[Gender differences in cold sensitivity: role of hormonal regulation of TRPM8 channel].

We have studied the gender differences in the perception of cutaneous cold stimuli in the innocuous temperature range (5-30 degrees C) in mice and rats. In the behavioral tests using two variable temperature plates technique female subjects displayed lower threshold for the sensation of cooling temperatures in the range of 15-25 degrees C compared to males. Patch-clamp experiments carried out on dorsal root ganglion (DRG) neurons from male and female rats maintained in the short-term cultures in the presence of testosterone or 17beta-estradiol, respectively, have revealed gender- and hormone-related differences in the electrophysiological properties of cold/menthol-sensitive TRPM8 channel: average density of menthol-activated I(TRPM8) current density in females' DRG neurons was higher compared to males', and the steady-state voltage-dependent activation curve of TRPM8 in females was shifted towards hyperpolarized potentials compared to males. These distinctive TRPM8 properties vanished upon withdrawal of testosterone and 17beta-estradiol from the culture mediums. We conclude that the observed differences in the behavioural sensitivity to innocuous cold and in functional properties of TRPM8 cold receptor are due to differential regulation of TRPM8 by sex steroid hormones, testosterone and/or 17beta-estradiol.