Muco-ciliary transport is a major respiratory tract host defense mechanism that works against inhaled microbes and noxious materials. Cilia movement is an essential point for this fundamental defense mechanism. The ciliary beat frequency is a quantitative measurement of ciliary beats and the most important factor responsible for regulating muco-ciliary transport.
Nasal mucosa (mucosa + cells) was obtained from 18 patients (10 males, 8 females). One sample was obtained from each of three patients and each measurement was performed three times. The cultured nasal mucosa was used for measurement of the ciliary beat frequency with and without protein kinase C (PKC) inhibitor (agents that activate PKC have been associated with decreasing ciliary beat frequency). Normal nasal epithelial cells were used to examine the cytotoxicity of exposure to an 1.8 GHz electromagnetic field.
|Exposure duration||continuous for 3 days|
In nasal mucosa cells of the exposed group, the ciliary beat frequency began to decrease compared to the control samples from the beginning of the exposure with a maximum difference after three days. A significant increase in the enzyme activity of protein kinase C was observed in exposed samples in comparison to control samples. An incubation of the exposed sample with the protein kinase C inhibitor Calphostin C abolished the exposure induced decrease of the ciliary beat frequency. The addition of the protein kinase C inhibitor Gö-6976 did not affect the ciliary beat frequency neither in the exposed nor in the control group. However, the addition of the protein kinase C inhibitor GF 109203X prevented any exposure induced decrease of the ciliary beat frequency.
In nasal epithelial cells, no significant difference was observed in the cell viability between the exposed samples and the control samples.
The authors summarize that exposure to a 1.8 GHz electromagnetic field may inhibit the ciliary beat frequency via an "novel protein kinase C" dependent mechanism, but seems not to be cytotoxic in nasal epithelial cells.