Influence of ageing on ciliary beat frequency and on ciliary response to leukotriene D4 in guinea-pig tracheal epithelium.

1. In the present study on guinea-pig tracheal epithelium, the influence of age on ciliary beat frequency (CBF) was investigated. 2. An age-dependent decrease in CBF was seen: as the age of the guinea-pig increased from 0.9 to 16.3 months, CBF decreased from 20.2 to 6.9 Hz. 3. The effect of leukotriene D4 (LTD4) on CBF was also examined using tracheal explants from guinea-pigs of varying ages. The lower CBF of the older animal was increased by LTD4 to a larger extent than was the higher CBF seen in explants taken from younger animals. 4. Ciliary activity and possibly also the sensitivity of the cilia to drugs, seems to be dependent upon the age of the animal, which has to be taken into consideration when comparing the results of different studies on the effects of xenobiotics on mucociliary function.