[Functional identification of the TRPM8 cold receptor in rat prostate epithelial cells]

For the first time by means of electrophysiology we demonstrate functional expression of cold/menthol sensitive TRPM8 channel in secretory epithelial cells plasma membrane from rat prostate. Under whole-cell patch-clamp technique rapid cooling from 33 to 21 degrees C of freshly isolated rat prostate epithelial cells elicited the significant outward rectifying membrane current with close to 0 mV reversal potential characteristic of TRPM8 activation. Extracellular application of chemical analog of cooling, menthol (100 microM) at 33 degrees C evoked similar current responses. Cold- and menthol-evoked currents could be detected only in elongated epithelial cells, which in prostate slices were labeled with anti-cytokeratin 8, suggesting that they belong to the apical secretory phenotype. No such current could be detected in round apparently basal epithelial cells. We conclude that in normal rat prostate functional expression of TRPM8 is restricted to plasma membrane of luminal apical epithelial cells.