Effect of ethanol on epidermal growth factor receptor in buccal mucosa.

The effect of ethanol on buccal mucosal epidermal growth factor receptors was investigated. The buccal mucosal cells from adult rats were incubated in DMEM at 4 degrees C and 37 degrees C in the presence of various concentrations (0-5%) of ethanol and then assayed for EGF receptor binding using [125I]-EGF. The results of binding analysis showed that the cells incubated in the presence of ethanol displayed diminished [125I]-EGF binding. The receptor binding capacity was dependent upon ethanol concentration and was more pronounced at 4 degrees C. A 30% decrease in receptor binding occurred with 1% ethanol, 34% with 2.5% ethanol, while 5% ethanol caused a 42% decrease in binding. Scatchard analysis suggested that the decrease of [125I]-EGF binding to the buccal mucosal cells pre-incubated with ethanol was due to a decrease of the high affinity binding site (Bmax). The association constant of the high affinity EGF receptor remained unchanged. The results suggest that ethanol due to its untoward effect on the receptor binding of salivary GF interferes with the process of epithelial renewal, thus leading to weakening of the mucosal defense perimeter of soft oral tissue and the onset of dysplasia.