xe-991--anthracenone and carvacrol

Skin keratinocytes fulfil important signalling and protective functions. Immunocytochemical experiments revealed the unexpected presence of immunoreactivity for the M-type potassium channel subunit Kv7.2 in the keratinocyte layer of intact rat paw skin and in keratinocytes isolated from the skin of 1-day-old rats and cultured in vitro for 3-10 days. Application of the M-channel enhancer retigabine (3-10 μM) to isolated cultured rat keratinocytes: (a) increased outward membrane currents recorded under voltage clamp, (b) produced ~3 mV hyperpolarization at rest, (c) enhanced ~3-fold the release of ATP induced by the TRPV3 agonist carvacrol (1 mM) and (d) increased the amplitude of the carvacrol-induced intracellular Ca(2+) transient measured with Fura-2. The effect of retigabine on ATP release was prevented by the M-channel blocking agent XE991. We conclude that rat skin keratinocytes possess M-channels that, when activated, can modify their physiological properties, with potential significance for their sensory and other biological functions.

Topics: Action Potentials; Adenosine Triphosphate; Animals; Anthracenes; Calcium; Carbamates; Cells, Cultured; Cymenes; KCNQ2 Potassium Channel; Keratinocytes; Monoterpenes; Phenylenediamines; Potassium Channel Blockers; Rats; Rats, Sprague-Dawley; Skin; TRPV Cation Channels