


1998 ◽  
Vol 275 (4) ◽  
pp. L827-L835 ◽  
Author(s):  
T. A. Wyatt ◽  
J. R. Spurzem ◽  
K. May ◽  
J. H. Sisson

Ciliary beating is required for the maintenance of lung mucociliary transport. We investigated the role of cyclic nucleotide-dependent protein kinases in stimulating ciliary beat frequency (CBF) in bovine bronchial epithelial cells (BBECs). cAMP-dependent protein kinase (PKA) activity and cGMP-dependent protein kinase (PKG) activity were distinguished after DEAE-Sephacel chromatography of BBEC extracts. cAMP levels and PKA activity are increased in BBECs stimulated with 0.01–1 mM isoproterenol, with a corresponding increase in CBF. cGMP levels and PKG activity are increased in BBECs stimulated with 0.1–10 μM sodium nitroprusside, with a corresponding increase in CBF. Direct protein kinase-activating analogs of cAMP and cGMP (dibutyryl cAMP and 8-bromo-cGMP, respectively) also activate their specific kinases and stimulate CBF. Preincubation of BBECs with inhibitors of PKA or PKG [KT-5720 or Rp-8-( p-chlorophenylthio)-guanosine 3′,5′-cyclic monophosphothioate] results in the inhibition of specific kinase activity as well as in the inhibition of CBF. These studies suggest that the activation of either PKA or PKG can lead to the stimulation of CBF in bovine airway epithelium.


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