INFLUENCE OF AGING 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 influen ce 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 incre ased from 0.9 to 16.3 months, CBF decreased from 20.2 to 6.9 Hz. 3. Th e effect of leukotriene D4 (LTD4) on CBF was also examined using trach eal explants from guinea-pigs of varying ages. The lower CBF of the ol der animal was increased by LTD4 to a larger extent than was the highe r 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 consi deration when comparing the results of different studies on the effect s of xenobiotics on mucociliary function.