EFFECTS OF MORPHINE ON HUMAN NASAL CILIA BEAT FREQUENCY IN-VITRO

Using human nasal cytological brushings, we have investigated the effe cts of morphine on ciliary function by measurement of cilia beat frequ ency in vitro, and we have also determined opioid receptor binding in these specimens. We obtained ciliated samples from seven volunteers, a nd measured cilia beat frequency using the transmitted light technique during exposure to morphine 10 mu mol litre(-1) for 4 h. Mean cilia b eat frequency of the samples exposed to morphine was 11.1 (95% confide nce interval 10.9-11.5) Hz and that of the controls 11.3 (11.1-11.7) H z. There was no significant effect of morphine on human cilia beat fre quency in vitro (MANOVA for repeated measures and nested, F = 0.61, P = 0.66). In a separate study, we obtained nasal brushings from 20 pati ents and measured the binding of the opioid antagonist tritiated dipre norphine([H-3] DPN). Mean disintegrations per minute (dpm) for total a nd non-specific binding were 9036 (8105-9967) dpm and 9830 (8054-10206 ) dpm, respectively. These values did not differ significantly (paired t test, t = 0.22, P = 0.83). We conclude that morphine had no effect on cilia beat frequency in vitro and we were unable to demonstrate any significant numbers of opioid receptors on nasal ciliated epithelium.