Effects of morphine on human nasal cilia beat frequency in vitro

Abstract

Using human nasal cytological brushings, we have investigated the effects of morphine on ciliary function by measurement of cilia beat frequency in vitro, and we have also determined opioid receptor binding in these specimens. We obtained ciliated samples from seven volunteers, and measured cilia beat frequency using the transmitted light technique during exposure to morphine 10 mumol litre-1 for 4 h. Mean cilia beat frequency of the samples exposed to morphine was 11.1 (95% confidence interval 10.9-11.5) Hz and that of the controls 11.3 (11.1-11.7) Hz. There was no significant effect of morphine on human cilia beat frequency in vitro (MANOVA for repeated measures and nested, F = 0.61, P = 0.66). In a separate study, we obtained nasal brushings from 20 patients and measured the binding of the opioid antagonist tritiated diprenorphine ([3H]DPN). Mean disintegrations per minute (dpm) for total and non-specific binding were 9036 (8105-9967) dpm and 9130 (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.

Comparison of isoflurane with propofol on respiratory cilia

“…In previous work we have shown that a bolus dose of propofol has no effect on nasal cilia beat frequency measured 1 h later 13 and in another investigation we showed there were no opioid receptors on the nasal cilia. 15 Therefore, a bolus of propofol and fentanyl would not be expected to have an effect on cilia beat frequency. Baseline cilia beat frequency was similar in the two groups and is in close agreement with that reported previously in awake volunteers.…”

Bronchial mucus transport velocity in patients receiving anaesthesia with propofol and morphine or propofol and remifentanil

“…In contrast, Wang and coworkers [2] concluded from an in vivo study on dogs that the observed decrease in mucociliary clearance was more likely caused by an opioid induced reduction of ciliary beat frequency, rather than decreased mucus production or an increase in periciliary fluid. Selwyn et al [1] did not find a significant change in ciliary beat frequency in vitro after exposure of human nasal cilia to morphine. However, these contradictory results from in vitro trials might not be applicable to humans in vivo, as they do not account for the possible neural control of BTV [18].…”

“…In vitro morphine does not reduce cilia beat frequency, a key factor determining bronchial mucus transport velocity (BTV) [1]. However, both in vivo and in vitro animal studies indicate that some opioids may affect BTV [2][3][4].…”

Identifying and Understanding Risk Factors for Instability and Adverse Events Associated With Chest Physiotherapy in Ventilated Children

“…Wang et al (2003) reported decreased mucociliary clearance due to an opioid induced reduction in cilia beat frequency. However no significant change in cilia beat frequency was reported after exposure to morphine in an in-vitro study using human nasal epithelium (Selwyn et al, 1996).…”